Analysis of Urban Terrain Data for Use in the Development of an Urban Camouflage Pattern

DTIC Science & Technology

1990-02-01

the entire lightness gamut , but concentrated in the red, orange, yellow and neutral regions of color space. 20. DISTRIBUTION I AVAILABILITY OF...le·nents grouped by color. ) Summary of Scenes Filmed for Urban Camouflage Study. 01Jtirnum Number of Do·nains Separated by Type; Sele:::ted CIELAB ...Values for All Urban Scenes. Selected CIELAB Values for Type I Urban Scenes. Selected CIELAB Values for Type II Urban Scenes. v Page 3 6 7 8 9

Spectrophotometric color measurement for early detection and monitoring of greening on granite buildings.

PubMed

Sanmartín, P; Vázquez-Nion, D; Silva, B; Prieto, B

2012-01-01

This paper addresses the detection and monitoring of the development of epilithic phototrophic biofilms on the granite façade of an institutional building in Santiago de Compostela (NW Spain), and reports a case study of preventive conservation. The results provide a basis for establishing criteria for the early detection of phototrophic colonization (greening) and for monitoring its development on granite buildings by the use of color changes recorded with a portable spectrophotometer and represented in the CIELAB color space. The results show that parameter b* (associated with changes of yellowness-blueness) provides the earliest indication of colonization and varies most over time, so that it is most important in determining the total color change. The limit of perception of the greening on a granite surface was also established in a psycho-physical experiment, as Δb*: +0.59 CIELAB units that correspond, in the present study, to 6.3 μg of biomass dry weight cm(-2) and (8.43 ± 0.24) × 10(-3) μg of extracted chlorophyll a cm(-2).

Exploring s-CIELAB as a scanner metric for print uniformity

NASA Astrophysics Data System (ADS)

Hertel, Dirk W.

2005-01-01

The s-CIELAB color difference metric combines the standard CIELAB metric for perceived color difference with spatial contrast sensitivity filtering. When studying the performance of digital image processing algorithms, maps of spatial color difference between 'before' and 'after' images are a measure of perceived image difference. A general image quality metric can be obtained by modeling the perceived difference from an ideal image. This paper explores the s-CIELAB concept for evaluating the quality of digital prints. Prints present the challenge that the 'ideal print' which should serve as the reference when calculating the delta E* error map is unknown, and thus be estimated from the scanned print. A reasonable estimate of what the ideal print 'should have been' is possible at least for images of known content such as flat fields or continuous wedges, where the error map can be calculated against a global or local mean. While such maps showing the perceived error at each pixel are extremely useful when analyzing print defects, it is desirable to statistically reduce them to a more manageable dataset. Examples of digital print uniformity are given, and the effect of specific print defects on the s-CIELAB delta E* metric are discussed.

High correlation between skin color based on CIELAB color space, epidermal melanocyte ratio, and melanocyte melanin content.

PubMed

Huang, Wen-Shyan; Wang, Yi-Wen; Hung, Kun-Che; Hsieh, Pai-Shan; Fu, Keng-Yen; Dai, Lien-Guo; Liou, Nien-Hsien; Ma, Kuo-Hsing; Liu, Jiang-Chuan; Dai, Niann-Tzyy

2018-01-01

To treat skin color disorders, such as vitiligo or burns, melanocytes are transplanted for tissue regeneration. However, melanocyte distribution in the human body varies with age and location, making it difficult to select the optimal donor skin to achieve a desired color match. Determining the correlations with the desired skin color measurement based on CIELAB color, epidermal melanocyte numbers, and melanin content of individual melanocytes is critical for clinical application. Fifteen foreskin samples from Asian young adults were analyzed for skin color, melanocyte ratio (melanocyte proportion in the epidermis), and melanin concentration. Furthermore, an equation was developed based on CIELAB color with melanocyte ratio, melanin concentration, and the product of melanocyte ratio and melanin concentration. The equation was validated by seeding different ratios of keratinocytes and melanocytes in tissue-engineered skin substitutes, and the degree of fitness in expected skin color was confirmed. Linear regression analysis revealed a significant strong negative correlation ( r  =  - 0.847, R 2  = 0.717) between CIELAB L * value and the product of the epidermal melanocyte ratio and cell-based melanin concentration. Furthermore, the results showed that an optimal skin color match was achieved by the formula. We found that L * value was correlated with the value obtained from multiplying the epidermal melanocyte ratio (R) and melanin content (M) and that this correlation was more significant than either L * vs M or L * vs R. This suggests that more accurate prediction of skin color can be achieved by considering both R and M. Therefore, precise skin color match in treating vitiligo or burn patients would be potentially achievable based on extensive collection of skin data from people of Asian descent.

A Method of Classifying Tongue Colors for Traditional Chinese Medicine Diagnosis Based on the CIELAB Color Space

NASA Astrophysics Data System (ADS)

Li, Bocong; Huang, Qingmei; Lu, Yan; Chen, Songhe; Liang, Rong; Wang, Zhaoping

Objective tongue color analysis is an important research point for tongue diagnosis in Traditional Chinese Medicine. In this paper a research based on the clinical process of diagnosing tongue color is reported. The color data in RGB color space were first transformed into the data in CIELAB color space, and the color gamut of the displayed tongue was obtained. Then a numerical method of tongue color classification based on the Traditional Chinese Medicine (for example: light white tongue, light red tongue, red tongue) was developed. The conclusion is that this research can give the description and classification of the tongue color close to those given by human vision and may be carried out in clinical diagnosis.

Anthocyanins of Jambolão (Syzygium cumini): Extraction and pH-Dependent Color Changes.

PubMed

do Carmo Brito, Brenda de Nazaré; da Silva Pena, Rosinelson; Santos Lopes, Alessandra; Campos Chisté, Renan

2017-10-01

Jambolão fruits are promising sources of anthocyanins, and in this study, the jambolão fruit from the Brazilian Amazonian region was characterized and the efficiency of six ethanol-based solutions to extract anthocyanins was determined. Moreover, the color changes of anthocyanin extracts, as influenced by different pH conditions (pH from 1.0 to 8.0), were evaluated. The fruits exhibited high contents of total anthocyanins (296 mg/100 g) and the CIELAB parameters characterized jambolão as a purple-red colored fruit (a* = 20.30, b* = -4.17, and hab∘= 348.39). Among the six different ethanol-based solutions, ethanol 95% with 1% of HCl (v/v) was the most efficient solution to extract anthocyanins from jambolão fruits. Furthermore, the CIELAB parameters were characterized as useful tool to monitor the color changes of anthocyanins of jambolão over the tested pH range. Therefore, jambolão fruits from Amazonian region have technological potential for the application by food, pharmaceutical, and cosmetic industries. Jambolão fruits are great source of anthocyanins and the incorporation of these natural pigments as food colorants is not only valuable to improve overall appearance, but it is also beneficial to human health. The production of natural extracts with high levels of anthocyanins from jambolão can be considered a very useful approach to the food, pharmaceutical and cosmetic industries. © 2017 Institute of Food Technologists®.

A model for prediction of color change after tooth bleaching based on CIELAB color space

NASA Astrophysics Data System (ADS)

Herrera, Luis J.; Santana, Janiley; Yebra, Ana; Rivas, María. José; Pulgar, Rosa; Pérez, María. M.

2017-08-01

An experimental study aiming to develop a model based on CIELAB color space for prediction of color change after a tooth bleaching procedure is presented. Multivariate linear regression models were obtained to predict the L*, a*, b* and W* post-bleaching values using the pre-bleaching L*, a*and b*values. Moreover, univariate linear regression models were obtained to predict the variation in chroma (C*), hue angle (h°) and W*. The results demonstrated that is possible to estimate color change when using a carbamide peroxide tooth-bleaching system. The models obtained can be applied in clinic to predict the colour change after bleaching.

Comparison of two color-difference formulas using the Bland-Altman approach based on gingiva color space.

PubMed

Gómez Polo, Cristina; Montero, Javier; Martín Casado, Ana Maria

2018-04-23

The objectives of this study were to determine the relationship between the results provided by the classical CIELab (ΔE ab *) and the CIEDE2000 (ΔE00) formulas and the gingival color space using the Bland and Altman limits of agreement, to use this relationship to establish the equivalences between the gingival color thresholds of perceptibility of both formulas, and to evaluate whether the relationship between ΔE ab * and ΔE00 is modified depending on the axis in which the changes occur. The means of the L*, a*, and b* coordinates of the 21 gingiva porcelain samples (Heraceram, Heraeus Kulzer Mitsui Chemical Groups) were used and the differences in color were calculated in 210 pairs of samples using the CIELab (ΔE*ab) and CIEDE2000 (ΔE00) color-difference formulas. The results obtained with these formulas were compared and the limits of agreement after a logarithmic transformation of the data were obtained. The relationship between both formulas was ln ΔE 00  = - 0.22 + ln ΔE ab *. The results obtained with the CIELab formula were between 1.01 (95% confidence interval 0.98-1.03) and 1.54 (95% confidence interval 1.52-1.59) times higher than those obtained with the CIEDE200 formula. In the gingiva color space, the scale factor between the CIEDE2000 and CIELab values changes from 0.63 to 1.02, such that providing an accurate scale factor between both values proves difficult. The pairs with the highest ratio were those where the difference in color was mainly due to changes in lightness, whereas the pairs with the smallest ratio were those where the difference in color was mainly due to changes in the blue-yellow or green-red axes.

Modeling of Carbon Mortar Color Expression Using Artificial Neural Network.

PubMed

Jang, Hong-Seok; Kim, Ju-Hee; Shuli, Xing; So, Seung-Young

2018-09-01

Colored concrete uses pigments and white Portland cement (WPC) to perform decorative functions together with structural function. Pigments are used in permanent coloring of concrete with colors different from the natural color of the cement or the aggregates with mixing WPC. In this study, an artificial neural networks study was carried out to predict the color evaluation of black mortar using pigment and carbon black. A data set of a laboratory work, in which a total of 9 mortars were produced, was utilized in the Artificial Neural Networks (ANNs) study. The mortar mixture parameters were nine different pigment and carbon black ratios. Each mortar was measured at ten locations on the surface and averaged. Color can be evaluated by measurements of tristimulus values L* , a* and b* , represented in the chromatic space CIELAB. The L* value is a measure of luminosity (0 darkness), from completely opaque (0) to completely transparent (100); a* is a measure of redness (-a* greenness) and b* of yellowness (-b* blueness). ANN model is constructed, trained and tested using these data. The data used in the ANN model are arranged in a format of three input parameters that cover the pigment, carbon black and WPC and, an output parameter which is the color parameters of the black colored mortar. The results showed that ANN can be an alternative approach for the predicting the color parameters using mortar ingredients as input parameters.

Using cystoscopy to segment bladder tumors with a multivariate approach in different color spaces.

PubMed

Freitas, Nuno R; Vieira, Pedro M; Lima, Estevao; Lima, Carlos S

2017-07-01

Nowadays the diagnosis of bladder lesions relies upon cystoscopy examination and depends on the interpreter's experience. State of the art of bladder tumor identification are based on 3D reconstruction, using CT images (Virtual Cystoscopy) or images where the structures are exalted with the use of pigmentation, but none uses white light cystoscopy images. An initial attempt to automatically identify tumoral tissue was already developed by the authors and this paper will develop this idea. Traditional cystoscopy images processing has a huge potential to improve early tumor detection and allows a more effective treatment. In this paper is described a multivariate approach to do segmentation of bladder cystoscopy images, that will be used to automatically detect and improve physician diagnose. Each region can be assumed as a normal distribution with specific parameters, leading to the assumption that the distribution of intensities is a Gaussian Mixture Model (GMM). Region of high grade and low grade tumors, usually appears with higher intensity than normal regions. This paper proposes a Maximum a Posteriori (MAP) approach based on pixel intensities read simultaneously in different color channels from RGB, HSV and CIELab color spaces. The Expectation-Maximization (EM) algorithm is used to estimate the best multivariate GMM parameters. Experimental results show that the proposed method does bladder tumor segmentation into two classes in a more efficient way in RGB even in cases where the tumor shape is not well defined. Results also show that the elimination of component L from CIELab color space does not allow definition of the tumor shape.

Micro-Expression Recognition Using Color Spaces.

PubMed

Wang, Su-Jing; Yan, Wen-Jing; Li, Xiaobai; Zhao, Guoying; Zhou, Chun-Guang; Fu, Xiaolan; Yang, Minghao; Tao, Jianhua

2015-12-01

Micro-expressions are brief involuntary facial expressions that reveal genuine emotions and, thus, help detect lies. Because of their many promising applications, they have attracted the attention of researchers from various fields. Recent research reveals that two perceptual color spaces (CIELab and CIELuv) provide useful information for expression recognition. This paper is an extended version of our International Conference on Pattern Recognition paper, in which we propose a novel color space model, tensor independent color space (TICS), to help recognize micro-expressions. In this paper, we further show that CIELab and CIELuv are also helpful in recognizing micro-expressions, and we indicate why these three color spaces achieve better performance. A micro-expression color video clip is treated as a fourth-order tensor, i.e., a four-dimension array. The first two dimensions are the spatial information, the third is the temporal information, and the fourth is the color information. We transform the fourth dimension from RGB into TICS, in which the color components are as independent as possible. The combination of dynamic texture and independent color components achieves a higher accuracy than does that of RGB. In addition, we define a set of regions of interests (ROIs) based on the facial action coding system and calculated the dynamic texture histograms for each ROI. Experiments are conducted on two micro-expression databases, CASME and CASME 2, and the results show that the performances for TICS, CIELab, and CIELuv are better than those for RGB or gray.

Computation and visualization of the MacAdam limits for any lightness, hue angle, and light source

NASA Astrophysics Data System (ADS)

Martínez-Verdú, Francisco; Perales, Esther; Chorro, Elisabet; de Fez, Dolores; Viqueira, Valentín; Gilabert, Eduardo

2007-06-01

We present a systematic algorithm capable of searching for optimal colors for any lightness L* (between 0 and 100), any illuminant (D65, F2, F7, F11, etc.), and any light source reported by CIE. Color solids are graphed in some color spaces (CIELAB, SVF, DIN99d, and CIECAM02) by horizontal (constant lightness) and transversal (constant hue angle) sections. Color solids plotted in DIN99d and CIECAM02 color spaces look more spherical or homogeneous than the ones plotted in CIELAB and SVF color spaces. Depending on the spectrum of the light source or illuminant, the shape of its color solid and its content (variety of distinguishable colors, with or without color correspondence) change drastically, particularly with sources whose spectrum is discontinuous and/or very peaked, with correlated color temperature lower than 5500 K. This could be used to propose an absolute colorimetric quality index for light sources comparing the volumes of their gamuts, in a uniform color space.

A color gamut description algorithm for liquid crystal displays in CIELAB space.

PubMed

Sun, Bangyong; Liu, Han; Li, Wenli; Zhou, Shisheng

2014-01-01

Because the accuracy of gamut boundary description is significant for gamut mapping process, a gamut boundary calculating method for LCD monitors is proposed in this paper. Within most of the previous gamut boundary calculation algorithms, the gamut boundary is calculated in CIELAB space directly, and part of inside-gamut points are mistaken for the boundary points. While, in the new proposed algorithm, the points on the surface of RGB cube are selected as the boundary points, and then converted and described in CIELAB color space. Thus, in our algorithm, the true gamut boundary points are found and a more accurate gamut boundary is described. In experiment, a Toshiba LCD monitor's 3D CIELAB gamut for evaluation is firstly described which has regular-shaped outer surface, and then two 2D gamut boundaries ( CIE-a*b* boundary and CIE-C*L* boundary) are calculated which are often used in gamut mapping process. When our algorithm is compared with several famous gamut calculating algorithms, the gamut volumes are very close, which indicates that our algorithm's accuracy is precise and acceptable.

A Color Gamut Description Algorithm for Liquid Crystal Displays in CIELAB Space

PubMed Central

Sun, Bangyong; Liu, Han; Li, Wenli; Zhou, Shisheng

2014-01-01

Because the accuracy of gamut boundary description is significant for gamut mapping process, a gamut boundary calculating method for LCD monitors is proposed in this paper. Within most of the previous gamut boundary calculation algorithms, the gamut boundary is calculated in CIELAB space directly, and part of inside-gamut points are mistaken for the boundary points. While, in the new proposed algorithm, the points on the surface of RGB cube are selected as the boundary points, and then converted and described in CIELAB color space. Thus, in our algorithm, the true gamut boundary points are found and a more accurate gamut boundary is described. In experiment, a Toshiba LCD monitor's 3D CIELAB gamut for evaluation is firstly described which has regular-shaped outer surface, and then two 2D gamut boundaries ( CIE-a*b* boundary and CIE-C*L* boundary) are calculated which are often used in gamut mapping process. When our algorithm is compared with several famous gamut calculating algorithms, the gamut volumes are very close, which indicates that our algorithm's accuracy is precise and acceptable. PMID:24892068

A device for the color measurement and detection of spots on the skin.

PubMed

Pladellorens, Josep; Pintó, Agustí; Segura, Jordi; Cadevall, Cristina; Antó, Joan; Pujol, Jaume; Vilaseca, Meritxell; Coll, Joaquín

2008-02-01

In this work, we present a new and fast easy-to-use device that allows the measurement of color and the detection of spots on the human skin. The developed device is highly practical for relatively untrained operators and uses inexpensive consumer equipment, such as a CCD color camera, a light source composed of LEDs and a laptop. The knowledge of the color of the skin and the detection of spots can be useful in several areas such as in dermatology applications, the cosmetics industry, the biometrics field, health care, etc. In order to perform these measurements the system takes a picture of the skin. After that, the operator selects the region of the skin to be analyzed on the displayed image and the system provides the CIELAB color coordinates, the chroma and the ITA parameter (Individual Tipology Angle), allowing the comparison with other reference images by means of CIELAB color differences. The system also detects spots, such as freckles, age spots, sunspots, pimples, black heads, etc., in a determined region, allowing the objective measurement of their size and area. The colorimetric information provided by a conventional spectrophotometer for the tested samples and the computed values obtained with the new developed system are quite similar, meaning that the developed system can be used to perform color measurements with relatively high accuracy. On the other hand, the feasibility of the system in order to detect and measure spots on the human skin has also been checked over a great amount of images, obtaining results with high precision. In this work, we present a new system that may be very useful in order to measure the color and to detect spots of the skin. Its portability and easy applicability will be very useful in dermatologic and cosmetic studies.

Evaluating the uniformity of color spaces and performance of color difference formulae

NASA Astrophysics Data System (ADS)

Lian, Yusheng; Liao, Ningfang; Wang, Jiajia; Tan, Boneng; Liu, Zilong

2010-11-01

Using small color difference data sets (Macadam ellipses dataset and RIT-DuPont suprathreshold color difference ellipses dataset), and large color difference data sets (Munsell Renovation Data and OSA Uniform Color Scales dataset), the uniformity of several color spaces and performance of color difference formulae based on these color spaces are evaluated. The color spaces used are CIELAB, DIN99d, IPT, and CIECAM02-UCS. It is found that the uniformity of lightness is better than saturation and hue. Overall, for all these color spaces, the uniformity in the blue area is inferior to the other area. The uniformity of CIECAM02-UCS is superior to the other color spaces for the whole color-difference range from small to large. The uniformity of CIELAB and IPT for the large color difference data sets is better than it for the small color difference data sets, but the DIN99d is opposite. Two common performance factors (PF/3 and STRESS) and the statistical F-test are calculated to test the performance of color difference formula. The results show that the performance of color difference formulae based on these four color spaces is consistent with the uniformity of these color spaces.

Color Differences Between Pink Veneering Ceramics and the Human Gingiva.

PubMed

Valente, Nicola Alberto; Sailer, Irena; Fehmer, Vincent; Thoma, Daniel Stefan

2018-06-12

The aim of this study was to examine 10 different shades of pink ceramic to determine which one best matches the mean color of human gingiva. Bar-shaped zirconia samples were fabricated and veneered with 1 of 10 pink zirconia veneering ceramics. The color of the gingiva at the central maxillary incisors of 20 healthy volunteers was compared to the pink veneering ceramics using a spectrophotometer (Spectroshade, MHT). The obtained color parameters L*, a*, and b* (CIELAB) of the gingiva and the ceramics were used to calculate the color difference (ΔE). Mean ΔE values were descriptively analyzed and compared to the threshold value for visibility of color differences of gingiva (ΔE = 3.1). The lowest pink ceramic ΔE value obtained (closest to the mean ΔE of all the volunteers' gingiva) was 6.2. All the tested ceramics exhibited a color difference above the threshold value for visibility.

Human visual system-based color image steganography using the contourlet transform

NASA Astrophysics Data System (ADS)

Abdul, W.; Carré, P.; Gaborit, P.

2010-01-01

We present a steganographic scheme based on the contourlet transform which uses the contrast sensitivity function (CSF) to control the force of insertion of the hidden information in a perceptually uniform color space. The CIELAB color space is used as it is well suited for steganographic applications because any change in the CIELAB color space has a corresponding effect on the human visual system as is very important for steganographic schemes to be undetectable by the human visual system (HVS). The perceptual decomposition of the contourlet transform gives it a natural advantage over other decompositions as it can be molded with respect to the human perception of different frequencies in an image. The evaluation of the imperceptibility of the steganographic scheme with respect to the color perception of the HVS is done using standard methods such as the structural similarity (SSIM) and CIEDE2000. The robustness of the inserted watermark is tested against JPEG compression.

Utilizing typical color appearance models to represent perceptual brightness and colorfulness for digital images

NASA Astrophysics Data System (ADS)

Gong, Rui; Wang, Qing; Shao, Xiaopeng; Zhou, Conghao

2016-12-01

This study aims to expand the applications of color appearance models to representing the perceptual attributes for digital images, which supplies more accurate methods for predicting image brightness and image colorfulness. Two typical models, i.e., the CIELAB model and the CIECAM02, were involved in developing algorithms to predict brightness and colorfulness for various images, in which three methods were designed to handle pixels of different color contents. Moreover, massive visual data were collected from psychophysical experiments on two mobile displays under three lighting conditions to analyze the characteristics of visual perception on these two attributes and to test the prediction accuracy of each algorithm. Afterward, detailed analyses revealed that image brightness and image colorfulness were predicted well by calculating the CIECAM02 parameters of lightness and chroma; thus, the suitable methods for dealing with different color pixels were determined for image brightness and image colorfulness, respectively. This study supplies an example of enlarging color appearance models to describe image perception.

Evaluation of polymerization-dependent changes in color and translucency of resin composites using two formulae.

PubMed

Paravina, Rade D; Kimura, Mikio; Powers, John M

2005-09-01

The aim of this study was to evaluate polymerization-dependent changes in the color and translucency parameter (TP) of resin composites and to compare results obtained using two color-difference metric formulae, CIELAB and CIEDE 2000. Twenty-eight shades of commercial resin composites were analyzed. Specimens (n = 5) were made as discs, 11 mm in diameter and 2-mm thick, using cylindrical molds. Data were collected before and after composite polymerization, using a spectrophotometer. In regard to in vitro color changes of composites (DeltaE*) a DeltaE76 of 3.7 or greater was considered to be an unacceptable color change. Data were analyzed by analysis of variance, and Fisher's protected least significant difference (PLSD) intervals for comparison of means were calculated at the 0.05 level of significance. Mean polymerization-dependent differences in color were DeltaE00 = 4.48 (2.11) and DeltaE76 = 5.51 (2.68). The DeltaTP00 range was 2.57, while the DeltaTP76 range was 2.89. Mean polymerization-dependent differences in translucency were DeltaTP00 = 0.84 (0.77) and DeltaTP76 = 0.87 (0.76). Analysis of variance showed significant differences among composites, shades, and their interactions (P < 0.0001; power = 1.0). Regression equations and r values for the two color-difference formulae and all evaluated TP values showed very strong correlation. In conclusion, within the limitations of this study, polymerization-dependent changes in color and translucency were highly varied. The majority of shades showed polymerization-dependent differences in color higher than the DeltaE76 = 3.7. The TP generally increased after light polymerization by light activation. The very strong correlation (r > 0.97) between the two color-difference formulae indicates that the limitations of the CIELAB system do not appear to be a problem when evaluating composites; however, recorded differences between DeltaE76 and DeltaE00 values stress the importance of data conversion.

Camouflage effects following resin infiltration of postorthodontic white-spot lesions in vivo: One-year follow-up.

PubMed

Eckstein, Amely; Helms, Hans-Joachim; Knösel, Michael

2015-05-01

To assess camouflage effects by concealment of postorthodontic white-spot lesions (WSLs) to sound adjacent enamel (SAE) achieved over 12 months with resin infiltration (Icon, DMG, Hamburg, Germany). Twenty subjects (trial teeth nteeth = 111) who had received resin infiltration treatment of noncavitated postorthodontic WSLs were contacted for a 1-year follow-up assessment of CIE-L*a*b* colors (T12). Color and lightness (CIE-L*a*b*) data for WSLs and SAE were compared to baseline data assessed before infiltration (T0) and those assessed after 6 months (T6), using a spectrophotometer. The target parameter was the difference between the summarized color and lightness values (ΔEWSL/SAE). Intergroup (WSL, SAE) and intertime comparisons (T0 vs T6, T12) were performed using paired t-tests at a significance level of α = 5%. Nine subjects (trial teeth nteeth = 49; male/female ratio 5/4; age range 13-19 years) were available at T12. After the highly significant reduction of ΔEWSL/SAE discrepancies between T0 and T6, analysis of 12-month records revealed color and lightness discrepancy of WSL vs SAE that was significantly decreased compared with baseline, indicating an assimilation of WSL color to SAE appearance after infiltration, while an additional reduction of discrepancies between T6 and T12 was not significant. As color and lightness characteristics of the Icon infiltrant as well as the esthetic camouflage effects achieved by WSL infiltration were not altered significantly or clinically relevant after 12 months, the method of resin infiltration can be recommended for an enduring esthetic improvement of postorthodontic WSL.

Perceptual Color Characterization of Cameras

PubMed Central

Vazquez-Corral, Javier; Connah, David; Bertalmío, Marcelo

2014-01-01

Color camera characterization, mapping outputs from the camera sensors to an independent color space, such as XY Z, is an important step in the camera processing pipeline. Until now, this procedure has been primarily solved by using a 3 × 3 matrix obtained via a least-squares optimization. In this paper, we propose to use the spherical sampling method, recently published by Finlayson et al., to perform a perceptual color characterization. In particular, we search for the 3 × 3 matrix that minimizes three different perceptual errors, one pixel based and two spatially based. For the pixel-based case, we minimize the CIE ΔE error, while for the spatial-based case, we minimize both the S-CIELAB error and the CID error measure. Our results demonstrate an improvement of approximately 3% for the ΔE error, 7% for the S-CIELAB error and 13% for the CID error measures. PMID:25490586

Application of tristimulus colorimetry to estimate the carotenoids content in ultrafrozen orange juices.

PubMed

Meléndez-Martínez, Antonio J; Vicario, Isabel M; Heredia, Francisco J

2003-12-03

Tristimulus Colorimetry was applied to characterize the color of Valencia late orange juices. Color measurements were made against white background and black background. The profile of the main carotenoids related to the color of the juices was determined by HPLC. Significant correlations (p < 0.05) between b*, Cab* and h(ab) and the content of beta-cryptoxanthin, lutein + zeaxanthin and beta-carotene were found. The correlations between the color parameters L*, a*, b*, Cab* and h(ab) and the carotenoids content were also explored by partial least squares. The results obtained have shown that it is possible to obtain equations, by means of multiple regression models, which allow the determination of the individual carotenoid levels from the CIELAB color parameters, with R2 values always over 0.9. In this sense, equations have been proposed to calculate the retinol equivalents (1 RE = 1 microgram retinol = 12 micrograms beta-carotene = 24 micrograms alpha-carotene = 24 micrograms beta-cryptoxanthin) of the orange juice analyzed as a function of the color parameters calculated from measurement made against white and black backgrounds. The average RE per liter of juice obtained by HPLC was 51.07 +/- 18.89, whereas employing these equations, average RE values obtained were 51.16 +/- 1.36 and 51.21 +/- 1.70 for white background and black background, respectively.

Color stabilization of porcine hemoglobin during spray-drying and powder storage by combining chelating and reducing agents.

PubMed

Salvador, P; Toldrà, M; Parés, D; Carretero, C; Saguer, E

2009-10-01

This work focuses on the effects of adding a chelating agent - such as nicotinic acid (NA, 2% w/v) or nicotinamide (Nam, 2.5% w/v) - along with glucose as a reducing agent (G, 10% w/v) to fresh porcine hemoglobin in order to stabilize its red color during spray-drying and powder storage at room temperature. Correlations between the CIELAB color parameters and the relative percentages of the different hemoglobin derivatives (liganded and deliganded ferrohemoglobin, and methemoglobin) were analyzed. The results indicate that, although little effects could be observed for any of the combined treatments on fresh hemoglobin, they were effective against pigment autoxidation during dehydration and subsequent storage. From the results, it can also be concluded that glucose was the main contributor to the color stabilization of the hemoglobin powder, probably due to its high water retention capacity.

Color stabilization of red wines. A chemical and colloidal approach.

PubMed

Alcalde-Eon, Cristina; García-Estévez, Ignacio; Puente, Victor; Rivas-Gonzalo, Julián C; Escribano-Bailón, M Teresa

2014-07-23

The effects of cold treatment and time on CIELAB color parameters and on anthocyanin and anthocyanin-derived pigments composition have been evaluated as has been the effectiveness of either an enological tannin or a mannoprotein (M) on their stabilization. With respect to color, hue (hab) was increased in the wines treated with both enological products. Furthermore, the color changes induced by cold treatment were lessened by the addition of these two enological products, although the protective effect was higher for the wines treated with M. The pigment analysis revealed higher percentages of anthocyanin-derived pigments in tannin and M-treated samples (in both cold treated and not) in relation to control ones. The addition of the enological tannin may favor the synthesis of anthocyanin-derived pigments, which are chemically more stable than native anthocyanins, whereas M seems to stabilize anthocyanin-derived pigments from a colloidal point of view, avoiding their aggregation and further precipitation.

The Application of Support Vector Machine (svm) Using Cielab Color Model, Color Intensity and Color Constancy as Features for Ortho Image Classification of Benthic Habitats in Hinatuan, Surigao del Sur, Philippines

NASA Astrophysics Data System (ADS)

Cubillas, J. E.; Japitana, M.

2016-06-01

This study demonstrates the application of CIELAB, Color intensity, and One Dimensional Scalar Constancy as features for image recognition and classifying benthic habitats in an image with the coastal areas of Hinatuan, Surigao Del Sur, Philippines as the study area. The study area is composed of four datasets, namely: (a) Blk66L005, (b) Blk66L021, (c) Blk66L024, and (d) Blk66L0114. SVM optimization was performed in Matlab® software with the help of Parallel Computing Toolbox to hasten the SVM computing speed. The image used for collecting samples for SVM procedure was Blk66L0114 in which a total of 134,516 sample objects of mangrove, possible coral existence with rocks, sand, sea, fish pens and sea grasses were collected and processed. The collected samples were then used as training sets for the supervised learning algorithm and for the creation of class definitions. The learned hyper-planes separating one class from another in the multi-dimensional feature space can be thought of as a super feature which will then be used in developing the C (classifier) rule set in eCognition® software. The classification results of the sampling site yielded an accuracy of 98.85% which confirms the reliability of remote sensing techniques and analysis employed to orthophotos like the CIELAB, Color Intensity and One dimensional scalar constancy and the use of SVM classification algorithm in classifying benthic habitats.

Heat-induced chemical and color changes of extractive-free Black Locust (Rosinia Pseudoacacia) wood

Treesearch

Yao Chen; Jianmin Gao; Yongming Fan; Mandla A. Tshabalala; Nicole M. Stark

2012-01-01

To investigate chemical and color changes of the polymeric constituents of black locust (Robinia pseudoacacia) wood during heat treatment, extractive-free wood flour was conditioned to 30% initial moisture content (MC) and heated for 24 h at 120 °C in either an oxygen or nitrogen atmosphere. The color change was measured using the CIELAB color system. Chemical changes...

Designing a Practical System for Spectral Imaging of Skylight

DTIC Science & Technology

2005-09-20

Commission Interna- tionale de l’Éclairage), include CIELUV , CIELAB , CIE94, and CIEDE2000.21,22 These metrics quantify distances in their respective...thresholds for RMSE and CIEDE2000 metrics when searching for optimum sensors; Hernández-Andrés et al.1 used GFC, CIELUV , and IIE(%) in a similar way. As...once. We use GFC as a spectral metric, CIELAB as a col- orimetric cost function (denoted by E*ab, the dis- tance between two colors in the CIE’s uniform

Effects of Copper Pollution on the Phenolic Compound Content, Color, and Antioxidant Activity of Wine.

PubMed

Sun, Xiangyu; Ma, Tingting; Han, Luyang; Huang, Weidong; Zhan, Jicheng

2017-05-03

The effects of copper pollution on the polyphenol content, color, and antioxidant activity of wine, as well as correlations among these factors, were investigated. Copper had clear influences on wine polyphenol content. At low copper concentrations, the concentrations of nearly all polyphenols increased, and the antioxidant activity values of the wine also increased. When the copper concentration reached the lowest level of the medium copper range (9.6~16 mg/L), most of the indices also improved. When the copper concentrations reached the latter part of the medium copper range (19.2 and 22.4 mg/L), many of the tested indices began to decrease. Furthermore, when the copper concentration reached the high ranges (32, 64, and 96 mg/L), the polyphenol content, CIELAB color parameters, and antioxidant activity of wine were substantially decreased, indicating the need to control increasing copper content in grape must.

Super-Resolution for Color Imagery

DTIC Science & Technology

2017-09-01

separately; however, it requires performing the super-resolution computation 3 times. We transform images in the default red, green, blue (RGB) color space...chrominance components based on ARL’s alias-free image upsampling using Fourier-based windowing methods. A reverse transformation is performed on... Transformation from sRGB to CIELAB............................................... 3 Fig. 2 YCbCr mathematical coordinate transformation

Discrimination of Clover and Citrus Honeys from Egypt According to Floral Type Using Easily Assessable Physicochemical Parameters and Discriminant Analysis: An External Validation of the Chemometric Approach.

PubMed

Karabagias, Ioannis K; Karabournioti, Sofia

2018-05-03

Twenty-two honey samples, namely clover and citrus honeys, were collected from the greater Cairo area during the harvesting year 2014⁻2015. The main purpose of the present study was to characterize the aforementioned honey types and to investigate whether the use of easily assessable physicochemical parameters, including color attributes in combination with chemometrics, could differentiate honey floral origin. Parameters taken into account were: pH, electrical conductivity, ash, free acidity, lactonic acidity, total acidity, moisture content, total sugars (degrees Brix-°Bx), total dissolved solids and their ratio to total acidity, salinity, CIELAB color parameters, along with browning index values. Results showed that all honey samples analyzed met the European quality standards set for honey and had variations in the aforementioned physicochemical parameters depending on floral origin. Application of linear discriminant analysis showed that eight physicochemical parameters, including color, could classify Egyptian honeys according to floral origin ( p < 0.05). Correct classification rate was 95.5% using the original method and 90.9% using the cross validation method. The discriminatory ability of the developed model was further validated using unknown honey samples. The overall correct classification rate was not affected. Specific physicochemical parameter analysis in combination with chemometrics has the potential to enhance the differences in floral honeys produced in a given geographical zone.

Discrimination of Clover and Citrus Honeys from Egypt According to Floral Type Using Easily Assessable Physicochemical Parameters and Discriminant Analysis: An External Validation of the Chemometric Approach

PubMed Central

Karabournioti, Sofia

2018-01-01

Twenty-two honey samples, namely clover and citrus honeys, were collected from the greater Cairo area during the harvesting year 2014–2015. The main purpose of the present study was to characterize the aforementioned honey types and to investigate whether the use of easily assessable physicochemical parameters, including color attributes in combination with chemometrics, could differentiate honey floral origin. Parameters taken into account were: pH, electrical conductivity, ash, free acidity, lactonic acidity, total acidity, moisture content, total sugars (degrees Brix-°Bx), total dissolved solids and their ratio to total acidity, salinity, CIELAB color parameters, along with browning index values. Results showed that all honey samples analyzed met the European quality standards set for honey and had variations in the aforementioned physicochemical parameters depending on floral origin. Application of linear discriminant analysis showed that eight physicochemical parameters, including color, could classify Egyptian honeys according to floral origin (p < 0.05). Correct classification rate was 95.5% using the original method and 90.9% using the cross validation method. The discriminatory ability of the developed model was further validated using unknown honey samples. The overall correct classification rate was not affected. Specific physicochemical parameter analysis in combination with chemometrics has the potential to enhance the differences in floral honeys produced in a given geographical zone. PMID:29751543

Estimating the color of maxillary central incisors based on age and gender

PubMed Central

Gozalo-Diaz, David; Johnston, William M.; Wee, Alvin G.

2008-01-01

Statement of problem There is no scientific information regarding the selection of the color of teeth for edentulous patients. Purpose The purpose of this study was to evaluate linear regression models that may be used to predict color parameters for central incisors of edentulous patients based on some characteristics of dentate subjects. Material and methods A spectroradiometer and an external light source were set in a noncontacting 45/0 degree (45-degree illumination and 0-degree observer) optical configuration to measure the color of subjects’ vital craniofacial structures (maxillary central incisor, attached gingiva, and facial skin). The subjects (n=120) were stratified into 5 age groups with 4 racial groups and balanced for gender. Linear first-order regression was used to determine the significant factors (α=.05) in the prediction model for each color direction of the color of the maxillary central incisor. Age, gender, and color of the other craniofacial structures were studied as potential predictors. Final predictions in each color direction were based only on the statistically significant factors, and then the color differences between observed and predicted CIELAB values for the central incisors were calculated and summarized. Results The statistically significant predictors of age and gender accounted for 36% of the total variability in L*. The statistically significant predictor of age accounted for 16% of the total variability in a*. The statistically significant predictors of age and gender accounted for 21% of the variability in b*. The mean ΔE (SD) between predicted and observed CIELAB values for the central incisor was 5.8 (3.2). Conclusions Age and gender were found to be statistically significant determinants in predicting the natural color of central incisors. Although the precision of these predictions was less than the median color difference found for all pairs of teeth studied, and may be considered an acceptable precision, further study is needed to reduce this precision to the limit of detection. Clinical Implications Age is highly correlated with the natural color of the central incisors. When age increases, the central incisor becomes darker, more reddish, and more yellow. Also, the women subjects in this study had lighter and less yellow central incisors than the men. PMID:18672125

Technical note: quantitative measures of iris color using high resolution photographs.

PubMed

Edwards, Melissa; Gozdzik, Agnes; Ross, Kendra; Miles, Jon; Parra, Esteban J

2012-01-01

Our understanding of the genetic architecture of iris color is still limited. This is partly related to difficulties associated with obtaining quantitative measurements of eye color. Here we introduce a new automated method for measuring iris color using high resolution photographs. This method extracts color measurements in the CIE 1976 L*a*b* (CIELAB) color space from a 256 by 256 pixel square sampled from the 9:00 meridian of the iris. Color is defined across three dimensions: L* (the lightness coordinate), a* (the red-green coordinate), and b* (the blue-yellow coordinate). We applied this method to a sample of individuals of diverse ancestry (East Asian, European and South Asian) that was genotyped for the HERC2 rs12913832 polymorphism, which is strongly associated with blue eye color. We identified substantial variation in the CIELAB color space, not only in the European sample, but also in the East Asian and South Asian samples. As expected, rs12913832 was significantly associated with quantitative iris color measurements in subjects of European ancestry. However, this SNP was also strongly associated with iris color in the South Asian sample, although there were no participants with blue irides in this sample. The usefulness of this method is not restricted only to the study of iris pigmentation. High-resolution pictures of the iris will also make it possible to study the genetic variation involved in iris textural patterns, which show substantial heritability in human populations. Copyright © 2011 Wiley Periodicals, Inc.

Colorimetric characterization of digital cameras with unrestricted capture settings applicable for different illumination circumstances

NASA Astrophysics Data System (ADS)

Fang, Jingyu; Xu, Haisong; Wang, Zhehong; Wu, Xiaomin

2016-05-01

With colorimetric characterization, digital cameras can be used as image-based tristimulus colorimeters for color communication. In order to overcome the restriction of fixed capture settings adopted in the conventional colorimetric characterization procedures, a novel method was proposed considering capture settings. The method calculating colorimetric value of the measured image contains five main steps, including conversion from RGB values to equivalent ones of training settings through factors based on imaging system model so as to build the bridge between different settings, scaling factors involved in preparation steps for transformation mapping to avoid errors resulted from nonlinearity of polynomial mapping for different ranges of illumination levels. The experiment results indicate that the prediction error of the proposed method, which was measured by CIELAB color difference formula, reaches less than 2 CIELAB units under different illumination levels and different correlated color temperatures. This prediction accuracy for different capture settings remains the same level as the conventional method for particular lighting condition.

Lightness, chroma and hue differences on visual shade matching.

PubMed

Pecho, Oscar E; Pérez, María M; Ghinea, Razvan; Della Bona, Alvaro

2016-11-01

To analyze the influence of lightness, chroma and hue differences on visual shade matching performed by dental students. 100 dental students (DS) volunteers with normal vision participated in the study. A spectroradiometer (SP) was used to measure the spectral reflectance of 4 extracted human upper central incisors (UCI 1-4) and shade tabs from Vita Classical (VC) and Vita Toothguide 3D-Master (3D) shade guides. Measurements were performed over a gray background, inside a viewing booth and under D65 illuminant (diffuse/0° geometry). Color parameters (L*, a*, b*, C* and h°) were calculated. DS used VC and 3D to visually select the best shade match for each UCI. CIE metric differences (Δa * ,Δb * ,ΔL ' , ΔC ' and ΔH ' ) and CIEDE2000(2:1:1) lightness (ΔE L ), chroma (ΔE C ) and hue (ΔE H ) differences were obtained from each UCI and the first three shades selected by DS and the first option using CIELAB, CIEDE2000(1:1:1) and CIEDE2000(2:1:1) color difference metrics. The closest CIELAB color-discrimination ellipsoid (from RIT-DuPont visual color-difference data) to each UCI was selected for the analysis of visual shade matching. DS showed a preference for shades with lower chroma (ΔC ' and ΔE C ) and/or hue (ΔH ' and ΔE H ) values instead of shades with lower lightness values (ΔL ' and ΔE L ). Most best visual matches were near the tolerance ellipsoid centered on tooth shade. This study is an attempt to partially explain the inconsistencies between visual and instrumental shade matching and the limitations of shade guides. Visual shade matching was driven by color differences with lower chroma and hue values. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Comparative Thermal Degradation Patterns of Natural Yellow Colorants Used in Foods.

PubMed

Giménez, Pedro J; Fernández-López, José A; Angosto, José M; Obón, José M

2015-12-01

There is a great interest in natural yellow colorants due to warnings issued about certain yellow food colorings of synthetic origin. However, no comparative studies have been reported of their thermal stability. For this reason, the thermal stabilities of six natural yellow colorants used in foods--lutein, riboflavin, curcumin, ß-carotene, gardenia yellow and Opuntia betaxanthins--were studied in simple solutions over a temperature range 30-90 °C. Spectral properties and visual color were investigated during 6 h of heat treatment. Visual color was monitored from the CIEL*a*b* parameters. The remaining absorbance at maximum wavelength and the total color difference were used to quantify color degradation. The rate of color degradation increased as the temperature rose. The results showed that the thermal degradation of the colorants followed a first-order reaction kinetics. The reaction rate constants and half-life periods were determined as being central to understanding the color degradation kinetics. The temperature-dependent degradation was adequately modeled on the Arrhenius equation. Activation energies ranged from 3.2 kJmol(-1) (lutein) to 43.7 kJmol(-1) (Opuntia betaxanthins). ß-carotene and lutein exhibited high thermal stability, while betaxanthins and riboflavin degraded rapidly as temperature increased. Gardenia yellow and curcumin were in an intermediate position.

Iron Compounds and the Color of Soils in the Sakhalin Island

NASA Astrophysics Data System (ADS)

Vodyanitskii, Yu. N.; Kirillova, N. P.; Manakhov, D. V.; Karpukhin, M. M.

2018-02-01

Numerical parameters of soil color were studied according to the CIE-L*a*b color system before and after the Tamm's and Mehra-Jackson's treatments; we also determined the total Fe content in the samples from the main genetic horizons of the alluvial gray-humus soil, two profiles of burozems, and two profiles of podzols in the Sakhalin Island. In the analyzed samples, the numerical color parameters L* (lightness), a* (redness) and b* (yellowness) are found to vary within 46-73, 3-11, and 8-28, respectively. A linear relationship is revealed between the numerical values of a* parameters and Fe content in the Mehra-Jackson extracts; the regression equations are derived with the determination coefficients ( R 2): 0.49 (typical burozem), 0.79 (podzolized burozem), 0.96 (shallow-podzolic mucky podzol), 0.98 (gray-humus gley alluvial soil). For the surface-podzolic mucky podzol contaminated with petroleum hydrocarbons, R 2 was equal to only 0.03. In the gray humus (AY) and structural-metamorphic (BM) horizons of the studied soils, a* and b* parameters decrease after their treatment with the Tamm's reagent by 2 points on average. After the Mehra-Jackson treatment, the a* parameter decreased by 6 (AY) and 8 (BM) points; whereas b* parameter, by 10 and 15 points, respectively. In the E horizons of podzols, the Tamm's treatment increased a* and b* parameters by 1 point; whereas the Mehra-Jackson's treatment decreased these parameters by only 1 and 3 points, respectively. The redness (a*) decreased maximally in the lower gley horizon of the alluvial gray humus soil, i.e., by 6 (in the Tamm's extract) and 10 points (in the Mehra-Jackson's) extract. Yellowness (b*) decreased by 12 and 17 points, respectively. The revealed color specifics in the untreated samples and the color transformation under the impact of reagents in the studied soils and horizons may serve as an additional parameter that characterizes quantitatively the object of investigation in the reference databases.

Color universal design: analysis of color category dependency on color vision type (3)

NASA Astrophysics Data System (ADS)

Kojima, Natsuki; Ichihara, Yasuyo G.; Ikeda, Tomohiro; Kamachi, Miyuki G.; Ito, Kei

2012-01-01

We report on the results of a study investigating the color perception characteristics of people with red-green color confusion. We believe that this is an important step towards achieving Color Universal Design. In Japan, approximately 5% of men and 0.2% of women have red-green confusion. The percentage for men is higher in Europe and the United States; up to 8% in some countries. Red-green confusion involves a perception of colors different from normal color vision. Colors are used as a means of disseminating clear information to people; however, it may be difficult to convey the correct information to people who have red-green confusion. Consequently, colors should be chosen that minimize accidents and that promote more effective communication. In a previous survey, we investigated color categories common to each color vision type, trichromat (C-type color vision), protan (P-type color vision) and deuteran (D-type color vision). In the present study, first, we conducted experiments in order to verify a previous survey of C-type color vision and P-type color vision. Next, we investigated color difference levels within "CIE 1976 L*a*b*" (the CIELAB uniform color space), where neither C-type nor P-type color vision causes accidents under certain conditions (rain maps/contour line levels and graph color legend levels). As a result, we propose a common chromaticity of colors that the two color vision types are able to categorize by means of color names common to C-type color vision. We also offer a proposal to explain perception characteristics of color differences with normal color vision and red-green confusion using the CIELAB uniform color space. This report is a follow-up to SPIE-IS & T / Vol. 7528 7528051-8 and SPIE-IS & T /vol. 7866 78660J-1-8.

[Precision and accuracy of a dental spectrophotometer in gingival color measurement of maxillary anterior gingival].

PubMed

Du, Yang; Tan, Jian-guo; Chen, Li; Wang, Fang-ping; Tan, Yao; Zhou, Jian-feng

2012-08-18

To explore a gingival shade matching method and to evaluate the precision and accuracy of a dental spectrophotometer modified to be used in gingival color measurement. Crystaleye, a dental spectrophotometer (Olympus, Tokyo, Japan) with a custom shading cover was tested. For precision assessment, two experienced experimenters measured anterior maxillary incisors five times for each tooth. A total of 20 healthy gingival sites (attached gingiva, free gingiva and medial gingival papilla in anterior maxillary region) were measured,the Commission Internationale de I' Eclairage (CIE) color parameters (CIE L*a*b*) of which were analyzed using the supporting software. For accuracy assessment, a rectangular area of approximately 3 mm×3 mm was chosen in the attached gingival portion for spectral analysis. PR715 (SpectraScan;Photo Research Inc.,California, USA), a spectroradiometer, was utilized as standard control. Average color differences (ΔE) between the values from PR715 and Crystaleye were calculated. In precision assessment,ΔL* between the values in all the test sites and average values were from(0.28±0.16)to(0.78±0.57), with Δa*and Δb* from(0.28±0.15)to (0.87±0.65),from(0.19±0.09)to( 0.58±0.78), respectively. Average ΔE between values in all test sites and average values were from (0.62 ± 0.17) to (1.25 ± 0.98) CIELAB units, with a total average ΔE(0.90 ± 0.18). In accuracy assessment, ΔL* with control device were from(0.58±0.50)to(2.22±1.89),with Δa*and Δb* from(1.03±0.67)to(2.99±1.32),from(0.68±0.78)to(1.26±0.83), respectively. Average ΔE with the control device were from (2.44±0.82) to (3.51±1.03) CIELAB units, with a total average ΔE (2.96 ± 1.08). With appropriate modification, Crystaleye, the spectrophotometer, has demonstrated relative minor color variations that can be useful in gingival color measurement.

Associations among Protein Biomarkers and pH and Color Traits in Longissimus thoracis and Rectus abdominis Muscles in Protected Designation of Origin Maine-Anjou Cull Cows.

PubMed

Gagaoua, Mohammed; Couvreur, Sébastien; Le Bec, Guillain; Aminot, Ghislain; Picard, Brigitte

2017-05-03

This study investigated the relationships among a list of 23 protein biomarkers with CIE-L*a*b* meat color traits and ultimate pH on Longissimus thoracis (LT) and Rectus abdominis (RA) muscles of 48 protected designation of origin Maine-Anjou cows. The technological parameters were correlated with several biomarkers and were in some cases muscle-dependent. More biomarkers were related to pHu in LT than in RA muscle. Some consistencies were found, by the common correlation of pHu with MyHC-IIa and MyHC-IIx. The pHu of the LT muscle was also correlated with other cytoskeletal entities and proteins belonging to metabolism and cellular stress. In contrast to the relationships found between biomarkers and LT pHu, more proteins were related to the instrumental color coordinates in RA than in LT muscle. The regression equations were parameter- and muscle-dependent. Certain of the retained proteins explained more than one color coordinate. Hsp70-Grp75 was positive in the models of L*, a*, b*, and C* of LT and of b* in the RA muscle. Further heat shock proteins were strongly related with the meat color coordinates in both muscles. The involvement of metabolic enzymes and myofibrillar proteins in the meat color development was also verified in this experiment. This study confirmed once again the importance of numerous biological pathways in beef color.

Effect of 2 Bleaching Agents with a Content of High Concentrated Hydrogen Peroxide on Stained 2 CAD/CAM Blocks and a Nanohybrid Composite Resin: An AFM Evaluation

PubMed Central

Cengiz, Esra

2017-01-01

The aim of this study was to evaluate color stability of 3 restorative materials, discoloration ability of different solutions, efficacy of 2 office bleaching agents, and surface roughness and topography. Sixty specimens for Clearfil Majesty Esthetic (CME), Lava Ultimate (LU), and Vita Enamic (VE) were prepared. They were immersed into 3 staining solutions for 2 weeks and then they were bleached. According to the measured L⁎, a⁎, and b⁎ parameters described by CIELAB system, color changes (ΔE00), translucency parameters (TP), whiteness index values (W⁎), and changes in closeness to pure white (ΔW⁎) were calculated. Then 3 specimens from each group were scanned with an atomic force microscope for surface analysis. After staining, CME groups and control groups of LU and VE showed clinically acceptable color changes (ΔE00 < 1,8). After bleaching, while a reverse effect on color was observed, VE showed the furthest color values to pure white. There was no statistically significant difference between whiteness index values of LU and CME. LU was the most translucent material during the study and TP values of materials showed minimal differences. Most of the VE groups and a control group of LU showed surface roughness (Ra) values higher than critical value for biofilm accumulation (0,2 μm). PMID:28804719

Indirect color prediction of amorphous carbohydrate melts as a function of thermal history.

PubMed

van Sleeuwen, Rutger M T; Gosse, Anaїck J; Normand, Valery

2013-07-01

Glassy carbohydrate microcapsules are widely used for the encapsulation of flavors in food applications, and are made using various thermal processes (for example, extrusion). During manufacturing, these carbohydrate melts are held at elevated temperatures and color can form due to nonenzymatic browning reactions. These reactions can negatively or positively affect the color and flavor of microcapsules. The rate of color formation of maltodextrin and maltodextrin/sucrose melts at elevated temperatures was determined spectrophotometrically and was found to follow pseudo zero-order kinetics. The effect of temperature was adequately modeled by an Arrhenius relationship. Reaction rate constants and Arrhenius parameters were determined for individual wavelengths in the visible range (360 to 700 nm at 1 nm intervals). Transient processes (temperature changes with time) were modeled as a sequence of small isothermal events, and the equivalent thermal history at a reference temperature calculated using the Arrhenius relationship. Therefore, spectral transmittance curves could be predicted with knowledge of the time/temperature relationship. Validation was conducted by subjecting both melts to a transient thermal history. Experimental transmittance spectrum compared favorably against predicted values. These spectra were optionally converted to any desirable color space (for example, CIELAB, XYZ, RGB) or derived parameter (for example, Browning Index). The tool could be used to better control nonenzymatic browning reactions in industrial food processes. © 2013 Institute of Food Technologists®

Comparisons of sensory descriptive flavor and texture profiles of cooked broiler breast fillets categorized by raw meat color lightness values

USDA-ARS?s Scientific Manuscript database

Three replicate trials were conducted to compare sensory descriptive profiles of cooked broiler breast fillets categorized by raw meat color lightness or CIELAB L* values (L*). In each trial, 20 light, 20 dark and 30 random fillets (42d old birds and deboned at 6-8h postmortem) were obtained from a...

LICA AstroCalc, a software to analyze the impact of artificial light: Extracting parameters from the spectra of street and indoor lamps

NASA Astrophysics Data System (ADS)

Ayuga, Carlos Eugenio Tapia; Zamorano, Jaime

2018-07-01

The night sky spectra of light-polluted areas is the result of the artificial light scattered back from the atmosphere and the reemission of the light after reflections in painted surfaces. This emission comes mainly from street and decorative lamps. We have built an extensive database of lamps spectra covering from UV to near IR and the software needed to analyze them. We describe the LICA-AstroCalc free software that is a user friendly GUI tool to extract information from our database spectra or any other user provided spectrum. The software also includes the complete color database of paints from NCS comprising 1950 types. This helps to evaluate how different colors modify the reflected spectra from different lamps. All spectroscopic measurements have been validated with recommendations from CIELAB and ISO from NCS database.

Clinical study on natural gingival color.

PubMed

Gómez-Polo, Cristina; Montero, Javier; Gómez-Polo, Miguel; Martín Casado, Ana María

2018-05-29

The aims of the study were: to describe the gingival color surrounding the upper incisors in three sites in the keratinized gingiva, analyzing the effect of possible factors which modulate (socio-demographic and behavioral) intersubject variability; to study whether the gingiva color is the same in all three locations and to describe intrasubject color differences in the keratinized gingiva band. Using the CIELAB color system, three reference areas (free gingival margin, keratinized gingival body, and birth or upper part of the keratinized gingiva) were studied in 259 individuals, as well as the related socio-demographic factors, oral habits and the chronic intake of medication. Shadepilot™ spectrophotometer was used. Descriptive and inferential statistical analysis was performed. There are statistically significant differences between males and females for coordinates L* and a* in the middle and free gingival margin. For the b* coordinate, there are differences between males and females in the three locations studied (p < 0.05). The minimum and maximum coordinates in which the CIELAB natural gingival space is delimited are L* minima 28.3, L* maximum 65.4, a* minimum 11.1, a* maximum 37.2, b* minimum 6.9, and b* maximum 25.2*. Age, smoking, and the chronic intake of medication had no significant effect on gum color. There are perceptible color differences within the keratinized gingiva band. These chromatic differences must be taken into account if the prosthetic characterization of gingival tissue is to be considered acceptable. There are significant differences between the color coordinates of the three sites studied in the keratinized gingiva of men and women.

Study of factors affecting the appearance of colors under microscopes

NASA Astrophysics Data System (ADS)

Zakizadeh, Roshanak; Martinez-Garcia, Juan; Raja, Kiran B.; Siakidis, Christos

2013-11-01

The variation of colors in microscopy systems can be quite critical for some users. To address this problem, a study is conducted to analyze how different factors such as size of the sample, intensity of the microscope's light source and the characteristics of the material like chroma and saturation can affect the color appearance through the eyepiece of the microscope. To study the changes in colors considering these factors, the spectral reflectance of 24 colors of GretagMacbeth Classic ColorChecker® and Mini ColorChecker® which are placed under a Nikon ECLIPSE MA200 microscope®2 using dark filed and bright field illuminations which result in different intensity levels, is measured using a spectroradiometer®3 which was placed in front of the eyepiece of the microscope. The results are compared with the original data from N. Ohta1. The evaluation is done by observing the shift in colors in the CIE 1931 Chromaticity Diagram and the CIELAB space, also by applying a wide set of color-difference formulas, namely: CIELAB, CMC, BFD, CIE94, CIEDE2000, DIN99d and DIN99b. Furthermore, to emphasize on the color regions in which the highest difference is observed, the authors have obtained the results from another microscope; Olympus SZX10®4, which in this case the measurement is done by mounting the spectroradiometer to the camera port of the microscope. The experiment leads to some interesting results, among which is the consistency in the highest difference observed considering different factors or how the change in saturation of the samples of the same hue can affect the results.

Studying mixing in Non-Newtonian blue maize flour suspensions using color analysis.

PubMed

Trujillo-de Santiago, Grissel; Rojas-de Gante, Cecilia; García-Lara, Silverio; Ballescá-Estrada, Adriana; Alvarez, Mario Moisés

2014-01-01

Non-Newtonian fluids occur in many relevant flow and mixing scenarios at the lab and industrial scale. The addition of acid or basic solutions to a non-Newtonian fluid is not an infrequent operation, particularly in Biotechnology applications where the pH of Non-Newtonian culture broths is usually regulated using this strategy. We conducted mixing experiments in agitated vessels using Non-Newtonian blue maize flour suspensions. Acid or basic pulses were injected to reveal mixing patterns and flow structures and to follow their time evolution. No foreign pH indicator was used as blue maize flours naturally contain anthocyanins that act as a native, wide spectrum, pH indicator. We describe a novel method to quantitate mixedness and mixing evolution through Dynamic Color Analysis (DCA) in this system. Color readings corresponding to different times and locations within the mixing vessel were taken with a digital camera (or a colorimeter) and translated to the CIELab scale of colors. We use distances in the Lab space, a 3D color space, between a particular mixing state and the final mixing point to characterize segregation/mixing in the system. Blue maize suspensions represent an adequate and flexible model to study mixing (and fluid mechanics in general) in Non-Newtonian suspensions using acid/base tracer injections. Simple strategies based on the evaluation of color distances in the CIELab space (or other scales such as HSB) can be adapted to characterize mixedness and mixing evolution in experiments using blue maize suspensions.

Effect of coffee and a cola-based soft drink on the color stability of bleached bovine incisors considering the time elapsed after bleaching.

PubMed

Pirolo, Rodrigo; Mondelli, Rafael Francisco Lia; Correr, Gisele Maria; Gonzaga, Carla Castiglia; Furuse, Adilson Yoshio

2014-01-01

There is no consensus about the waiting time necessary for the patient to start consuming beverages containing colorants again after bleaching. To evaluate the influence of beverages with coloring agents on bleached bovine incisors considering the time elapsed after bleaching. Sixty bovine incisors were bleached with 35% hydrogen peroxide for in-office use (Whiteness HP Max) and divided into 10 groups. The color was evaluated with a spectrophotometer (Spectro Shade MICRO) before and after bleaching, employing the CIE-Lab system. After bleaching, the teeth were exposed for 5 min to coffee or cola-based soft drink (CBSD) at different periods after bleaching: 10 min, 1 h, 24 h, 48 h, and 72 h. Color (∆E) and lightness (∆L) variations were obtained from the CIE-Lab coordinates. Data were subjected to two-way ANOVA and Tukey HSD tests (p<0.05). Significant differences were observed between groups for both the ∆L and ∆E values (p<0.001). All specimens presented a decrease in brightness (negative ∆L). The highest ∆E values were observed for teeth stained with a CBSD at 10 min and 1 h (4.12 and 4.16, respectively). Teeth pigmented with coffee presented ∆E values below 3.3 units for all evaluation times. The exposure to coffee after bleaching causes less color changes than the exposure to a CBSD regardless of the time after bleaching.

Influence of prefermentative cold maceration on the color and anthocyanic copigmentation of organic Tempranillo wines elaborated in a warm climate.

PubMed

Gordillo, Belen; López-Infante, M Isabel; Ramírez-Pérez, Pilar; González-Miret, M Lourdes; Heredia, Francisco J

2010-06-09

The stabilization of red wine color by the copigmentation phenomenon is a crucial process that does not always proceed favorably under natural conditions during the first stages of vinification. The impact of the prefermentative cold maceration technique on the phenolic composition and magnitude of the copigmentation level of organic Tempranillo wines elaborated in a warm climate have been studied as an enological alternative to the traditional maceration for obtaining highly colored wines. Tristimulus colorimetry was applied to study the color of wines during vinification, and a high-performance liquid chromatography (HPLC) procedure was used for the analysis of phenolic compounds. Spectrophotometric and colorimetric analyses were also performed to evaluate the copigmentation level of the wines. Significant chemical and color differences were found depending on the maceration technique applied. Prefermentative cold macerated wines were richer in those compounds accounting directly for the color of red wine (anthocyanins) and those involved in anthocyanin stabilization through copigmentation reactions (phenols), which was in accordance with the higher copigmentation degree and darker, more saturated and vivid bluish colors. The evaluation of the copigmentation based on colorimetric parameters in the CIELAB color space showed that prefermentative cold maceration caused greater effectiveness of copigmentation than traditional maceration since it induces more important and hence more easily perceptible color changes.

Color digital halftoning taking colorimetric color reproduction into account

NASA Astrophysics Data System (ADS)

Haneishi, Hideaki; Suzuki, Toshiaki; Shimoyama, Nobukatsu; Miyake, Yoichi

1996-01-01

Taking colorimetric color reproduction into account, the conventional error diffusion method is modified for color digital half-toning. Assuming that the input to a bilevel color printer is given in CIE-XYZ tristimulus values or CIE-LAB values instead of the more conventional RGB or YMC values, two modified versions based on vector operation in (1) the XYZ color space and (2) the LAB color space were tested. Experimental results show that the modified methods, especially the method using the LAB color space, resulted in better color reproduction performance than the conventional methods. Spatial artifacts that appear in the modified methods are presented and analyzed. It is also shown that the modified method (2) with a thresholding technique achieves a good spatial image quality.

Influence of imaging resolution on color fidelity in digital archiving.

PubMed

Zhang, Pengchang; Toque, Jay Arre; Ide-Ektessabi, Ari

2015-11-01

Color fidelity is of paramount importance in digital archiving. In this paper, the relationship between color fidelity and imaging resolution was explored by calculating the color difference of an IT8.7/2 color chart with a CIELAB color difference formula for scanning and simulation images. Microscopic spatial sampling was used in selecting the image pixels for the calculations to highlight the loss of color information. A ratio, called the relative imaging definition (RID), was defined to express the correlation between image resolution and color fidelity. The results show that in order for color differences to remain unrecognizable, the imaging resolution should be at least 10 times higher than the physical dimension of the smallest feature in the object being studied.

Reconstruction of reflectance data using an interpolation technique.

PubMed

Abed, Farhad Moghareh; Amirshahi, Seyed Hossein; Abed, Mohammad Reza Moghareh

2009-03-01

A linear interpolation method is applied for reconstruction of reflectance spectra of Munsell as well as ColorChecker SG color chips from the corresponding colorimetric values under a given set of viewing conditions. Hence, different types of lookup tables (LUTs) have been created to connect the colorimetric and spectrophotometeric data as the source and destination spaces in this approach. To optimize the algorithm, different color spaces and light sources have been used to build different types of LUTs. The effects of applied color datasets as well as employed color spaces are investigated. Results of recovery are evaluated by the mean and the maximum color difference values under other sets of standard light sources. The mean and the maximum values of root mean square (RMS) error between the reconstructed and the actual spectra are also calculated. Since the speed of reflectance reconstruction is a key point in the LUT algorithm, the processing time spent for interpolation of spectral data has also been measured for each model. Finally, the performance of the suggested interpolation technique is compared with that of the common principal component analysis method. According to the results, using the CIEXYZ tristimulus values as a source space shows priority over the CIELAB color space. Besides, the colorimetric position of a desired sample is a key point that indicates the success of the approach. In fact, because of the nature of the interpolation technique, the colorimetric position of the desired samples should be located inside the color gamut of available samples in the dataset. The resultant spectra that have been reconstructed by this technique show considerable improvement in terms of RMS error between the actual and the reconstructed reflectance spectra as well as CIELAB color differences under the other light source in comparison with those obtained from the standard PCA technique.

Optical spectral imaging of degeneration of articular cartilage

NASA Astrophysics Data System (ADS)

Kinnunen, Jussi; Jurvelin, Jukka S.; Mäkitalo, Jaana; Hauta-Kasari, Markku; Vahimaa, Pasi; Saarakkala, Simo

2010-07-01

Osteoarthritis (OA) is a common musculoskeletal disorder often diagnosed during arthroscopy. In OA, visual color changes of the articular cartilage surface are typically observed. We demonstrate in vitro the potential of visible light spectral imaging (420 to 720 nm) to quantificate these color changes. Intact bovine articular cartilage samples (n=26) are degraded both enzymatically using the collagenase and mechanically using the emery paper (P60 grit, 269 μm particle size). Spectral images are analyzed by using standard CIELAB color coordinates and the principal component analysis (PCA). After collagenase digestion, changes in the CIELAB coordinates and projection of the spectra to PCA eigenvector are statistically significant (p<0.05). After mechanical degradation, the grinding tracks could not be visualized in the RGB presentation, i.e., in the visual appearance of the sample to the naked eye under the D65 illumination. However, after projecting to the chosen eigenvector, the grinding tracks are revealed. The tracks are also seen by using only one wavelength, i.e., 469 nm, however, the contrast in the projection image is 1.6 to 2.5 times higher. Our results support the idea that the spectral imaging can be used for evaluation of the integrity of the cartilage surface.

Color standardization in whole slide imaging using a color calibration slide

PubMed Central

Bautista, Pinky A.; Hashimoto, Noriaki; Yagi, Yukako

2014-01-01

Background: Color consistency in histology images is still an issue in digital pathology. Different imaging systems reproduced the colors of a histological slide differently. Materials and Methods: Color correction was implemented using the color information of the nine color patches of a color calibration slide. The inherent spectral colors of these patches along with their scanned colors were used to derive a color correction matrix whose coefficients were used to convert the pixels’ colors to their target colors. Results: There was a significant reduction in the CIELAB color difference, between images of the same H & E histological slide produced by two different whole slide scanners by 3.42 units, P < 0.001 at 95% confidence level. Conclusion: Color variations in histological images brought about by whole slide scanning can be effectively normalized with the use of the color calibration slide. PMID:24672739

Studying Mixing in Non-Newtonian Blue Maize Flour Suspensions Using Color Analysis

PubMed Central

Trujillo-de Santiago, Grissel; Rojas-de Gante, Cecilia; García-Lara, Silverio; Ballescá-Estrada, Adriana; Alvarez, Mario Moisés

2014-01-01

Background Non-Newtonian fluids occur in many relevant flow and mixing scenarios at the lab and industrial scale. The addition of acid or basic solutions to a non-Newtonian fluid is not an infrequent operation, particularly in Biotechnology applications where the pH of Non-Newtonian culture broths is usually regulated using this strategy. Methodology and Findings We conducted mixing experiments in agitated vessels using Non-Newtonian blue maize flour suspensions. Acid or basic pulses were injected to reveal mixing patterns and flow structures and to follow their time evolution. No foreign pH indicator was used as blue maize flours naturally contain anthocyanins that act as a native, wide spectrum, pH indicator. We describe a novel method to quantitate mixedness and mixing evolution through Dynamic Color Analysis (DCA) in this system. Color readings corresponding to different times and locations within the mixing vessel were taken with a digital camera (or a colorimeter) and translated to the CIELab scale of colors. We use distances in the Lab space, a 3D color space, between a particular mixing state and the final mixing point to characterize segregation/mixing in the system. Conclusion and Relevance Blue maize suspensions represent an adequate and flexible model to study mixing (and fluid mechanics in general) in Non-Newtonian suspensions using acid/base tracer injections. Simple strategies based on the evaluation of color distances in the CIELab space (or other scales such as HSB) can be adapted to characterize mixedness and mixing evolution in experiments using blue maize suspensions. PMID:25401332

Effect of coffe and a cola-based soft drink on the color stability of bleached bovine incisors considering the time elapsed after bleaching

PubMed Central

PIROLO, Rodrigo; MONDELLI, Rafael Francisco Lia; CORRER, Gisele Maria; GONZAGA, Carla Castiglia; FURUSE, Adilson Yoshio

2014-01-01

There is no consensus about the waiting time necessary for the patient to start consuming beverages containing colorants again after bleaching. Objective: To evaluate the influence of beverages with coloring agents on bleached bovine incisors considering the time elapsed after bleaching. Materials and methods: Sixty bovine incisors were bleached with 35% hydrogen peroxide for in-office use (Whiteness HP Max) and divided into 10 groups. The color was evaluated with a spectrophotometer (Spectro Shade MICRO) before and after bleaching, employing the CIE-Lab system. After bleaching, the teeth were exposed for 5 min to coffee or cola-based soft drink (CBSD) at different periods after bleaching: 10 min, 1 h, 24 h, 48 h, and 72 h. Color (∆E) and lightness (∆L) variations were obtained from the CIE-Lab coordinates. Data were subjected to two-way ANOVA and Tukey HSD tests (p<0.05). Results: Significant differences were observed between groups for both the ∆L and ∆E values (p<0.001). All specimens presented a decrease in brightness (negative ∆L). The highest ∆E values were observed for teeth stained with a CBSD at 10 min and 1 h (4.12 and 4.16, respectively). Teeth pigmented with coffee presented ∆E values below 3.3 units for all evaluation times. Conclusion: The exposure to coffee after bleaching causes less color changes than the exposure to a CBSD regardless of the time after bleaching. PMID:25075672

Long-term memory color investigation: culture effect and experimental setting factors.

PubMed

Zhu, Yuteng; Luo, Ming Ronnier; Fischer, Sebastian; Bodrogi, Peter; Khanh, Tran Quoc

2017-10-01

Memory colors generated continuous interest in the color community. Previous studies focused on reflecting color chips and color samples in real scenes or on monitors. The cognitive effect of culture was rarely considered. In this paper, we performed a comprehensive investigation of the long-term memory colors of 26 familiar objects using the asymmetric color matching method among Chinese and German observers on a display. Three experiments were conducted to evaluate the variations introduced by culture, context-based gray image, and initial matching color. Memory colors of important objects were collected and representative memory colors were quantified in terms of CIELAB L * , a * , and b * values. The intra- and inter-observer variations were analyzed by mean-color-difference-from-mean values and chromatic ellipses. The effects of different cultural groups and experimental settings were also shown.

A subjective evaluation of high-chroma color with wide color-gamut display

NASA Astrophysics Data System (ADS)

Kishimoto, Junko; Yamaguchi, Masahiro; Ohyama, Nagaaki

2009-01-01

Displays tends to expand its color gamut, such as multi-primary color display, Adobe RGB and so on. Therefore displays got possible to display high chroma colors. However sometimes, we feel unnatural some for the image which only expanded chroma. Appropriate gamut mapping method to expand color gamut is not proposed very much. We are attempting preferred expanded color reproduction on wide color gamut display utilizing high chroma colors effectively. As a first step, we have conducted an experiment to investigate the psychological effect of color schemes including highly saturated colors. We used the six-primary-color projector that we have developed for the presentation of test colors. The six-primary-color projector's gamut volume in CIELAB space is about 1.8 times larger than the normal RGB projector. We conducted a subjective evaluation experiment using the SD (Semantic Differential) technique to find the quantitative psychological effect of high chroma colors.

On Adapting the Tensor Voting Framework to Robust Color Image Denoising

NASA Astrophysics Data System (ADS)

Moreno, Rodrigo; Garcia, Miguel Angel; Puig, Domenec; Julià, Carme

This paper presents an adaptation of the tensor voting framework for color image denoising, while preserving edges. Tensors are used in order to encode the CIELAB color channels, the uniformity and the edginess of image pixels. A specific voting process is proposed in order to propagate color from a pixel to its neighbors by considering the distance between pixels, the perceptual color difference (by using an optimized version of CIEDE2000), a uniformity measurement and the likelihood of the pixels being impulse noise. The original colors are corrected with those encoded by the tensors obtained after the voting process. Peak to noise ratios and visual inspection show that the proposed methodology has a better performance than state-of-the-art techniques.

Predicting transmittance spectra of electrophotographic color prints

NASA Astrophysics Data System (ADS)

Mourad, Safer; Emmel, Patrick; Hersch, Roger D.

2000-12-01

For dry toner electrophotographic color printers, we present a numerical simulation model describing the color printer responses based on a physical characterization of the different electrophotographic process steps. The proposed model introduces a Cross Transfer Efficiency designed to predict the color transmittance spectra of multi-color prints by taking into account the transfer influence of each deposited color toner layer upon the other layers. The simulation model leads to a better understanding of the factors that have an impact on printing quality. In order to avoid the additional optical non-linearities produced by light reflection on paper, we have limited the present investigation to transparency prints. The proposed model succeeded to predict the transmittance spectra of printed wedges combining two color toner layers with a mean deviation less than CIE-LAB (Delta) E equals 2.5.

Optical tests for using smartphones inside medical devices

NASA Astrophysics Data System (ADS)

Bernat, Amir S.; Acobas, Jennifer K.; Phang, Ye Shang; Hassan, David; Bolton, Frank J.; Levitz, David

2018-02-01

Smartphones are currently used in many medical applications and are more frequently being integrated into medical imaging devices. The regulatory requirements in existence today however, particularly the standardization of smartphone imaging through validation and verification testing, only partially cover imaging characteristics with a smartphone. Specifically, it has been shown that smartphone camera specifications are of sufficient quality for medical imaging, and there are devices which comply with the FDA's regulatory requirements for a medical device such as a device's field of view, direction of viewing and optical resolution and optical distortion. However, these regulatory requirements do not call specifically for color testing. Images of the same object using automatic settings or different light sources can show different color composition. Experimental results showing such differences are presented. Under some circumstances, such differences in color composition could potentially lead to incorrect diagnoses. It is therefore critical to control the smartphone camera and illumination parameters properly. This paper examines different smartphone camera settings that affect image quality and color composition. To test and select the correct settings, a test methodology is proposed. It aims at evaluating and testing image color correctness and white balance settings for mobile phones and LED light sources. Emphasis is placed on color consistency and deviation from gray values, specifically by evaluating the ΔC values based on the CIEL*a*b* color space. Results show that such standardization minimizes differences in color composition and thus could reduce the risk of a wrong diagnosis.

Fuzzy Logic-Based Filter for Removing Additive and Impulsive Noise from Color Images

NASA Astrophysics Data System (ADS)

Zhu, Yuhong; Li, Hongyang; Jiang, Huageng

2017-12-01

This paper presents an efficient filter method based on fuzzy logics for adaptively removing additive and impulsive noise from color images. The proposed filter comprises two parts including noise detection and noise removal filtering. In the detection part, the fuzzy peer group concept is applied to determine what type of noise is added to each pixel of the corrupted image. In the filter part, the impulse noise is deducted by the vector median filter in the CIELAB color space and an optimal fuzzy filter is introduced to reduce the Gaussian noise, while they can work together to remove the mixed Gaussian-impulse noise from color images. Experimental results on several color images proves the efficacy of the proposed fuzzy filter.

Methods for computing color anaglyphs

NASA Astrophysics Data System (ADS)

McAllister, David F.; Zhou, Ya; Sullivan, Sophia

2010-02-01

A new computation technique is presented for calculating pixel colors in anaglyph images. The method depends upon knowing the RGB spectral distributions of the display device and the transmission functions of the filters in the viewing glasses. It requires the solution of a nonlinear least-squares program for each pixel in a stereo pair and is based on minimizing color distances in the CIEL*a*b* uniform color space. The method is compared with several techniques for computing anaglyphs including approximation in CIE space using the Euclidean and Uniform metrics, the Photoshop method and its variants, and a method proposed by Peter Wimmer. We also discuss the methods of desaturation and gamma correction for reducing retinal rivalry.

Relevant optical properties for direct restorative materials.

PubMed

Pecho, Oscar E; Ghinea, Razvan; do Amaral, Erika A Navarro; Cardona, Juan C; Della Bona, Alvaro; Pérez, María M

2016-05-01

To evaluate relevant optical properties of esthetic direct restorative materials focusing on whitened and translucent shades. Enamel (E), body (B), dentin (D), translucent (T) and whitened (Wh) shades for E (WhE) and B (WhB) from a restorative system (Filtek Supreme XTE, 3M ESPE) were evaluated. Samples (1 mm thick) were prepared. Spectral reflectance (R%) and color coordinates (L*, a*, b*, C* and h°) were measured against black and white backgrounds, using a spectroradiometer, in a viewing booth, with CIE D65 illuminant and d/0° geometry. Scattering (S) and absorption (K) coefficients and transmittance (T%) were calculated using Kubelka-Munk's equations. Translucency (TP) and opalescence (OP) parameters and whiteness index (W*) were obtained from differences of CIELAB color coordinates. R%, S, K and T% curves from all shades were compared using VAF (Variance Accounting For) coefficient with Cauchy-Schwarz inequality. Color coordinates and optical parameters were statistically analyzed using one-way ANOVA, Tukey's test with Bonferroni correction (α=0.0007). Spectral behavior of R% and S were different for T shades. In addition, T shades showed the lowest R%, S and K values, as well as the highest T%, TP an OP values. In most cases, WhB shades showed different color and optical properties (including TP and W*) than their corresponding B shades. WhE shades showed similar mean W* values and higher mean T% and TP values than E shades. When using whitened or translucent composites, the final color is influenced not only by the intraoral background but also by the color and optical properties of multilayers used in the esthetic restoration. Copyright © 2016 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

The effect of various disinfectants on dental shade guides.

PubMed

Huang, Peterson Y; Masri, Radi; Romberg, Elaine; Driscoll, Carl F

2014-09-01

Dental shade guides are used to evaluate tooth color before prosthodontic procedures and are subjected to disinfection after use. The effect of disinfection on shade guides has not been thoroughly investigated. The purpose of this study was to evaluate the effect of disinfectants on the color of shade tabs. Changes in the color (ΔE) of VITA Classical Shade Guide tabs were measured with a VITA Easyshade spectrophotometer in the CIELAB system and calculated after being subjected to Cavicide, Asepticare TB, Sporicidin, and distilled water (control) over a simulated period of 2 years. Statistical analysis was accomplished by a 2-way analysis of variance followed by the Tukey honestly significant difference (HSD) test (α=.05). A significant difference was noted in the degree of shade tab color change, depending on the type of disinfectant used (F=153.2, P<.001). No significant difference was noted in the amount of shade tab color change that occurred after disinfection among the different shade tabs used (F=0.611, P=.865), nor was a significant interaction noted between the type of disinfectant and the different shade tabs used (F=0.7, P=.919). Asepticare TB showed the least significant amount of change (ΔE=0.401), and Sporicidin (ΔE=0.889) and the control (ΔE=0.969) showed significantly more color change than Asepticare TB but less than Cavicide (ΔE=1.198). The average total CIELAB color difference for 50% human perceptibility is approximately 1 unit (under standardized laboratory conditions). In the oral cavity, however, an average change of 3.7 ΔE units could still allow teeth to be perceived as having the same color. Therefore, although the results are statistically significant, they may not be clinically important. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Tentative characterization of precursor compounds and co-factors of pigment formation in production of 'wu mi' from Vaccinium bracteatum Thunb. Leaves.

PubMed

Fan, Mingcong; Fan, Yihui; Huang, Weiping; Wang, Li; Li, Yan; Qian, Haifeng; Zhang, Hui; Qi, Xiguang

2018-10-01

Vaccinium bracteatum leaves (VBTL) are traditionally used in China to dye rice grains, which assume a deep blue color, named 'Wu mi'. Information on the mechanism of pigment formation is limited. In this study, CIELAB color space parameters were used to represent the color of 'Wu mi'. Precursor compounds of pigments formed during the dyeing process were identified by UPLC Q-TOF MS analysis. The changes in co-factors for pigment formation in VBTL were measured at different growth stages. The L ∗ and b ∗ values of dyed rice increased as the leaves aged, whereas a ∗ values showed irregular changes. Six compounds were tentatively identified as pigment precursors by UPLC Q-TOF MS analysis. The pH and β-glucosidase activity at different growth stages of VBTL were indicated to be crucial co-factors for pigment formation. A tentative hypothesis is presented that iridoid glycosides are hydrolyzed by acids and β-glucosidases to form a dialdehyde structure that binds covalently with amino residues of lysine side chains in rice protein molecules. Copyright © 2018 Elsevier Ltd. All rights reserved.

Development of an adaptive bilateral filter for evaluating color image difference

NASA Astrophysics Data System (ADS)

Wang, Zhaohui; Hardeberg, Jon Yngve

2012-04-01

Spatial filtering, which aims to mimic the contrast sensitivity function (CSF) of the human visual system (HVS), has previously been combined with color difference formulae for measuring color image reproduction errors. These spatial filters attenuate imperceptible information in images, unfortunately including high frequency edges, which are believed to be crucial in the process of scene analysis by the HVS. The adaptive bilateral filter represents a novel approach, which avoids the undesirable loss of edge information introduced by CSF-based filtering. The bilateral filter employs two Gaussian smoothing filters in different domains, i.e., spatial domain and intensity domain. We propose a method to decide the parameters, which are designed to be adaptive to the corresponding viewing conditions, and the quantity and homogeneity of information contained in an image. Experiments and discussions are given to support the proposal. A series of perceptual experiments were conducted to evaluate the performance of our approach. The experimental sample images were reproduced with variations in six image attributes: lightness, chroma, hue, compression, noise, and sharpness/blurriness. The Pearson's correlation values between the model-predicted image difference and the observed difference were employed to evaluate the performance, and compare it with that of spatial CIELAB and image appearance model.

Effects of high pressure application (400 and 900 MPa) and refrigerated storage time on the oxidative stability of sliced skin vacuum packed dry-cured ham.

PubMed

Clariana, Maria; Guerrero, Luis; Sárraga, Carmen; Garcia-Regueiro, José A

2012-02-01

The effect of high pressure processing at 400 MPa and 900 MPa on the oxidative stability of sliced and vacuum packaged commercial dry-cured ham was determined by analyzing the antioxidant enzyme activities, TBARS levels (thiobarbituric acid reactive substances), vitamin E content and physicochemical characteristics during refrigerated storage for 50 days in different light conditions. In dry-cured ham pressurized at 400 MPa color changes and sensory analyses were also assessed. The high pressure process at 900 MPa produced a decrease in superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) activities and increased vitamin E content. In contrast, pressurization at 400 MPa, increased SOD activity, and showed no effect on vitamin E content and GSHPx activity. In general the physicochemical parameters determined (fat, moisture and collagen) were unaffected by pressurization. Treatment at 400 MPa increased the instrumental color measurement of lightness (L* values, CIELAB). This level of pressure also modified the hardness, chewiness, saltiness and color intensity. These changes of the sensory attributes in dry-cured ham were significant, but small. Copyright © 2011 Elsevier Ltd. All rights reserved.

Color stability of shade guides after autoclave sterilization.

PubMed

Schmeling, Max; Sartori, Neimar; Monteiro, Sylvio; Baratieri, Luiz

2014-01-01

This study evaluated the influence of 120 autoclave sterilization cycles on the color stability of two commercial shade guides (Vita Classical and Vita System 3D-Master). The specimens were evaluated by spectrophotometer before and after the sterilization cycles. The color was described using the three-dimensional CIELab system. The statistical analysis was performed in three chromaticity coordinates, before and after sterilization cycles, using the paired samples t test. All specimens became darker after autoclave sterilization cycles. However, specimens of Vita Classical became redder, while those of the Vita System 3D-Master became more yellow. Repeated cycles of autoclave sterilization caused statistically significant changes in the color coordinates of the two shade guides. However, these differences are considered clinically acceptable.

Matching the optical properties of direct esthetic dental restorative materials to those of human enamel and dentin

NASA Astrophysics Data System (ADS)

Ragain, James Carlton, Jr.

One of the goals of the restorative dentist is to restore the appearance of the natural dentition. Clinical matching of teeth and restorative materials are seldom accurate and shade selection techniques are subjective. The first specific aim of this research was to characterize the optical absorption and scattering that occurs within enamel, dentin, and composite resin and compomer restorative materials and to relate those phenomena to translucency and color. The second aim was to evaluate small color differences among composite restorative materials which would be detectable by humans. The last aim was to lay the foundation for developing an improved model of specifying layers of dental restorative materials in order to match the translucency and color to those of human enamel. The Kubelka-Munk theory was validated for enamel, dentin, and the restorative materials. These tissues and materials were then characterized in terms of their color parameters. Tooth cores were also characterized in terms of color space parameters. Human subjects were evaluated for their abilities to discriminate small color differences in the dental composite resin materials. The following conclusions were derived from this study: (1) Kubelka-Munk theory accurately predicts the diffuse reflectance spectra of enamel, dentin, and the direct esthetic dental restorative materials studied. (2) Scattering and absorption coefficients of the dental tissues and esthetic restorative materials can be directly calculated from diffuse reflectance measurements of a uniformly thick slab of tissue/material using black and white backings and the appropriate refractive index. (3) For tooth cores, there is a positive correlation between L* and b* and a negative correlation between L* and a*. (4) The range of translucency parameters for the restorative materials studied does not match those of enamel and dentin. (5) None of the shades of the dental composite resin restorative materials studied fit into the dentin color space. (6) For the materials studied, the CMC (1:1) color difference formula gives a better receiver operating characteristic than the CIELAB or CMC (2:1) formulas for acceptance.

Quantitative assessment of skin, hair, and iris variation in a diverse sample of individuals and associated genetic variation.

PubMed

Norton, Heather L; Edwards, Melissa; Krithika, S; Johnson, Monique; Werren, Elizabeth A; Parra, Esteban J

2016-08-01

The main goals of this study are to 1) quantitatively measure skin, hair, and iris pigmentation in a diverse sample of individuals, 2) describe variation within and between these samples, and 3) demonstrate how quantitative measures can facilitate genotype-phenotype association tests. We quantitatively characterize skin, hair, and iris pigmentation using the Melanin (M) Index (skin) and CIELab values (hair) in 1,450 individuals who self-identify as African American, East Asian, European, Hispanic, or South Asian. We also quantify iris pigmentation in a subset of these individuals using CIELab values from high-resolution iris photographs. We compare mean skin M index and hair and iris CIELab values among populations using ANOVA and MANOVA respectively and test for genotype-phenotype associations in the European sample. All five populations are significantly different for skin (P <2 × 10(-16) ) and hair color (P <2 × 10(-16) ). Our quantitative analysis of iris and hair pigmentation reinforces the continuous, rather than discrete, nature of these traits. We confirm the association of three loci (rs16891982, rs12203592, and rs12913832) with skin pigmentation and four loci (rs12913832, rs12203592, rs12896399, and rs16891982) with hair pigmentation. Interestingly, the derived rs12203592 T allele located within the IRF4 gene is associated with lighter skin but darker hair color. The quantitative methods used here provide a fine-scale assessment of pigmentation phenotype and facilitate genotype-phenotype associations, even with relatively small sample sizes. This represents an important expansion of current investigations into pigmentation phenotype and associated genetic variation by including non-European and admixed populations. Am J Phys Anthropol 160:570-581, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Effect of coping thickness and background type on the masking ability of a zirconia ceramic.

PubMed

Tabatabaian, Farhad; Taghizade, Fateme; Namdari, Mahshid

2018-01-01

The masking ability of zirconia ceramics as copings is unclear. The purpose of this in vitro study was to evaluate the effect of coping thickness and background type on the masking ability of a zirconia ceramic and to determine zirconia coping thickness cut offs for masking the backgrounds investigated. Thirty zirconia disks in 3 thickness groups of 0.4, 0.6, and 0.8 mm were placed on 9 backgrounds to measure CIELab color attributes using a spectrophotometer. The backgrounds included A1, A2, and A3.5 shade composite resin, A3 shade zirconia, nickel-chromium alloy, nonprecious gold-colored alloy, amalgam, black, and white. ΔE values were measured to determine color differences between the specimens on the A2 shade composite resin background and the same specimens on the other backgrounds. The color change (ΔE) values were compared with threshold values for acceptability (ΔE=5.5) and perceptibility (ΔE=2.6). Repeated measures ANOVA, the Bonferroni test, and 1-sample t tests were used to analyze data (α=.05). Mean ΔE values ranged between 1.44 and 7.88. The zirconia coping thickness, the background type, and their interaction affected the CIELab and ΔE values (P<.001). To achieve ideal masking, the minimum thickness of a zirconia coping should be 0.4 mm for A1 and A3.5 shade composite resin, A3 shade zirconia, and nonprecious gold-colored alloy, 0.6 mm for amalgam, and 0.8 mm for nickel-chromium alloy. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Efficacy of hydrogen-peroxide-based mouthwash in altering enamel color.

PubMed

Jaime, Ivone Maria de Lima; França, Fabiana Mantovani Gomes; Basting, Roberta Tarkany; Turssi, Cecilia Pedroso; Amaral, Flávia Lucisano Botelho

2014-02-01

To analyze the efficacy of Colgate Plax Whitening mouthwash containing 1.5% hydrogen peroxide. 30 enamel fragments, obtained from the proximal surfaces of human third molars were darkened with Orange II methyl orange. The fragments were divided into three groups according to the type of bleaching agent applied (n = 10): (1) 10% carbamide peroxide gel (positive control, PC) was applied for 2 hours/day for 28 days; (2) a solution containing 1.5% hydrogen peroxide (Plax) was applied for 4 minutes once a day for 28 days, and (3) no bleaching agent, kept in artificial saliva (negative control, AS). The specimens were kept in artificial saliva between treatment intervals. The specimens were photographed before darkening (baseline), after darkening and before lightening and on the 28th day of whitening. Afterwards, they were analyzed with color measurement software using the CIELab system. The data for the L*, a* and b* parameters were submitted to two-way ANOVA with repeated measures. The values of deltaL *, deltaa *, deltab * and deltaE* were calculated using two procedures: (1) darkened versus original, and (2) bleached versus darkened. This data was submitted to the one-way ANOVA test. Multiple comparisons were conducted using the Tukey test (alpha = 0.05). When the specimens were subjected to bleaching agents, there was a significant increase in the brightness (L* parameter) of the enamel exposed to the gel and also to the bleaching solution. However, higher brightness was observed for the PC (gel) group. As for the axis a* parameters, there were no significant differences between the bleaching products. Regarding the axis b* parameters, the PC group underwent major changes (indicating a color change toward blue chroma), statistically greater than those of the Plax group. After bleaching, there was a significantly greater color change (deltaE*) in the PC group. Although the Plax solution caused a color change, it was less than that produced by the gel. The slightest color change was observed in the control group, in which no bleach was used. The mouthwash containing hydrogen peroxide was able to lighten the darkened human enamel, but to a lesser degree than the lightening produced by 10% carbamide peroxide.

Development of a novel colorimetric sensor based on alginate beads for monitoring rainbow trout spoilage.

PubMed

Majdinasab, Marjan; Hosseini, Seyed Mohammad Hashem; Sepidname, Marziyeh; Negahdarifar, Manizheh; Li, Peiwu

2018-05-01

Alginate is a non-toxic, renewable, and linear copolymer obtained from the brown algae Laminaria digitata that can be easily shaped into beads. Its good gel forming properties have made it useful for entrapping food and pharmaceutical ingredients. In this study, alginate beads were used in a novel application as a colorimetric sensor in food intelligent packaging. Colorimetric sensor was developed through entrapping red cabbage extract as a pH indicator in alginate beads. The pH indicator beads were used in rainbow trout packaging for monitoring fillets spoilage. Color change of beads during fish storage was measured using the CIELab method. The alginate bead colorimetric sensor is validated by measuring total volatile basic nitrogen (TVB-N) levels and microbial populations in fish samples. Moreover, peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) were evaluated during storage. Results indicated that increasing the bacterial population during storage and production of proteolytic enzymes resulted in protein degradation, accumulation of volatile amine compounds, increase in the pH and finally color change of alginate beads. The values of TVB-N, pH, PV and TBARS increased with time of storage. The results of TVB-N and microbial growth were in accordance with color change of beads and CIELab data. Therefore, the proposed system enjoys a high sensitivity to pH variations and is capable of monitoring the spoilage of fish or other protein-rich products through its wide range of color changes. The alginate beads containing the red cabbage extract can, thus, be used as a low-cost colorimetric sensor for intelligent packaging applications.

Number of discernible colors for color-deficient observers estimated from the MacAdam limits.

PubMed

Perales, Esther; Martínez-Verdú, Francisco Miguel; Linhares, João Manuel Maciel; Nascimento, Sérgio Miguel Cardoso

2010-10-01

We estimated the number of colors perceived by color normal and color-deficient observers when looking at the theoretic limits of object-color stimuli. These limits, the optimal color stimuli, were computed for a color normal observer and CIE standard illuminant D65, and the resultant colors were expressed in the CIELAB and DIN99d color spaces. The corresponding color volumes for abnormal color vision were computed using models simulating for normal trichromatic observers the appearance for dichromats and anomalous trichomats. The number of colors perceived in each case was then computed from the color volumes enclosed by the optimal colors also known as MacAdam limits. It was estimated that dichromats perceive less than 1% of the colors perceived by normal trichromats and that anomalous trichromats perceive 50%-60% for anomalies in the medium-wavelength-sensitive and 60%-70% for anomalies in the long-wavelength-sensitive cones. Complementary estimates obtained similarly for the spectral locus of monochromatic stimuli suggest less impairment for color-deficient observers, a fact that is explained by the two-dimensional nature of the locus.

Light backscatter fiber optic sensor: a new tool for predicting the stability of pork emulsions containing antioxidative potato protein hydrolysate.

PubMed

Nieto, Gema; Xiong, Youling L; Payne, Fred; Castillo, Manuel

2015-02-01

The objective of this study was to determine whether light backscatter response from fresh pork meat emulsions is correlated to final product stability indices. A specially designed fiber optic measurement system was used in combination with a miniature fiber optic spectrometer to determine the intensity of light backscatter within the wavelength range 300-1100 nm (UV/VIS/NIR) at different radial distances (2, 2.5 and 3mm) with respect to the light source in pork meat emulsions with two fat levels (15%, 30%) and two levels (0, 2.5%) of the natural antioxidant hydrolyzed potato protein (HPP). Textural parameters (hardness, deformability, cohesiveness and breaking force), cooking loss, TBARS (1, 2, 3, and 7 days of storage at 4 °C) and CIELAB color coordinates of cooked emulsions were measured. The light backscatter was directly correlated with cooking losses, color, breaking force and TBARS. The optical configuration proposed would compensate for the emulsion heterogeneity, maximizing the existing correlation between the optical signal and the emulsion quality metrics.

Optical properties of pre-colored dental monolithic zirconia ceramics.

PubMed

Kim, Hee-Kyung; Kim, Sung-Hun

2016-12-01

The purposes of this study were to evaluate the optical properties of recently marketed pre-colored monolithic zirconia ceramics and to compare with those of veneered zirconia and lithium disilicate glass ceramics. Various shades of pre-colored monolithic zirconia, veneered zirconia, and lithium disilicate glass ceramic specimens were tested (17.0×17.0×1.5mm, n=5). CIELab color coordinates were obtained against white, black, and grey backgrounds with a spectrophotometer. Color differences of the specimen pairs were calculated by using the CIEDE2000 (ΔE 00 ) formula. The translucency parameter (TP) was derived from ΔE 00 of the specimen against a white and a black background. X-ray diffraction was used to determine the crystalline phases of monolithic zirconia specimens. Data were analyzed with 1-way ANOVA, Scheffé post hoc, and Pearson correlation testing (α=0.05). For different shades of the same ceramic brand, there were significant differences in L * , a * , b * , and TP values in most ceramic brands. With the same nominal shade (A2), statistically significant differences were observed in L * , a * , b * , and TP values among different ceramic brands and systems (P<0.001). The color differences between pre-colored monolithic zirconia and veneered zirconia or lithium disilicate glass ceramics of the corresponding nominal shades ranged beyond the acceptability threshold. Due to the high L * values and low a * and b * values, pre-colored monolithic zirconia ceramics can be used with additional staining to match neighboring restorations or natural teeth. Due to their high value and low chroma, unacceptable color mismatch with adjacent ceramic restorations might be expected. Copyright © 2016 Elsevier Ltd. All rights reserved.

Distinction of Green Sweet Peppers by Using Various Color Space Models and Computation of 3 Dimensional Location Coordinates of Recognized Green Sweet Peppers Based on Parallel Stereovision System

NASA Astrophysics Data System (ADS)

Bachche, Shivaji; Oka, Koichi

2013-06-01

This paper presents the comparative study of various color space models to determine the suitable color space model for detection of green sweet peppers. The images were captured by using CCD cameras and infrared cameras and processed by using Halcon image processing software. The LED ring around the camera neck was used as an artificial lighting to enhance the feature parameters. For color images, CieLab, YIQ, YUV, HSI and HSV whereas for infrared images, grayscale color space models were selected for image processing. In case of color images, HSV color space model was found more significant with high percentage of green sweet pepper detection followed by HSI color space model as both provides information in terms of hue/lightness/chroma or hue/lightness/saturation which are often more relevant to discriminate the fruit from image at specific threshold value. The overlapped fruits or fruits covered by leaves can be detected in better way by using HSV color space model as the reflection feature from fruits had higher histogram than reflection feature from leaves. The IR 80 optical filter failed to distinguish fruits from images as filter blocks useful information on features. Computation of 3D coordinates of recognized green sweet peppers was also conducted in which Halcon image processing software provides location and orientation of the fruits accurately. The depth accuracy of Z axis was examined in which 500 to 600 mm distance between cameras and fruits was found significant to compute the depth distance precisely when distance between two cameras maintained to 100 mm.

Association between modification of phenolic profiling and development of wine color during alcohol fermentation.

PubMed

Li, Si-Yu; Liu, Pei-Tong; Pan, Qiu-Hong; Shi, Ying; Duan, Chang-Qing

2015-04-01

To solve the problem of wine color instability in western China, different additives (the maceration enzymes Vinozym G and Ex-color, yeasts VR5 and Red Star, and commercial tannins) were added during alcoholic fermentation of Syrah (Vitis vinifera L.). The phenolic profile and color characteristics of wine were examined using high performance liquid chromatography mass spectrometry and CIELAB, respectively. The results showed that the combination of the enzyme Ex-color with the Red Star yeast eased the release of non-anthocyanins from grape berries into wine, whereas the use of enzyme Vinozym G and VR5 yeast enhanced the concentration of anthocyanins and achieved a higher red hue (a* value) and a lower yellow hue (b* value) in the wine. The addition of commercial tannins greatly promoted the level of gallic acid in the wine and led to a relatively higher concentration of anthocyanins. Partial least-squares regression analysis was used to find out the major phenolics, which were in close relation with color parameters; principal component analysis was used to evaluate the contribution of different winemaking techniques to wine color. The combination of these 2 analytic methods indicated that Vinozym G and VR5 yeast together with commercial tannins should be an appropriate combination to enhance the stability of wine color during alcohol fermentation, which was related to a significant increase in cyanidin-3-O-(6-O-acetyl)-glucoside, cyanidin-3-O-(6-O-coumaryl)-glucoside, trans-peonidin-3-O-(6-O-coumaryl)-glucoside, trans-malvidin-3-O-(6-O-coumaryl)-glucoside, and malvidin-3-O-(6-O-acetyl)-glucoside-pyruvic acid, all of which played an important role in stabilizing wine color. © 2015 Institute of Food Technologists®

Color Compatibility of Gingival Shade Guides and Gingiva-Colored Dental Materials with Healthy Human Gingiva.

PubMed

Sarmast, Nima D; Angelov, Nikola; Ghinea, Razvan; Powers, John M; Paravina, Rade D

The CIELab and CIEDE2000 coverage error (ΔE* COV and ΔE' COV , respectively) of basic shades of different gingival shade guides and gingiva-colored restorative dental materials (n = 5) was calculated as compared to a previously compiled database on healthy human gingiva. Data were analyzed using analysis of variance with Tukey-Kramer multiple-comparison test (P < .05). A 50:50% acceptability threshold of 4.6 for ΔE* and 4.1 for ΔE' was used to interpret the results. ΔE* COV / ΔE' COV ranged from 4.4/3.5 to 8.6/6.9. The majority of gingival shade guides and gingiva-colored restorative materials exhibited statistically significant coverage errors above the 50:50% acceptability threshold and uneven shade distribution.

Comparison of Standard Link Color Visibility Between Young Adults and Elderly Adults

NASA Astrophysics Data System (ADS)

Saito, Daisuke; Saito, Keiichi; Notomi, Kazuhiro; Saito, Masao

The rapid dissemination of the World Wide Web raises the issue of the Web accessibility, and one of the important things is the combination of a foreground color and a background color. In our previous study, the visibility of web-safe colors on the white background was examined, and the blue used for unvisited standard link color was found high visibility in wide range of ages. Since the usage of the blue and an underline are recommended as a link, in this study, we examined high-visibility background colors to the unvisited standard link color, i.e. blue. One hundred and twenty three background colors to the blue were examined using pair comparison method, and the relationship between the visibility and the color difference was discussed on the uniform color space, CIELAB (L*a*b* color space). As the result, effective background colors to the standard link color were determined on the CIE LAB, that is, L* larger than 68, a* smaller than 50, and b* larger than -50 provided high visibility in wide range of ages.

Influence of Photoinitiator on Accelerated Artificial Aging and Bond Strength of Experimental Resin Cements.

PubMed

Righi, Helouise; Costa, Ana Rosa; Oliveira, Dayane Carvalho Ramos Salles de; Abuna, Gabriel Flores; Sinhoreti, Mario Alexandre Coelho; Naufel, Fabiana Scarparo

2018-01-01

The goal of this study was to evaluate in vitro the effect of the photoinitiator phenylpropanedione (PPD), alone or combined with camphorquinone (CQ), on color stability of photoactivated resin cements and their bond strength to ceramics using a micro-shear test. Four resin cements were used: a commercial brand cement (RelyX Veneer®) and 3 experimental cements with different types and concentration of photoinitiators. For color analysis, ceramic discs were cemented on bovine dentin specimens to simulate indirect restorations (n=8) and were exposed to UV for 120 h and tested for color alteration using a reflectance spectrophotometer and the CIEL*a*b* system. Data were analyzed by Anova and Tukey's test at 5% significance level. The color test results did not present statistically significant difference for the ∆E for all the studied cements, neither for ∆L, ∆a and ∆b. For the bond strength, all the studied cements showed statistically significant differences to each other, with the highest result for the RelyX Veneer® (29.07 MPa) cement, followed by the cement with CQ (21.74 MPa) and CQ+PPD (19.09 MPa) cement; the lowest result was obtained by the cement using only PPD as a photoinitiator (13.99 MPa). So, based on the studied parameters, PPD was not advantageous as photoinitiator of resin cements, because it showed a low value of bond strength to the ceramics and no superior color stability.

Qualitative and Quantitative Analysis for Facial Complexion in Traditional Chinese Medicine

PubMed Central

Zhao, Changbo; Li, Guo-zheng; Li, Fufeng; Wang, Zhi; Liu, Chang

2014-01-01

Facial diagnosis is an important and very intuitive diagnostic method in Traditional Chinese Medicine (TCM). However, due to its qualitative and experience-based subjective property, traditional facial diagnosis has a certain limitation in clinical medicine. The computerized inspection method provides classification models to recognize facial complexion (including color and gloss). However, the previous works only study the classification problems of facial complexion, which is considered as qualitative analysis in our perspective. For quantitative analysis expectation, the severity or degree of facial complexion has not been reported yet. This paper aims to make both qualitative and quantitative analysis for facial complexion. We propose a novel feature representation of facial complexion from the whole face of patients. The features are established with four chromaticity bases splitting up by luminance distribution on CIELAB color space. Chromaticity bases are constructed from facial dominant color using two-level clustering; the optimal luminance distribution is simply implemented with experimental comparisons. The features are proved to be more distinctive than the previous facial complexion feature representation. Complexion recognition proceeds by training an SVM classifier with the optimal model parameters. In addition, further improved features are more developed by the weighted fusion of five local regions. Extensive experimental results show that the proposed features achieve highest facial color recognition performance with a total accuracy of 86.89%. And, furthermore, the proposed recognition framework could analyze both color and gloss degrees of facial complexion by learning a ranking function. PMID:24967342

Direct push driven in situ color logging tool (CLT): technique, analysis routines, and application

NASA Astrophysics Data System (ADS)

Werban, U.; Hausmann, J.; Dietrich, P.; Vienken, T.

2014-12-01

Direct push technologies have recently seen a broad development providing several tools for in situ parameterization of unconsolidated sediments. One of these techniques is the measurement of soil colors - a proxy information that reveals to soil/sediment properties. We introduce the direct push driven color logging tool (CLT) for real-time and depth-resolved investigation of soil colors within the visible spectrum. Until now, no routines exist on how to handle high-resolved (mm-scale) soil color data. To develop such a routine, we transform raw data (CIEXYZ) into soil color surrogates of selected color spaces (CIExyY, CIEL*a*b*, CIEL*c*h*, sRGB) and denoise small-scale natural variability by Haar and Daublet4 wavelet transformation, gathering interpretable color logs over depth. However, interpreting color log data as a single application remains challenging. Additional information, such as site-specific knowledge of the geological setting, is required to correlate soil color data to specific layers properties. Hence, we exemplary provide results from a joint interpretation of in situ-obtained soil color data and 'state-of-the-art' direct push based profiling tool data and discuss the benefit of additional data. The developed routine is capable of transferring the provided information obtained as colorimetric data into interpretable color surrogates. Soil color data proved to correlate with small-scale lithological/chemical changes (e.g., grain size, oxidative and reductive conditions), especially when combined with additional direct push vertical high resolution data (e.g., cone penetration testing and soil sampling). Thus, the technique allows enhanced profiling by means of providing another reproducible high-resolution parameter for analysis subsurface conditions. This opens potential new areas of application and new outputs for such data in site investigation. It is our intention to improve color measurements by means method of application and data interpretation, useful to characterize vadose layer/soil/sediment characteristics.

Effectiveness of Combination of Dentin and Enamel Layers on the Masking Ability of Porcelain.

PubMed

Boscato, Noéli; Hauschild, Fernando Gabriel; Kaizer, Marina da Rosa; De Moraes, Rafael Ratto

2015-01-01

This study evaluated the masking ability of different porcelain thicknesses and combination of enamel and/or dentin porcelain layers over simulated background dental substrates with higher (A2) and lower (C4) color values. Combination of the enamel (E) and dentin (D) monolayer porcelain disks with different thicknesses (0.5 mm, 0.8 mm, and 1 mm) resulted in the following bilayer groups (n=10): D1E1, D1E0.8; D1E0.5; D0.8E0.8; D0.8E0.5, and D0.5E0.5. CIELAB color coordinates were measured with a spectrophotometer. The translucency parameter of mono and bilayer specimens and the masking ability estimated by color variation (ΔE*ab) of bilayer specimens over simulated dental substrates were evaluated. Linear regression analysis was used to investigate the relationships translucency parameter × ΔE*, translucency parameter × porcelain thickness, and ΔE* × porcelain thickness. Data were analyzed statistically (α= 0.05). Thinner porcelain disks were associated with higher translucency. Porcelain monolayers were considerably more translucent than bilayers (enamel + dentin). Dentin porcelain was less translucent than enamel porcelain with same thickness. ΔE* was always lower when measured over A2 background. Higher ΔE* was observed for the C4 background, indicating poorer masking ability. Increased ΔE* was significantly associated with increased translucency for both backgrounds. Decreased translucency and ΔE* were associated with increased total porcelain thickness or increased dentin thickness for both backgrounds. In conclusion, increased porcelain thickness (particularly increased dentin layer) and increased porcelain opacity resulted in better masking ability of the dental backgrounds.

Least-squares luma-chroma demultiplexing algorithm for Bayer demosaicking.

PubMed

Leung, Brian; Jeon, Gwanggil; Dubois, Eric

2011-07-01

This paper addresses the problem of interpolating missing color components at the output of a Bayer color filter array (CFA), a process known as demosaicking. A luma-chroma demultiplexing algorithm is presented in detail, using a least-squares design methodology for the required bandpass filters. A systematic study of objective demosaicking performance and system complexity is carried out, and several system configurations are recommended. The method is compared with other benchmark algorithms in terms of CPSNR and S-CIELAB ∆E∗ objective quality measures and demosaicking speed. It was found to provide excellent performance and the best quality-speed tradeoff among the methods studied.

Color profiles and stability of acylated and nonacylated anthocyanins as novel pigment sources in a lipstick model: A viable alternative to synthetic colorants.

PubMed

Westfall, Alexandra; Giusti, Mónica

Cosmetics, such as lipstick, can affect an individual's perception of attractiveness and morale. Consumer concern with the safety of synthetic colorants has made the need for alternative natural color sources increasingly urgent. Our goal was to evaluate the feasibility of anthocyanin (ACN) extracts as colorants in lipstick formulations. Lipstick formulations were colored with ACN-rich materials. Accelerated environmental testing typical of the cosmetic industry were used: incubation at 20°, 37°, and 45°C for 12 weeks and temperature abuse cycles between 20°/37°C or -20°/20°C. Color (CIELab) and total monomeric ACN (pH-differential) changes were monitored to determine shelf stability of the product. All formulations exhibited acceptable color for lipsticks. Shelf stability was determined to exceed 2 year based on the accelerated testing conditions. Formulations containing cyanidin as their main ACN were the most stable (elderberry, purple corn, and purple sweet potato). ACNs could be used as suitable alternatives to synthetic colorants in lipid-based topical formulations.

Effects of cold light bleaching on the color stability of composite resins

PubMed Central

Cao, Liqun; Huang, Lijuan; Wu, Meisheng; Wei, Hua; Zhao, Shouliang

2015-01-01

To evaluate the effects of cold light bleaching on the color stability of four restorations using a thermocycling stain challenge. 160 specimens (10 mm in diameter and 2 mm thick) were fabricated from 4 composite resins (Gradia Direct-A, Z350XT, Premisa, and Précis) and divided into 4 subgroups. Color was assessed according to the CIEL*a*b* color scale at baseline, after the first cycle of bleaching, after thermocycling stain challenges, and after the second cycle of bleaching. Mean values were compared using three-way analysis of variance, and multiple comparisons of the mean values were performed using the Tukey-Kramer test. All groups showed significant color changes after stain challenge, the color change was more significant in Gradia Direct and Z350XT than in Premisa and Précis. After the second cycle of bleaching, color mostly recovered to its original values. The color stability of Gradia Direct and Z350XT was inferior to that of Premisa and Précis. The discoloration of composite resin materials can be partly removed after cold light bleaching. PMID:26309549

Evaluation of processing effects on anthocyanin content and colour modifications of blueberry (Vaccinium spp.) extracts: Comparison between HPLC-DAD and CIELAB analyses.

PubMed

Cesa, Stefania; Carradori, Simone; Bellagamba, Giuseppe; Locatelli, Marcello; Casadei, Maria Antonietta; Masci, Alessandra; Paolicelli, Patrizia

2017-10-01

Colour is the first organoleptic property that consumers appreciate of a foodstuff. In blueberry (Vaccinium spp.) fruits, the anthocyanins are the principal pigments determining the colour as well as many of the beneficial effects attributed to this functional food. Commercial blueberry-derived products represent important sources of these healthy molecules all year round. In this study, blueberries were produced into purees comparing two homogenization methods and further heated following different thermal treatments. All the supernatants of the homogenates were monitored for pH. Then, the hydroalcoholic extracts of the same samples were characterized by CIELAB and HPLC-DAD analyses. These analytical techniques provide complementary information on fruit pigments content as a whole and on quali-quantitative profile of the single bioactive colorants. These data could be very interesting to know the best manufacturing procedure to prepare blueberry-derived products, well accepted by the consumers, while maintaining their healthy properties unaltered. Copyright © 2017. Published by Elsevier Ltd.

Effect of glucuronosylation on anthocyanin color stability.

PubMed

Osmani, Sarah Anne; Hansen, Esben Halkjaer; Malien-Aubert, Céline; Olsen, Carl-Erik; Bak, Søren; Møller, Birger Lindberg

2009-04-22

The effect of glucuronosylation on the color stability of anthocyanins was investigated using glucuronosylated anthocyanins isolated from the flower petals of the red daisy (Bellis perennis) or obtained by enzymatic in vitro synthesis using heterologously expressed red daisy glucuronosyltransferase BpUGT94B1. Color stability toward light and heat stress was assessed by monitoring CIELAB color coordinates and stability at pH 7.0 by A(550). Cyanidin-3-O-2''-O-glucuronosylglucoside showed improved color stability in response to light compared to both cyanidin 3-O-glucoside and cyanidin 3-O-2''-O-diglucoside. A similar increase in color stability was not observed following heat treatment. Glucuronosylation did not increase the stability of anthocyanins at pH 7.0 as determined by A(550). To test for a possible effect of glucuronosylation on the color stability of anthocyanins in plant extracts used for food coloration, an elderberry (Sambucus nigra) extract was glucuronosylated in vitro. Glucuronosylation of approximately 50% of total anthocyanins proceeded fast and resulted in increased color stability in response to both heat and light. The data show that glucuronosylation may be used to stabilize industrially used extracts of natural colorants.

Evaluation of the effect of various beverages and food material on the color stability of provisional materials - An in vitro study.

PubMed

Gupta, Gaurav; Gupta, Tina

2011-07-01

THIS STUDY EVALUATED THE COLOR STABILITY OF FOUR PROVISIONAL MATERIALS: 1) Poly-methyl methacrylates (DPI); 2) Bis-acryl composite (ProtempTM II - 3M ESPE); 3) Bis-acryl composite (Systemp® c and b - Ivoclar Vivadent) and 4) Light polymerized composite resin (Revotek LC- GC). The color and color difference of each specimen after immersion in different staining solutions i.e. 1) tea and artificial saliva, 2) coffee and artificial saliva, 3) Pepsi and artificial saliva, 4) turmeric solution and artificial saliva was measured using reflectance spectrophotometer with CIELAB system before immersion and after immersion at 2, 5 ,7 , 10 and 15 days. Revotek LC- GC (light polymerized composite resin) was found to be the most color stable provisional restorative material followed by Protemp II (Bis-acryl composite), Systemp (Bis-acryl composite) and DPI (Methylmethacrylate resin). Turmeric solution had the maximum staining potential followed by coffee, tea and Pepsi.

Evaluation of the effect of various beverages and food material on the color stability of provisional materials – An in vitro study

PubMed Central

Gupta, Gaurav; Gupta, Tina

2011-01-01

Aim: This study evaluated the color stability of four provisional materials: 1) Poly-methyl methacrylates (DPI); 2) Bis-acryl composite (ProtempTM II – 3M ESPE); 3) Bis-acryl composite (Systemp® c and b – Ivoclar Vivadent) and 4) Light polymerized composite resin (Revotek LC- GC). Materials and Methods: The color and color difference of each specimen after immersion in different staining solutions i.e. 1) tea and artificial saliva, 2) coffee and artificial saliva, 3) Pepsi and artificial saliva, 4) turmeric solution and artificial saliva was measured using reflectance spectrophotometer with CIELAB system before immersion and after immersion at 2, 5 ,7 , 10 and 15 days. Results: Revotek LC- GC (light polymerized composite resin) was found to be the most color stable provisional restorative material followed by Protemp II (Bis-acryl composite), Systemp (Bis-acryl composite) and DPI (Methylmethacrylate resin). Turmeric solution had the maximum staining potential followed by coffee, tea and Pepsi. PMID:22025835

Better understanding of digital photography for skin color measurement: With a special emphasis on light characteristics.

PubMed

Seo, Soo Hong; Kim, Jae Hwan; Kim, Ji Woong; Kye, Young Chul; Ahn, Hyo Hyun

2011-02-01

Digital photography can be used to measure skin color colorimetrically when combined with proper techniques. To better understand the settings of digital photography for the evaluation and measurement of skin colors, we used a tungsten lamp with filters and the custom white balance (WB) function of a digital camera. All colored squares on a color chart were photographed with each original and filtered light, analyzed into CIELAB coordinates to produce the calibration method for each given light setting, and compared statistically with reference coordinates obtained using a reflectance spectrophotometer. They were summarized as to the typical color groups, such as skin colors. We compared these results according to the fixed vs. custom WB of a digital camera. The accuracy of color measurement was improved when using light with a proper color temperature conversion filter. The skin colors from color charts could be measured more accurately using a fixed WB. In vivo measurement of skin color was easy and possible with our method and settings. The color temperature conversion filter that produced daylight-like light from the tungsten lamp was the best choice when combined with fixed WB for the measurement of colors and acceptable photographs. © 2010 John Wiley & Sons A/S.

Development of an Image Colorimeter for Noncontact Skin Color Measurement and Application to the Dermatological Treatment

NASA Astrophysics Data System (ADS)

Akimoto, Makio; Chen, Yu; Miyazaki, Michio; Yamashita, Toyonobu; Miyakawa, Michio; Hata, Mieko

The skin is unique as an organ that is highly accessible to direct visual inspection with light. Visual inspection of cutaneous morphology is the mainstay of clinical dermatology, but relies heavily on subjective assessment by the skilled dermatologists. We present an imaging colorimeter of non-contact skin color measuring system and some experimented results using such instrument. The system is comprised by a video camera, light source, a real-time image processing board, magneto optics disk and personal computer which controls the entire system. The CIE-L*a*b* uniform color space is used. This system is used for monitoring of some clinical diagnosis. The instrument is non-contact, easy to operate, and has a high precision unlike the conventional colorimeters. This instrument is useful for clinical diagnoses, monitoring and evaluating the effectiveness of treatment.

Imaging tristimulus colorimeter for the evaluation of color in printed textiles

NASA Astrophysics Data System (ADS)

Hunt, Martin A.; Goddard, James S., Jr.; Hylton, Kathy W.; Karnowski, Thomas P.; Richards, Roger K.; Simpson, Marc L.; Tobin, Kenneth W., Jr.; Treece, Dale A.

1999-03-01

The high-speed production of textiles with complicated printed patterns presents a difficult problem for a colorimetric measurement system. Accurate assessment of product quality requires a repeatable measurement using a standard color space, such as CIELAB, and the use of a perceptually based color difference formula, e.g. (Delta) ECMC color difference formula. Image based color sensors used for on-line measurement are not colorimetric by nature and require a non-linear transformation of the component colors based on the spectral properties of the incident illumination, imaging sensor, and the actual textile color. This research and development effort describes a benchtop, proof-of-principle system that implements a projection onto convex sets (POCS) algorithm for mapping component color measurements to standard tristimulus values and incorporates structural and color based segmentation for improved precision and accuracy. The POCS algorithm consists of determining the closed convex sets that describe the constraints on the reconstruction of the true tristimulus values based on the measured imperfect values. We show that using a simulated D65 standard illuminant, commercial filters and a CCD camera, accurate (under perceptibility limits) per-region based (Delta) ECMC values can be measured on real textile samples.

Color rendering indices in global illumination methods

NASA Astrophysics Data System (ADS)

Geisler-Moroder, David; Dür, Arne

2009-02-01

Human perception of material colors depends heavily on the nature of the light sources used for illumination. One and the same object can cause highly different color impressions when lit by a vapor lamp or by daylight, respectively. Based on state-of-the-art colorimetric methods we present a modern approach for calculating color rendering indices (CRI), which were defined by the International Commission on Illumination (CIE) to characterize color reproduction properties of illuminants. We update the standard CIE method in three main points: firstly, we use the CIELAB color space, secondly, we apply a Bradford transformation for chromatic adaptation, and finally, we evaluate color differences using the CIEDE2000 total color difference formula. Moreover, within a real-world scene, light incident on a measurement surface is composed of a direct and an indirect part. Neumann and Schanda1 have shown for the cube model that interreflections can influence the CRI of an illuminant. We analyze how color rendering indices vary in a real-world scene with mixed direct and indirect illumination and recommend the usage of a spectral rendering engine instead of an RGB based renderer for reasons of accuracy of CRI calculations.

Simulated color: a diagnostic tool for skin lesions like port-wine stain

NASA Astrophysics Data System (ADS)

Randeberg, Lise L.; Svaasand, Lars O.

2001-05-01

A device independent method for skin color visualization has been developed. Colors reconstructed from a reflectance spectrum are presented on a computer screen by sRGB (standard Red Green Blue) color coordinates. The colors are presented as adjacent patches surrounded by a medium grey border. CIELAB color coordinates and CIE (International Commission on Illumination) color difference (Delta) E are computed. The change in skin color due to a change in average blood content or scattering properties in dermis is investigated. This is done by analytical simulations based on the diffusion approximation. It is found that an 11% change in average blood content and a 15% change in scattering properties will give a visible color change. A supposed visibility limit for (Delta) E is given. This value is based on experimental testing and the known properties of the human visual system. This limit value can be used as a tool to determine when to terminate laser treatment of port- wine stain due to low treatment response, i.e. low (Delta) E between treatments. The visualization method presented seems promising for medical applications as port-wine stain diagnostics. The method gives good possibilities for electronic transfer of data between clinics because it is device independent.

Selection of optimal spectral sensitivity functions for color filter arrays.

PubMed

Parmar, Manu; Reeves, Stanley J

2010-12-01

A color image meant for human consumption can be appropriately displayed only if at least three distinct color channels are present. Typical digital cameras acquire three-color images with only one sensor. A color filter array (CFA) is placed on the sensor such that only one color is sampled at a particular spatial location. This sparsely sampled signal is then reconstructed to form a color image with information about all three colors at each location. In this paper, we show that the wavelength sensitivity functions of the CFA color filters affect both the color reproduction ability and the spatial reconstruction quality of recovered images. We present a method to select perceptually optimal color filter sensitivity functions based upon a unified spatial-chromatic sampling framework. A cost function independent of particular scenes is defined that expresses the error between a scene viewed by the human visual system and the reconstructed image that represents the scene. A constrained minimization of the cost function is used to obtain optimal values of color-filter sensitivity functions for several periodic CFAs. The sensitivity functions are shown to perform better than typical RGB and CMY color filters in terms of both the s-CIELAB ∆E error metric and a qualitative assessment.

Improving the sensory and oxidative stability of cooked and chill-stored lamb using dietary rosemary diterpenes.

PubMed

Serrano, Rafael; Ortuño, Jordi; Bañón, Sancho

2014-09-01

Two dietary rosemary extracts (DREs) containing diterpenes (carnosic acid and carnosol at 1:1 and 2:1 w:w) were tested in fattening lambs to stabilize the sensory quality of cooked and chill-stored patties. A total of 63 lambs were fed freely for 80 ± 5 d with a basal diet supplemented or not with DRE. Minced leg meat from each lamb was used to make patty batches. The patties were cooked at 72 ºC for 2 min, aerobically packed, kept at 2 ºC for up to 4 d and then reheated. Sensory traits (color, odor, flavor, and texture), CIELab color, and lipid oxidation (assessed as TBARS) were determined. In a first experiment, the lamb diet was supplemented with 600 mg of 1:1-DRE or 2:1-DRE kg(-1) feed. The 1:1-DRE diet delayed discoloration, flavor deterioration, and rancidity, while the 2:1-DRE diet was ineffective in this respect. In a second experiment, 4 supplementation levels of 1:1-DRE (0, 200, 400, and 600 mg kg(-1) feed) were compared. Flavor deterioration was delayed when the lamb diet was supplemented with at least 400 mg 1:1-DRE kg(-1) feed. The effects of the diet on the odor, flavor, and color were corroborated by differences in TBARS and CIELab. The results obtained suggest that rosemary diterpenes and/or their active secondary compounds deposited in muscle can act as endogenous antioxidants in cooked lamb. The carnosol intake seems crucial in the antioxidant actions achieved through DRE. The use of rosemary antioxidants in animal feeding would allow meat-based dishes to be preserved longer without adding preservatives. © 2014 Institute of Food Technologists®

Effect of different photoinitiators and reducing agents on cure efficiency and color stability of resin-based composites using different LED wavelengths.

PubMed

de Oliveira, Dayane Carvalho Ramos Salles; Rocha, Mateus Garcia; Gatti, Alexandre; Correr, Americo Bortolazzo; Ferracane, Jack Liborio; Sinhoret, Mario Alexandre Coelho

2015-12-01

To evaluate the effect of photoinitiators and reducing agents on cure efficiency and color stability of resin-based composites using different LED wavelengths. Model resin-based composites were associated with diphenyl(2,4,6-trimethylbenzoyl) phosphine oxide (TPO), phenylbis(2,4,6-trimethylbenzoyl) phosphine oxide (BAPO) or camphorquinone (CQ) associated with 2-(dimethylamino) ethyl methacrylate (DMAEMA), ethyl 4-(dimethyamino) benzoate (EDMAB) or 4-(N,N-dimethylamino) phenethyl alcohol (DMPOH). A narrow (Smartlite, Dentisply) and a broad spectrum (Bluephase G2, Ivoclar Vivadent) LEDs were used for photo-activation (20 J/cm(2)). Fourier transform infrared spectroscopy (FT-IR) was used to evaluate the cure efficiency for each composite, and CIELab parameters to evaluated color stability (ΔE00) after aging. The UV-vis absorption spectrophotometric analysis of each photoinitiator and reducing agent was determined. Data were analyzed using two-way ANOVA and Tukey's test for multiple comparisons (α=0.05). Higher cure efficiency was found for type-I photoinitiators photo-activated with a broad spectrum light, and for CQ-systems with a narrow band spectrum light, except when combined with an aliphatic amine (DMAEMA). Also, when combined with aromatic amines (EDMAB and DMPOH), similar cure efficiency with both wavelength LEDs was found. TPO had no cure efficiency when light-cured exclusively with a blue narrowband spectrum. CQ-systems presented higher color stability than type-I photoinitiators, especially when combined with DMPOH. After aging, CQ-based composites became more yellow and BAPO and TPO lighter and less yellow. However, CQ-systems presented higher color stability than type-I photoinitiators, as BAPO- and TPO-, despite their higher cure efficiency when photo-activated with corresponding wavelength range. Color matching is initially important, but color change over time will be one of the major reasons for replacing esthetic restorations; despite the less yellowing of these alternative photoinitiators, camphorquinone presented higher color stability. Copyright © 2015 Elsevier Ltd. All rights reserved.

Darkfield reflection visible microspectroscopy equipped with a color mapping system of a brown altered granite.

PubMed

Onga, Chie; Nakashima, Satoru

2014-01-01

Visible darkfield reflectance spectroscopy equipped with a color mapping system has been developed and applied to a brown-colored Rokko granite sample. Sample reflectance spectra converted to Kubelka-Munk (KM) spectra show similar features to goethite and lepidocrocite. Raman microspectroscopy on the granite sample surface confirms the presence of these minerals. Here, L*a*b* color values (second Commission Internationale d'Eclairage [CIELab] 1976 color space) were determined from the sample reflection spectra. Grey, yellow, and brown zones of the granite show different L*, a*, and b* values. In the a*-b* diagram, a* and b* values in the grey and brown zones are on the lepidocrocite/ferrihydrite trends, but their values in the brown zone are larger than those in the grey zone. The yellow zone shows data points close to the goethite trend. Iron (hydr)oxide-rich areas can be visualized by means of large a* and b* values in the L*, a*, and b* maps. Although the present method has some problems and limitations, the visible darkfield reflectance spectroscopy can be a useful method for colored-material characterization.

Color image enhancement based on particle swarm optimization with Gaussian mixture

NASA Astrophysics Data System (ADS)

Kattakkalil Subhashdas, Shibudas; Choi, Bong-Seok; Yoo, Ji-Hoon; Ha, Yeong-Ho

2015-01-01

This paper proposes a Gaussian mixture based image enhancement method which uses particle swarm optimization (PSO) to have an edge over other contemporary methods. The proposed method uses the guassian mixture model to model the lightness histogram of the input image in CIEL*a*b* space. The intersection points of the guassian components in the model are used to partition the lightness histogram. . The enhanced lightness image is generated by transforming the lightness value in each interval to appropriate output interval according to the transformation function that depends on PSO optimized parameters, weight and standard deviation of Gaussian component and cumulative distribution of the input histogram interval. In addition, chroma compensation is applied to the resulting image to reduce washout appearance. Experimental results show that the proposed method produces a better enhanced image compared to the traditional methods. Moreover, the enhanced image is free from several side effects such as washout appearance, information loss and gradation artifacts.

Preparation of ruby red glasses from gold nanoparticles: Influence of stannic oxide

NASA Astrophysics Data System (ADS)

Ruangtaweep, Y.; A-nupan, P.; Kaewkhao, J.

2014-03-01

In this work, effects of stannic oxide concentration to red glass prepared from gold nanoparticle (AuNPs) have been investigated. The glasses were fabricated by conventional melt quench method using SiO2, CaO, K2CO3, Na2CO3, SeO2, AuNPs and vary stannic oxide concentration by 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5 % by weight. The result found that, the red colors of glasses were obtained from gold nanoparticles at 0.1, 0.2 and 0.5 % of stannic oxide. At 0.0, 0.3 and 0.4 % are show purple-blue colors. The results reflecting that the particle size of gold particle in glass matrices at 0.1, 0.2 and 0.5 % of stannic oxide are smaller than 0.3 and 0.4 %. The color of glasses were confirmed by uv-visible spectrophotometer and color coordinate in CIEL*a*b*.

Bayer Demosaicking with Polynomial Interpolation.

PubMed

Wu, Jiaji; Anisetti, Marco; Wu, Wei; Damiani, Ernesto; Jeon, Gwanggil

2016-08-30

Demosaicking is a digital image process to reconstruct full color digital images from incomplete color samples from an image sensor. It is an unavoidable process for many devices incorporating camera sensor (e.g. mobile phones, tablet, etc.). In this paper, we introduce a new demosaicking algorithm based on polynomial interpolation-based demosaicking (PID). Our method makes three contributions: calculation of error predictors, edge classification based on color differences, and a refinement stage using a weighted sum strategy. Our new predictors are generated on the basis of on the polynomial interpolation, and can be used as a sound alternative to other predictors obtained by bilinear or Laplacian interpolation. In this paper we show how our predictors can be combined according to the proposed edge classifier. After populating three color channels, a refinement stage is applied to enhance the image quality and reduce demosaicking artifacts. Our experimental results show that the proposed method substantially improves over existing demosaicking methods in terms of objective performance (CPSNR, S-CIELAB E, and FSIM), and visual performance.

CIE colorimetric system fails to calculate the chroma of a Nd:YAG crystal under the fluorescent illuminant F7

NASA Astrophysics Data System (ADS)

Liu, Yan; Chen, Qinghan; Bu, Xianhui; Feng, Pingyun

2002-06-01

The rare earth element neodymium doped yttrium aluminum garnet (Nd:YAG) is a laser crystal widely used for producing laser in the infrared range. Neodymium causes many characteristic absorption peaks in the transmittance spectrum of the Nd:YAG crystal in the visible range. The crystal appears pink under daylight and incandescent light, and colorless under fluorescent light. The colorimetric calculation results of chroma under the CIE standard fluorescent illuminant F7 do not agree with the color appearance under fluorescent light. The calculated chroma values should be near zero to agree with a colorless appearance, but it is actually 11.79 in the CIELAB color space. This failure of the colorimetric calculation is caused by the color matching functions of the CIE colorimetric observers. The color matching functions do not agree with the spectral sensitivity curves of the human eye, especially the x(λ) function does not matches the spectral sensitivity curve of the long wavelength cone photoreceptors.

Spoilage of sous vide cooked salmon (Salmo salar) stored under refrigeration.

PubMed

Díaz, P; Garrido, M D; Bañón, S

2011-02-01

The spoilage of Sous Vide 'SV' cooked salmon stored under refrigeration was studied. Samples were packaged under vacuum in polyamide-polypropylene pouches, cooked at an oven temperature/time of 80 (°)C/45 min, quickly chilled at 3 (°)C and stored at 2 (°)C for 0, 5 or 10 weeks for catering use. Microbial (aerobic and anaerobic psychrotrophs, lactic acid bacteria, molds and yeasts and Enterobacteriaceae), physical-chemical (pH, water activity, TBARS, acidity, L*a*b* color, texture profile analysis and shear force) and sensory (appearance, odor, flavor, texture and overall quality) parameters were determined. SV processing prevented the growth of aerobic and anaerobic psychrotrophs, lactic acid bacteria, molds and yeasts and Enterobacteriaceae. There were no relevant changes in pH, water activity, TBARS, CIELab color associated with cooked salmon spoilage. Instrumental texture data were contradictory. Slight decrease in lactic acid levels was found. In contrast, the SV cooked salmon suffered considerable sensory deterioration during its refrigerated storage, consisting of severe losses of cooked salmon odor and flavor, slight rancidity, discoloration associated with white precipitation, and moderates softness, and loss of chewiness and juiciness. No acidification, putrefaction or relevant rancidity was detected. The sensory spoilage preceded microbiological and physical-chemical spoilage, suggesting that microbiological quality alone may overestimate the shelf life of SV cooked salmon.

Color-rendering indices in global illumination methods

NASA Astrophysics Data System (ADS)

Geisler-Moroder, David; Dür, Arne

2009-10-01

Human perception of material colors depends heavily on the nature of the light sources that are used for illumination. One and the same object can cause highly different color impressions when lit by a vapor lamp or by daylight, respectively. On the basis of state-of-the-art colorimetric methods, we present a modern approach for the calculation of color-rendering indices (CRI), which were defined by the International Commission on Illumination (CIE) to characterize color reproduction properties of illuminants. We update the standard CIE method in three main points: first, we use the CIELAB color space; second, we apply a linearized Bradford transformation for chromatic adaptation; and finally, we evaluate color differences using the CIEDE2000 total color difference formula. Moreover, within a real-world scene, light incident on a measurement surface is composed of a direct and an indirect part. Neumann and Schanda [Proc. CGIV'06 Conf., Leeds, UK, pp. 283-286 (2006)] have shown for the cube model that diffuse interreflections can influence the CRI of a light source. We analyze how color-rendering indices vary in a real-world scene with mixed direct and indirect illumination and recommend the usage of a spectral rendering engine instead of an RGB-based renderer for reasons of accuracy of CRI calculations.

Fiber optics reflectance spectroscopy (45°x: 45°) for color analysis of dental composite.

PubMed

Gargano, Marco; Ludwig, Nicola; Federighi, Veronica; Sykes, Ros; Lodi, Giovanni; Sardella, Andrea; Carrassi, Antonio; Varoni, Elena M

2016-08-01

To evaluate the application of a fiber optic reflectance spectroscopy (FORS) prototype probe for 45°x: 45° FORS for determining color of dental materials. A portable spectrophotometer with a highly manageable fiber optics co-axial probe was used to apply 45°x: 45° FORS for color matching in restorative dentistry. The color coordinates in CIELAB space of two dental shade guides and of the corresponding photopolymerized composites were collected and compared. The 45°x: 45° FORS with the co-axial probe (test system), the integrating sphere spectroscopy (reference system) and a commercial dental colorimeter (comparator system) were used to collect data and calculate color differences (ΔE and ΔE00). FORS system displayed high repeatability, reproducibility and accuracy. ΔE and ΔE00 values between the shade-guide, each other, and the corresponding composites resulted above the clinically acceptable limit. The 45°x: 45° FORS test system demonstrated suitable in vitro performance for dental composite color evaluation. 45°x: 45° fiber optic reflectance spectroscopy allows reliable color analysis of small surfaces of dental composites, favoring the color matching of material with the closely surrounding dental tissue, and confirming significant color differences between shade guide tabs and photo-polymerized composites.

Quality and microbial safety evaluation of new isotonic beverages upon thermal treatments.

PubMed

Gironés-Vilaplana, Amadeo; Huertas, Juan-Pablo; Moreno, Diego A; Periago, Paula M; García-Viguera, Cristina

2016-03-01

In the present study, it was evaluated how two different thermal treatments (Mild and Severe) may affect the anthocyanin content, antioxidant capacity (ABTS(+), DPPH, and FRAP), quality (CIELAB colour parameters), and microbiological safety of a new isotonic drink made of lemon and maqui berry over a commercial storage simulation using a shelf life of 56days at two preservation temperature (7°C and 37°C). Both heat treatments did not affect drastically the anthocyanins content and their percentage of retention. The antioxidant capacity, probably because of the short time, was also not affected. The CIELAB colour parameters were affected by the heat, although the isotonic drinks remained with attractive red colour during shelf life. From a microbiological point of view, the Mild heat treatment with storage at 7°C is the ideal for the preservation of microbial growth, being useful for keeping the quality and safety of beverages in commercial life. Copyright © 2015. Published by Elsevier Ltd.

Effect of bleaching on color change and surface topography of composite restorations.

PubMed

Pruthi, Gunjan; Jain, Veena; Kandpal, H C; Mathur, Vijay Prakash; Shah, Naseem

2010-01-01

This study was conducted to determine the effect of 15% carbamide peroxide bleaching agent on color change and surface topography of different composite veneering materials (Filtek Z350 (3M ESPE), Esthet X (Dentsply India), and Admira (Voco, Germany). Methods. 30 samples were fabricated for evaluation of color change using CIELAB color system and Gonioreflectometer (GK 311/M, ZEISS). 45 disc-shaped specimens were made for evaluation of surface topography after bleaching (Nupro White Gold; Dentsply) using SEM. Statistical analysis. One way ANOVA and Multiple comparison tests were used to analyze the data. Statistical significance was declared if the P value was .05 or less. Results and conclusion. All the specimens showed significant discoloration (ΔE > 3.3) after their immersion in solutions representing food and beverages. The total color change after bleaching as compared to baseline color was significant in Filtek Z350 (P = .000) and Esthet X (P = .002), while it was insignificant for Admira (P = .18). Esthet X showed maximum surface roughness followed by Admira and Filtek Z350. Bleaching was effective in reducing the discoloration to a clinically acceptable value in all the three groups (ΔE < 3.3).

Evaluation of Discoloration Removal by Polishing Resin Composites Submitted to Staining in Different Drink Solutions

PubMed Central

Spina, Denis Roberto Falcão; Grossi, João Ricardo Almeida; Cunali, Rafael Schlögel; Baratto Filho, Flares; da Cunha, Leonardo Fernandes; Gonzaga, Carla Castiglia; Correr, Gisele Maria

2015-01-01

The aim of this study was to evaluate the discoloration effects of water, cola-based soft drink, coffee, and wine on resin composites used in restorative dentistry and the possibility of removing the stain with chair side manual polishing. The A2 shade of three materials was tested. Disc specimens were prepared. A spectrophotometer was used to measure the baseline CIE-Lab color parameters of each material (n=10) 24 hours after sample preparation. Samples were then immersed in a cola-based soft drink, coffee, or wine for 1 hour every day, for 30 days. For the remaining hours, the specimens were stored in distilled water. In the control group, the specimens were immersed in water for the whole period. The color differences (ΔE) were calculated after 7 and 30 days of storage, and after polishing with coarse Sof-Lex discs, and analyzed by two-way ANOVA with repeated measures and Tukey's HSD test (α=0.05). Luna presented higher ΔE values (3.41)a followed by Durafill (2.82)b and Herculite (2.24)c. For the drink solutions, ΔE values were higher for wine (4.40)a followed by coffee (2.59)b and for cola-based soft drink (2.23)c and water (2.13)c which were statistically similar. For time, ΔE values were higher for 30 days (3.97)a and then for 7 days (2.48)b and after polishing (2.04)c. The results indicate that color stability is material dependent. The types of drinks that patients consume also influence the color stability of restorative materials. PMID:27347551

Effect of light irradiation on tooth whitening: enamel microhardness and color change.

PubMed

Gomes, Mauricio Neves; Francci, Carlos; Medeiros, Igor Studart; De Godoy Froes Salgado, Nívea Regina; Riehl, Heraldo; Marasca, José Milton; Muench, Antônio

2009-01-01

The aim of this study was to evaluate the influence of light exposure associated with 35% hydrogen peroxide (Pola Office, SDI, Melbourne, Vic., Australia) or 15% hydrogen peroxide (BriteSmile, Discus, Culver City, CA, USA) on the microhardness and color changes of bovine enamel. Experimental groups were Britesmile + Light (BL) (15% hydrogen peroxide + plasm arc; 4 x 20 minutes), Britesmile + No Light (BN) (BL, no light), Pola office + Light (PL) (35% hydrogen peroxide + LED; 4 x 8 minutes), and Pola office + No light (PN) (PL, no light). Color changes (DeltaE) and the CIELAB (Commission Internationale de l' Eclairage, L* a* b* color system) parameters (L*, a*, and b*) were assessed with a spectrophotometer before (B), immediately (A), 1 day and 7 days after bleaching. The microhardness was measured before (B) and after (A), the obtained data were submitted to a two-way analysis of variance, and DeltaE were submitted to t-test for each period. Only Pola Office, in which the peroxide is associated with the light, improved DeltaE when evaluated immediately after bleaching (p < 0.001). Light exposure did not influence DeltaE after 1 day or 7 days for either bleaching system. The enamel microhardness was not altered after bleaching for BriteSmile. However, enamel microhardness was reduced after bleaching for Pola Office, 283 MPa (+/-21) and 265 MPa (+/-27), respectively. It was concluded that these two bleaching systems were efficient regardless of the light systems used. However, the 35% hydrogen peroxide altered the enamel microhardness. CLINICAL SIGNIFICANCE Enamel microhardness was affected by a 35% hydrogen peroxide in-office bleaching therapy. Moreover, the in-office bleaching outcome was not improved by using the light associated with systems tested in this study. (J Esthet Restor Dent 21:387-396, 2009).

A True-Color Sensor and Suitable Evaluation Algorithm for Plant Recognition

PubMed Central

Schmittmann, Oliver; Schulze Lammers, Peter

2017-01-01

Plant-specific herbicide application requires sensor systems for plant recognition and differentiation. A literature review reveals a lack of sensor systems capable of recognizing small weeds in early stages of development (in the two- or four-leaf stage) and crop plants, of making spraying decisions in real time and, in addition, are that are inexpensive and ready for practical use in sprayers. The system described in this work is based on free cascadable and programmable true-color sensors for real-time recognition and identification of individual weed and crop plants. The application of this type of sensor is suitable for municipal areas and farmland with and without crops to perform the site-specific application of herbicides. Initially, databases with reflection properties of plants, natural and artificial backgrounds were created. Crop and weed plants should be recognized by the use of mathematical algorithms and decision models based on these data. They include the characteristic color spectrum, as well as the reflectance characteristics of unvegetated areas and areas with organic material. The CIE-Lab color-space was chosen for color matching because it contains information not only about coloration (a- and b-channel), but also about luminance (L-channel), thus increasing accuracy. Four different decision making algorithms based on different parameters are explained: (i) color similarity (ΔE); (ii) color similarity split in ΔL, Δa and Δb; (iii) a virtual channel ‘d’ and (iv) statistical distribution of the differences of reflection backgrounds and plants. Afterwards, the detection success of the recognition system is described. Furthermore, the minimum weed/plant coverage of the measuring spot was calculated by a mathematical model. Plants with a size of 1–5% of the spot can be recognized, and weeds in the two-leaf stage can be identified with a measuring spot size of 5 cm. By choosing a decision model previously, the detection quality can be increased. Depending on the characteristics of the background, different models are suitable. Finally, the results of field trials on municipal areas (with models of plants), winter wheat fields (with artificial plants) and grassland (with dock) are shown. In each experimental variant, objects and weeds could be recognized. PMID:28786922

A True-Color Sensor and Suitable Evaluation Algorithm for Plant Recognition.

PubMed

Schmittmann, Oliver; Schulze Lammers, Peter

2017-08-08

Plant-specific herbicide application requires sensor systems for plant recognition and differentiation. A literature review reveals a lack of sensor systems capable of recognizing small weeds in early stages of development (in the two- or four-leaf stage) and crop plants, of making spraying decisions in real time and, in addition, are that are inexpensive and ready for practical use in sprayers. The system described in this work is based on free cascadable and programmable true-color sensors for real-time recognition and identification of individual weed and crop plants. The application of this type of sensor is suitable for municipal areas and farmland with and without crops to perform the site-specific application of herbicides. Initially, databases with reflection properties of plants, natural and artificial backgrounds were created. Crop and weed plants should be recognized by the use of mathematical algorithms and decision models based on these data. They include the characteristic color spectrum, as well as the reflectance characteristics of unvegetated areas and areas with organic material. The CIE-Lab color-space was chosen for color matching because it contains information not only about coloration (a- and b-channel), but also about luminance (L-channel), thus increasing accuracy. Four different decision making algorithms based on different parameters are explained: (i) color similarity (ΔE); (ii) color similarity split in ΔL, Δa and Δb; (iii) a virtual channel 'd' and (iv) statistical distribution of the differences of reflection backgrounds and plants. Afterwards, the detection success of the recognition system is described. Furthermore, the minimum weed/plant coverage of the measuring spot was calculated by a mathematical model. Plants with a size of 1-5% of the spot can be recognized, and weeds in the two-leaf stage can be identified with a measuring spot size of 5 cm. By choosing a decision model previously, the detection quality can be increased. Depending on the characteristics of the background, different models are suitable. Finally, the results of field trials on municipal areas (with models of plants), winter wheat fields (with artificial plants) and grassland (with dock) are shown. In each experimental variant, objects and weeds could be recognized.

Effect of the Polishing Procedures on Color Stability and Surface Roughness of Composite Resins

PubMed Central

Schmitt, Vera Lucia; Puppin-Rontani, Regina Maria; Naufel, Fabiana Scarparo; Nahsan, Flávia Pardo Salata; Alexandre Coelho Sinhoreti, Mário; Baseggio, Wagner

2011-01-01

Objectives. To evaluate the polishing procedures effect on color stability and surface roughness of composite resins. Methods. Specimens were distributed into 6 groups: G1: Filtek Supreme XT + PoGo; G2: Filtek Supreme XT + Sof-Lex; G3: Filtek Supreme XT + no polishing; G4: Amelogen + PoGo; G5: Amelogen + Sof-Lex.; G6: Amelogen + no polishing. Initial color values were evaluated using the CIELab scale. After polishing, surface roughness was evaluated and the specimens were stored in coffee solution at 37°C for 7 days. The final color measurement and roughness were determined. Results. Sof-Lex resulted in lower staining. Amelogen showed the highest roughness values than Filtek Supreme on baseline and final evaluations regardless of the polishing technique. Filtek Supreme polished with PoGo showed the lowest roughness values. All groups presented discoloration after storage in coffee solution, regardless of the polishing technique. Conclusion. Multiple-step polishing technique provided lower degree of discoloration for both composite resins. The final surface texture is material and technique dependent. PMID:21991483

Adaptive color halftoning for minimum perceived error using the blue noise mask

NASA Astrophysics Data System (ADS)

Yu, Qing; Parker, Kevin J.

1997-04-01

Color halftoning using a conventional screen requires careful selection of screen angles to avoid Moire patterns. An obvious advantage of halftoning using a blue noise mask (BNM) is that there are no conventional screen angle or Moire patterns produced. However, a simple strategy of employing the same BNM on all color planes is unacceptable in case where a small registration error can cause objectionable color shifts. In a previous paper by Yao and Parker, strategies were presented for shifting or inverting the BNM as well as using mutually exclusive BNMs for different color planes. In this paper, the above schemes will be studied in CIE-LAB color space in terms of root mean square error and variance for luminance channel and chrominance channel respectively. We will demonstrate that the dot-on-dot scheme results in minimum chrominance error, but maximum luminance error and the 4-mask scheme results in minimum luminance error but maximum chrominance error, while the shift scheme falls in between. Based on this study, we proposed a new adaptive color halftoning algorithm that takes colorimetric color reproduction into account by applying 2-mutually exclusive BNMs on two different color planes and applying an adaptive scheme on other planes to reduce color error. We will show that by having one adaptive color channel, we obtain increased flexibility to manipulate the output so as to reduce colorimetric error while permitting customization to specific printing hardware.

Properties of a color-changeable chewing gum used to evaluate masticatory performance.

PubMed

Hama, Yohei; Kanazawa, Manabu; Minakuchi, Shunsuke; Uchida, Tatsuro; Sasaki, Yoshiyuki

2014-04-01

To clarify the basic properties of a color-changeable chewing gum to determine its applicability to evaluations of masticatory performance under different types of dental status. Ten participants with natural dentition aged 26-30 years chewed gum that changes color during several chewing strokes over five repetitions. Changes in color were assessed using a colorimeter, and then L*, a*, and b* values in the CIELAB color system were quantified. Relationships between chewing progression and color changes were assessed using regression analysis and the reliability of color changes was assessed using intraclass correlation coefficients. We then measured 42 dentate participants (age, 22-31 years) and 47 complete denture wearers (age, 44-90 years) to determine the detectability of masticatory performance under two types of dental status. Regression between the number of chewing strokes and the difference between two colors was non-linear. The intraclass correlation coefficients were highest between 60 and 160 chewing strokes. Dentate and edentulous groups significantly differed (Wilcoxon rank sum test) and values were widely distributed within each group. The color of the chewing gum changed over a wide range, which was sufficient to evaluate the masticatory performance of individuals with natural dentition and those with complete dentures. Changes in the color values of the gum reliably reflected masticatory performance. These findings indicate that the color-changeable chewing gum will be useful for evaluating masticatory performance under any dental status. Copyright © 2014 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Image quality assessment by preprocessing and full reference model combination

NASA Astrophysics Data System (ADS)

Bianco, S.; Ciocca, G.; Marini, F.; Schettini, R.

2009-01-01

This paper focuses on full-reference image quality assessment and presents different computational strategies aimed to improve the robustness and accuracy of some well known and widely used state of the art models, namely the Structural Similarity approach (SSIM) by Wang and Bovik and the S-CIELAB spatial-color model by Zhang and Wandell. We investigate the hypothesis that combining error images with a visual attention model could allow a better fit of the psycho-visual data of the LIVE Image Quality assessment Database Release 2. We show that the proposed quality assessment metric better correlates with the experimental data.

Influence of surface sealing on color stability and roughness of composite submitted to ultraviolet-accelerated aging.

PubMed

Catelan, Anderson; Suzuki, Thaís Yumi Umeda; Becker, Francisco; Briso, André Luiz Fraga; Dos Santos, Paulo Henrique

2017-05-01

In the present study, we evaluated the influence of surface sealing on color stability and surface roughness of a composite resin after accelerated artificial aging. Thirty-two specimens of a composite were prepared. After 24 h, the specimens were polished and divided into four groups (n = 8), according to the surface sealant used, including the control, which had no sealant application. Baseline color was measured according to the CIELab system using a reflection spectrophotometer. Surface roughness was determined using a profilometer with a cut-off of 0.25 mm. After these tests, specimens were aged for 252 h in an ultraviolet (UV)-accelerated aging chamber. Color stability was determined by difference between coordinates obtained before and after the aging procedure. Data of color change and roughness were evaluated by anova and Fisher's exact test (α = 0.05). The results showed that the unsealed group had the highest color change compared to other groups (P = 0.0289), and there was no significant difference between groups sealed with surface sealant (P > 0.05). The artificial aging caused an increase in roughness values independent of the experimental group studied (P = 0.0015). The sealed composites showed lower color change after UV aging, but all groups showed clinically-acceptable color change, and only liquid polish decreased roughness. © 2016 John Wiley & Sons Australia, Ltd.

Kinetics of color development of melanoidins formed from fructose/amino acid model systems.

PubMed

Echavarría, A P; Pagán, J; Ibarz, A

2014-03-01

The formation of soluble melanoidins from a single combination of sugar (fructose) and amino acid model systems were evaluated kinetically. The selected amino acids, commonly found in apple juice and highly reactive in the Maillard reaction, were asparagine, aspartic acid, and glutamic acid. The effect of these reagents and the treatment at different temperatures (50 , 85 , and 100 ) during 96 h on the color intensity of the melanoidin formed was measured by absorbance at different wavelengths (280, 325, 405, and 420 nm). The absorbance of the melanoidin formed from all model systems was located on the wavelength of 405 nm, that is, the area of the visible spectrum close to the UV region. The color of the melanoidins was directly measured using the CIELAB color space system. A first-order kinetic model was applied to the evolution of the ΔE * (color difference) and L * (lightness) of the color. The fructose/aspartic acid model system values of a * (redness) and b * (yellowness) were found in the brown-red zone. Therefore, the color development of the melanoidins was influenced by the type of amino acid and temperature. Especially, it is thought that the a * and b * values can be used to explain the differences among the amino acids in the color development of melanoidins.

Effect on White Grape Must of Multiflora Bee Pollen Addition during the Alcoholic Fermentation Process.

PubMed

Amores-Arrocha, Antonio; Roldán, Ana; Jiménez-Cantizano, Ana; Caro, Ildefonso; Palacios, Víctor

2018-05-31

The aim of the present study was to compare and analyze the impact of using bee pollen doses (0.1, 0.25, 1, 5, 10 and 20 g/L) as activator in the alcoholic fermentation process of Palomino fino and Riesling wines. In this regard, its influence on the musts composition, the fermentative kinetics, the evolution of the populations of Saccharomyces cerevisiae , the evolution of yeast-assimilable nitrogen and physico-chemical characteristics of final wines has been analyzed. Bee pollen addition produces significant increases in yeast-assimilable nitrogen and maximum yeasts population and exponential velocity reached during alcoholic fermentation. Bee pollen showed an important effect on yeast survival during the death phase. Final wines showed significantly increase in volatile acidity above doses higher than 10 g/L and Comisión Internacional de L'Eclairage parameters (CIELab), color intensity and Abs 420 nm, from 1 g/L. Therefore, pollen could be used as fermentative activator for the alcoholic fermentation of white wines applying doses below of 1 g/L.

Accurate chromatic control and color rendering optimization in LED lighting systems using junction temperature feedback

NASA Astrophysics Data System (ADS)

Sisto, Marco Michele; Gauvin, Jonny

2014-09-01

Accurate color control of LED lighting systems is a challenging task: noticeable chromaticity shifts are commonly observed in mixed-color and phosphor converted LEDs due to intensity dimming. Furthermore, the emitted color varies with the LED temperature. We present a novel color control method for tri-chromatic and tetra-chromatic LEDs, which enable to set and maintain the LED emission at a target color, or combination of correlated color temperature (CCT) and intensity. The LED color point is maintained over variations in the LED junctions' temperatures and intensity dimming levels. The method does not require color feedback sensors, so to minimize system complexity and cost, but relies on estimation of the LED junctions' temperatures from the junction voltages. If operated with tetra-chromatic LEDs, the method allows meeting an additional optimization criterion: for example, the maximization of a color rendering metric like the Color Rendering Index (CRI) or the Color Quality Scale (CQS), thus providing a high quality and clarity of colors on the surface illuminated by the LED. We demonstrate the control of a RGBW LED at target D65 white point with CIELAB color difference metric triangle;a,bE < 1 for simultaneous variations of flux from approximately 30 lm to 100 lm and LED heat sink temperature from 25°C to 58°C. In the same conditions, we demonstrate a CCT error <1%. Furthermore, the method allows varying the LED CCT from 5500K to 8000K while maintaining luminance within 1% of target. Further work is ongoing to evaluate the stability of the method over LED aging.

Effect of metal opaquer on the final color of 3 ceramic crown types on 3 abutment configurations.

PubMed

Arif, Rabia; Yilmaz, Burak; Mortazavi, Aras; Ozcelik, Tuncer B; Johnston, William M

2018-04-30

The effect of a recently introduced metal opaquer when used to mask the color of a titanium abutment under ceramic crown systems is unknown. The purpose of this study was to compare the color coordinates of 3 ceramic crown types-characterized monolithic lithium disilicate (LDC) (IPS e.max; Ivoclar Vivadent AG), layered lithium disilicate (LDL) (IPS e.max; Ivoclar Vivadent AG), and layered zirconia (ZL) (H.C. Starck)-on 3 abutment configurations, nonopaqued titanium (Ti), resin opaqued titanium (Op), and zirconia (Zir). In addition, the color differences (CIEDE2000) were evaluated among the 3 crown types on 3 different abutment substrates. Ten Ti disks (10×1 mm) were fabricated with computer-aided design and computer-aided manufacturing (CAD-CAM) to represent the Ti abutments. Five Ti specimens were opaqued (Op) (whiteMetal Opaquer wMO; Blue Sky Bio), and 5 were not opaqued (Ti). Ten zirconia disks were fabricated with CAD-CAM and sintered (10×1.2 mm). Five disks were used as backings to represent Zir abutments, and 5 disks were layered with 1 mm of porcelain (B1, IPS e.Max Ceram; Ivoclar Vivadent AG) to represent layered zirconia crowns (ZL). Ten lithium disilicate plates (14×14×1.2 mm) were sectioned from CAD blocks (B1 IPS e.Max CAD; Ivoclar Vivadent AG). Five plates were layered with the same porcelain (B1, 1 mm), and 5 plates were surface characterized and glazed. An LDL crown on a Zir abutment configuration was used as the control. The 3 simulated crown types (n=5) were optically connected to each of the 3 abutment types, and the color of the 9 groups was measured using a spectroradiometer. Measured data were reported in CIELab coordinates. CIELab data were used to calculate color differences between the control and the 8 experimental groups. Color data were summarized for each group, and analyzed by repeated-measures ANOVA. For pairwise comparisons, a Bonferroni correction of t tests was used, and for interpretive analysis of resulting color difference data, a 1-way ANOVA and subsequent Tukey testing for pairwise comparisons were used. The statistical significance of the analysis of color coordinates was found to be P≤.002. Although 3-way interaction was not found to be significant (P=.335), all three 2-way interactions of the main effects were found to be significant (P≤.002). All crown types on the Zir abutment revealed color differences from the control group. The color differences of the crown types on the Op and Zir abutment configurations compared with the control (LDL/Zir) were not (P>.05) statistically different. Colors of tested crown systems on Ti backing were each unacceptably different from the control group. Colors of these systems on zirconia backing were not perceivably different. Use of opaquer on titanium backing resulted in a small color difference from the control group (P>.05) for each crown system, demonstrating that it may be used to prevent the unfavorable metal show-through that can influence the final color of all ceramic crown systems tested. Copyright © 2018 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Color stability of different denture teeth materials: an in vitro study.

PubMed

Mutlu-Sagesen, L; Ergün, G; Ozkan, Y; Bek, B

2001-09-01

The aim of this in vitro study was to compare the color stability of commercially available porcelain, reinforced acrylic, and conventional acrylic denture teeth materials used in removable prostheses. Two brands of porcelain (Unilux-Enta Lactona-Holland and Vivoperl-Ivoclar-Liechtenstein), 2 brands of reinforced acrylic (Optodent-Bayer-Germany and Ivolek-Ivoclar-Liechtenstein), and 2 brands of conventional acrylic (Isodent-Güney Diş Deposu-Turkey and Samed-Turkey), were made, for a total of 6 different denture teeth groups. Denture teeth were subjected to 3 staining solutions (filtered coffee, tea, and cola) and distilled water. From each group of denture teeth, 4 sets of maxillary anterior denture teeth were immersed in each of the 4 solutions. The color values of denture teeth were measured colorimetrically with the Gardner XL 20 Tristimulus Colorimeter (Gardner Lab. Inc., Bethesda, Maryland, USA). Color changes were characterized in the CIEL*a*b* color space. Color change values were determined after 1 day, 1 week, 2 weeks, and 4 weeks. The color difference values were calculated and then evaluated by two-way ANOVA statistically. The filtered coffee solution was found to be more chromogenic than the other 2 staining solutions, while porcelain denture teeth materials were more color stable. Assuming the color change of deltaE* < 1.0 as a discernible limit and deltaE* = 3.3 as an acceptable value, the filtered coffee, tea, and cola had slight staining effects on all 6 groups of denture teeth.

A Discrete Model for Color Naming

NASA Astrophysics Data System (ADS)

Menegaz, G.; Le Troter, A.; Sequeira, J.; Boi, J. M.

2006-12-01

The ability to associate labels to colors is very natural for human beings. Though, this apparently simple task hides very complex and still unsolved problems, spreading over many different disciplines ranging from neurophysiology to psychology and imaging. In this paper, we propose a discrete model for computational color categorization and naming. Starting from the 424 color specimens of the OSA-UCS set, we propose a fuzzy partitioning of the color space. Each of the 11 basic color categories identified by Berlin and Kay is modeled as a fuzzy set whose membership function is implicitly defined by fitting the model to the results of an ad hoc psychophysical experiment (Experiment 1). Each OSA-UCS sample is represented by a feature vector whose components are the memberships to the different categories. The discrete model consists of a three-dimensional Delaunay triangulation of the CIELAB color space which associates each OSA-UCS sample to a vertex of a 3D tetrahedron. Linear interpolation is used to estimate the membership values of any other point in the color space. Model validation is performed both directly, through the comparison of the predicted membership values to the subjective counterparts, as evaluated via another psychophysical test (Experiment 2), and indirectly, through the investigation of its exploitability for image segmentation. The model has proved to be successful in both cases, providing an estimation of the membership values in good agreement with the subjective measures as well as a semantically meaningful color-based segmentation map.

Brilliance, contrast, colorfulness, and the perceived volume of device color gamut

NASA Astrophysics Data System (ADS)

Heckaman, Rodney L.

With the advent of digital video and cinema media technologies, much more is possible in achieving brighter and more vibrant colors, colors that transcend our experience. The challenge is in the realization of these possibilities in an industry rooted in 1950s technology where color gamut is represented with little or no insight into the way an observer perceives color as a complex mixture of the observer's intentions, desires, and interests. By today's standards, five perceptual attributes---brightness, lightness, colorfulness, chroma, and hue---are believed to be required for a complete specification. As a compelling case for such a representation, a display system is demonstrated that is capable of displaying color beyond the realm of object color, perceptually even beyond the spectrum locus of pure color. All this begs the question: Just what is meant by perceptual gamut? To this end, the attributes of perceptual gamut are identified through psychometric testing and the color appearance models CIELAB and CIECAM02. Then, by way of demonstration, these attributes were manipulated to test their application in wide gamut displays. In concert with these perceptual attributes and their manipulation, Ralph M. Evans' concept of brilliance as an attribute of perception that extends beyond the realm of everyday experience, and the theoretical studies of brilliance by Y. Nayatani, a method was developed for producing brighter, more colorful colors and deeper, darker colors with the aim of preserving object color perception---flesh tones in particular. The method was successfully demonstrated and tested in real images using psychophysical methods in the very real, practical application of expanding the gamut of sRGB into an emulation of the wide gamut, xvYCC encoding.

Influence of in-office whitening gel pH on hydrogen peroxide diffusion through enamel and color changes in bovine teeth.

PubMed

Pignoly, Christian; Camps, Lila; Susini, Guy; About, Imad; Camps, Jean

2012-04-01

To assess the influence of in-office whitening gel pH on whitening efficiency. Hydrogen peroxide diffusion and color changes on bovine teeth were assessed. Three gels with close hydrogen peroxide concentrations but with various pH levels were tested: Zoom 2 (Discus Dental), Opalescence Endo and Opalescence Boost (Ultradent). The pH levels were respectively: 3.0, 5.0 and 7.0. Thirty enamel slices and tooth crowns were used for both studies (n = 10 per group per study). Hydrogen peroxide diffusion through the enamel slices and the tooth crowns was spectrophotometrically recorded every 10 minutes for 1 hour to calculate the diffusion coefficients. Color changes were spectrophotometrically recorded every 10 minutes for 1 hour and quantified in term of CIE-Lab. The hydrogen peroxide diffusion coefficient through enamel ranged from 5.12 +/- 0.82 x 10(-9) cm2 s(-1) for pH 3 to 5.19 +/- 0.92 x 10(-9) cm2 S(-1) for pH 7. Through tooth crowns it ranged from 4.80 +/- 1.75 x 10(-10) cm2 s(-1) for pH 5 to 4.85 +/- 1.82 x 10(-10) cm2 s(-1) for pH 3. After 1 hour, the deltaE varied from 5.6 +/- 4.0 for pH 7 to 7.0 +/- 5.0 for pH 3 on enamel slices and from 3.9 +/- 2.5 for pH 5 to 4.9 +/- 3.5 for pH 7 on tooth crowns. There was no statistically significant difference between groups for both parameters.

Evaluating the accuracy of tooth color measurement by combining the Munsell color system and dental colorimeter.

PubMed

Chang, Jiun-Yao; Chen, Wen-Cheng; Huang, Ta-Ko; Wang, Jen-Chyan; Fu, Po-Sung; Chen, Jeng-Huey; Hung, Chun-Cheng

2012-09-01

As we pay increasing attention to dental aesthetics, tooth color matching has become an important part of daily dental practice. This aim of this study was to develop a method to enhance the accuracy of a tooth color matching machine. The Munsell color tabs in the range of natural human teeth were measured using a tooth color measuring machine (ShadeEye NCC). The machine's accuracy was analyzed using an analysis of variance test and a Tukey post-hoc test. When matching the Munsell color tabs with the ShadeEye NCC colorimeter, settings of Chroma greater than 6 and Value less than 4 showed unacceptable clinical results. When the CIELAB mode was used, the a* value (which represents the red-green axis in the Commission Internationale de l'Eclairage color space) made no significant difference (p=0.84), the L* value (which represents the lightness) resulted in a negative correlation, and the b* value (which represents the yellow-blue axis) resulted in a positive correlation with ΔE. When the Munsell color tabs and the Vitapan were measured in the same mode and compared, the inaccuracies showed that the Vitapan was not a proper tool for evaluating the stability and accuracy of ShadeEye NCC. By knowing the limitations of the machine, we evaluated the data using the Munsell color tabs; shade beyond the acceptable range should be reevaluated using a visual shade matching method, or if measured by another machine, this shade range should be covered to obtain more accurate results. Copyright © 2012. Published by Elsevier B.V.

Investigations of suprathreshold color-difference tolerances with different visual scales and different perceptual correlates using CRT colors.

PubMed

Wang, Zhehong; Xu, Haisong

2008-12-01

In order to investigate the performance of suprathreshold color-difference tolerances with different visual scales and different perceptual correlates, a psychophysical experiment was carried out by the method of constant stimuli using CRT colors. Five hue circles at three lightness (L*=30, 50, and 70) and chroma (C*ab=10, 20, and 30) levels were selected to ensure that the color-difference tolerances did not exceed the color gamut of the CRT display. Twelve color centers distributed evenly every 30 degrees along each hue circle were assessed by a panel of eight observers, and the corresponding color-difference tolerances were obtained. The hue circle with L*=50 and C*ab=20 was assessed with three different visual scales (DeltaV=3.06, 5.92, and 8.87 CIELAB units), which ranged from small to large visual scales, while the remaining hue circles were observed only with the small visual scale. The lightness tolerances had no significant correlation with the hue angles, while chroma and hue tolerances showed considerable hue angle dependences. The color-difference tolerances were linearly proportional to the visual scales but with different slopes. The lightness tolerances with different lightness levels but the same chroma showed the crispening effect to some extent, while the chroma and hue tolerances decreased with the increment of the lightness. For the color-difference tolerances with different chroma levels but the same lightness, there was no correlation between the lightness tolerances and the chroma levels, while the chroma and hue tolerances were nearly linearly proportional to the chroma levels.

Color difference thresholds in dentistry.

PubMed

Paravina, Rade D; Ghinea, Razvan; Herrera, Luis J; Bona, Alvaro D; Igiel, Christopher; Linninger, Mercedes; Sakai, Maiko; Takahashi, Hidekazu; Tashkandi, Esam; Perez, Maria del Mar

2015-01-01

The aim of this prospective multicenter study was to determine 50:50% perceptibility threshold (PT) and 50:50% acceptability threshold (AT) of dental ceramic under simulated clinical settings. The spectral radiance of 63 monochromatic ceramic specimens was determined using a non-contact spectroradiometer. A total of 60 specimen pairs, divided into 3 sets of 20 specimen pairs (medium to light shades, medium to dark shades, and dark shades), were selected for psychophysical experiment. The coordinating center and seven research sites obtained the Institutional Review Board (IRB) approvals prior the beginning of the experiment. Each research site had 25 observers, divided into five groups of five observers: dentists-D, dental students-S, dental auxiliaries-A, dental technicians-T, and lay persons-L. There were 35 observers per group (five observers per group at each site ×7 sites), for a total of 175 observers. Visual color comparisons were performed using a viewing booth. Takagi-Sugeno-Kang (TSK) fuzzy approximation was used for fitting the data points. The 50:50% PT and 50:50% AT were determined in CIELAB and CIEDE2000. The t-test was used to evaluate the statistical significance in thresholds differences. The CIELAB 50:50% PT was ΔEab  = 1.2, whereas 50:50% AT was ΔEab  = 2.7. Corresponding CIEDE2000 (ΔE00 ) values were 0.8 and 1.8, respectively. 50:50% PT by the observer group revealed differences among groups D, A, T, and L as compared with 50:50% PT for all observers. The 50:50% AT for all observers was statistically different than 50:50% AT in groups T and L. A 50:50% perceptibility and ATs were significantly different. The same is true for differences between two color difference formulas ΔE00 /ΔEab . Observer groups and sites showed high level of statistical difference in all thresholds. Visual color difference thresholds can serve as a quality control tool to guide the selection of esthetic dental materials, evaluate clinical performance, and interpret visual and instrumental findings in clinical dentistry, dental research, and subsequent standardization. The importance of quality control in dentistry is reinforced by increased esthetic demands of patients and dental professionals. © 2015 Wiley Periodicals, Inc.

Design and optimization of color lookup tables on a simplex topology.

PubMed

Monga, Vishal; Bala, Raja; Mo, Xuan

2012-04-01

An important computational problem in color imaging is the design of color transforms that map color between devices or from a device-dependent space (e.g., RGB/CMYK) to a device-independent space (e.g., CIELAB) and vice versa. Real-time processing constraints entail that such nonlinear color transforms be implemented using multidimensional lookup tables (LUTs). Furthermore, relatively sparse LUTs (with efficient interpolation) are employed in practice because of storage and memory constraints. This paper presents a principled design methodology rooted in constrained convex optimization to design color LUTs on a simplex topology. The use of n simplexes, i.e., simplexes in n dimensions, as opposed to traditional lattices, recently has been of great interest in color LUT design for simplex topologies that allow both more analytically tractable formulations and greater efficiency in the LUT. In this framework of n-simplex interpolation, our central contribution is to develop an elegant iterative algorithm that jointly optimizes the placement of nodes of the color LUT and the output values at those nodes to minimize interpolation error in an expected sense. This is in contrast to existing work, which exclusively designs either node locations or the output values. We also develop new analytical results for the problem of node location optimization, which reduces to constrained optimization of a large but sparse interpolation matrix in our framework. We evaluate our n -simplex color LUTs against the state-of-the-art lattice (e.g., International Color Consortium profiles) and simplex-based techniques for approximating two representative multidimensional color transforms that characterize a CMYK xerographic printer and an RGB scanner, respectively. The results show that color LUTs designed on simplexes offer very significant benefits over traditional lattice-based alternatives in improving color transform accuracy even with a much smaller number of nodes.

Use of natural and modified cyclodextrins as inhibiting agents of peach juice enzymatic browning.

PubMed

López-Nicolas, José M; Pérez-López, Antonio J; Carbonell-Barrachina, Angel; García-Carmona, Francisco

2007-06-27

Although cyclodextrins (CDs) have been successfully used as antibrowning agents in different fruit juices, no research has studied the effect of these compounds on enzymatic browning in peach juice. In this paper, the color of fresh peach juice was evaluated in the presence of two types of natural (alpha-CD and beta-CD) and a modified (maltosyl-beta-CD) CD, and the effectiveness of these compounds as browning inhibitors was determined using the color space CIELAB system. Moreover, to clarify the mechanism by which CDs inhibit peach juice enzymatic browning, the process was kinetically modeled in the absence and presence of CDs using a colorimetric method; the apparent complexation constants between the mixtures of diphenols present in peach juice and some types of CD were calculated. The results show that the highest affinity constant was presented by alpha-CD (Kc = 18.31 mM-1) followed by maltosyl-beta-CD (Kc = 11.17 mM-1), whereas beta-CD was incapable of inhibiting peach juice enzymatic browning. Cyclodextrin; browning; peach; juice; color; polyphenol oxidase.

Influence of resin cement shade on the color and translucency of ceramic veneers

PubMed Central

HERNANDES, Daiana Kelly Lopes; ARRAIS, Cesar Augusto Galvão; de LIMA, Erick; CESAR, Paulo Francisco; RODRIGUES, José Augusto

2016-01-01

ABSTRACT Objective This in vitro study evaluated the effect of two different shades of resin cement (RC- A1 and A3) layer on color change, translucency parameter (TP), and chroma of low (LT) and high (HT) translucent reinforced lithium disilicate ceramic laminates. Material and Methods One dual-cured RC (Variolink II, A1- and A3-shade, Ivoclar Vivadent) was applied to 1-mm thick ceramic discs to create thin RC films (100 µm thick) under the ceramics. The RC was exposed to light from a LED curing unit. Color change (ΔE) of ceramic discs was measured according to CIEL*a*b* system with a standard illuminant D65 in reflectance mode in a spectrophotometer, operating in the light range of 360-740 nm, equipped with an integrating sphere. The color difference between black (B) and white (W) background readings was used for TP analysis, while chroma was calculated by the formula C* ab=(a*2+b*2)½. ΔE of 3.3 was set as the threshold of clinically unacceptable. The results were evaluated by two-way ANOVA followed by Tukey's post hoc test. Results HT ceramics showed higher ΔE and higher TP than LT ceramics. A3-shade RC promoted higher ΔE than A1-shade cement, regardless of the ceramic translucency. No significant difference in TP was noted between ceramic discs with A1- and those with A3-shade cement. Ceramic with underlying RC showed lower TP than discs without RC. HT ceramics showed lower chroma than LT ceramics, regardless of the resin cement shade. The presence of A3-shade RC resulted in higher chroma than the presence of A1-shade RC. Conclusions Darker underlying RC layer promoted more pronounced changes in ceramic translucency, chroma, and shade of high translucent ceramic veneers. These differences may not be clinically differentiable. PMID:27556211

Influence of resin cement shade on the color and translucency of ceramic veneers.

PubMed

Hernandes, Daiana Kelly Lopes; Arrais, Cesar Augusto Galvão; Lima, Erick de; Cesar, Paulo Francisco; Rodrigues, José Augusto

2016-01-01

This in vitro study evaluated the effect of two different shades of resin cement (RC- A1 and A3) layer on color change, translucency parameter (TP), and chroma of low (LT) and high (HT) translucent reinforced lithium disilicate ceramic laminates. One dual-cured RC (Variolink II, A1- and A3-shade, Ivoclar Vivadent) was applied to 1-mm thick ceramic discs to create thin RC films (100 µm thick) under the ceramics. The RC was exposed to light from a LED curing unit. Color change (ΔE) of ceramic discs was measured according to CIEL*a*b* system with a standard illuminant D65 in reflectance mode in a spectrophotometer, operating in the light range of 360-740 nm, equipped with an integrating sphere. The color difference between black (B) and white (W) background readings was used for TP analysis, while chroma was calculated by the formula C*ab=(a*2+b*2)½. ΔE of 3.3 was set as the threshold of clinically unacceptable. The results were evaluated by two-way ANOVA followed by Tukey's post hoc test. HT ceramics showed higher ΔE and higher TP than LT ceramics. A3-shade RC promoted higher ΔE than A1-shade cement, regardless of the ceramic translucency. No significant difference in TP was noted between ceramic discs with A1- and those with A3-shade cement. Ceramic with underlying RC showed lower TP than discs without RC. HT ceramics showed lower chroma than LT ceramics, regardless of the resin cement shade. The presence of A3-shade RC resulted in higher chroma than the presence of A1-shade RC. Darker underlying RC layer promoted more pronounced changes in ceramic translucency, chroma, and shade of high translucent ceramic veneers. These differences may not be clinically differentiable.

An Underwater Color Image Quality Evaluation Metric.

PubMed

Yang, Miao; Sowmya, Arcot

2015-12-01

Quality evaluation of underwater images is a key goal of underwater video image retrieval and intelligent processing. To date, no metric has been proposed for underwater color image quality evaluation (UCIQE). The special absorption and scattering characteristics of the water medium do not allow direct application of natural color image quality metrics especially to different underwater environments. In this paper, subjective testing for underwater image quality has been organized. The statistical distribution of the underwater image pixels in the CIELab color space related to subjective evaluation indicates the sharpness and colorful factors correlate well with subjective image quality perception. Based on these, a new UCIQE metric, which is a linear combination of chroma, saturation, and contrast, is proposed to quantify the non-uniform color cast, blurring, and low-contrast that characterize underwater engineering and monitoring images. Experiments are conducted to illustrate the performance of the proposed UCIQE metric and its capability to measure the underwater image enhancement results. They show that the proposed metric has comparable performance to the leading natural color image quality metrics and the underwater grayscale image quality metrics available in the literature, and can predict with higher accuracy the relative amount of degradation with similar image content in underwater environments. Importantly, UCIQE is a simple and fast solution for real-time underwater video processing. The effectiveness of the presented measure is also demonstrated by subjective evaluation. The results show better correlation between the UCIQE and the subjective mean opinion score.

Protection of polyphenols in blueberry juice by vacuum-assisted block freeze concentration.

PubMed

Orellana-Palma, Patricio; Petzold, Guillermo; Pierre, Lissage; Pensaben, José Manuel

2017-11-01

Block freeze concentration allows produces high-quality cryoconcentrates with important protection of valuable components from fresh fruit juices. The aim of this study was to investigate the use of vacuum-assisted block freeze concentration under different experimental conditions to protect polyphenols in the elaboration of concentrated blueberry juice. Fresh blueberry juice was radial or unidirectional frozen at -20 and -80 °C for 12 h and vacuum process was performed at 80 kPa during 120 min. Results showed a significant solute increased in the concentrated fraction in all treatments, and the best treatment was - 20 °C/unidirectional with a value of ≈63 °Brix, equivalent to an increase of 3.8 times in the total polyphenol content (76% of retention). The color of concentrated samples was darker than the initial sample, with ΔE* values of >25 CIELab units in all treatments. The vacuum-assisted block freeze concentrations was an effective technology for protecting polyphenols and obtain a concentrated with a higher concentration of solids from blueberry juice, as well as interesting values of process parameters. Copyright © 2017 Elsevier Ltd. All rights reserved.

Protection of color and chemical degradation of anthocyanin from purple corn (Zea mays L.) by zinc ions and alginate through chemical interaction in a beverage model.

PubMed

Luna-Vital, Diego; Cortez, Regina; Ongkowijoyo, Paulina; Gonzalez de Mejia, Elvira

2018-03-01

Anthocyanin-rich purple corn pericarp water extract (PCW) has the potential to be used as a natural pigment in beverages. However, it has a limited shelf-life in aqueous solutions. The aim was to evaluate the effect of zinc ion (Zn 2+ ) and alginate on color and chemical stability of anthocyanins from colored corn (PCW) in a beverage model for 12weeks. PCW was incorporated to Kool-Aid® Invisible™ along with ZnCl 2 and/or alginate. Individual ANC were quantified through HPLC, and color stability was evaluated through the CIE-L*a*b* color system. Complexation between PCW and Zn/alginate was evaluated with fluorescence spectroscopy. The combination of Zn and alginate was the most effective treatment improving the half-life of total ANC concentration (10.4weeks), cyanidin-3-O-glucoside (7.5weeks) and chroma (18.4weeks), compared to only PCW (6.6, 4.5 and 12.7weeks, respectively). Zn and alginate had bimolecular quenching constants (Zn k q : 3.4×10 11 M -1 S -1 and AA k q : 1.0×10 12 M -1 S -1 ) suggesting that fluorescence quenching was binding rather than collisional. Results suggested that Zn/alginate interacted with ANC from purple corn slowing its chemical degradation. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Quantitative Theory of Human Color Choices

PubMed Central

Komarova, Natalia L.; Jameson, Kimberly A.

2013-01-01

The system for colorimetry adopted by the Commission Internationale de l’Eclairage (CIE) in 1931, along with its subsequent improvements, represents a family of light mixture models that has served well for many decades for stimulus specification and reproduction when highly controlled color standards are important. Still, with regard to color appearance many perceptual and cognitive factors are known to contribute to color similarity, and, in general, to all cognitive judgments of color. Using experimentally obtained odd-one-out triad similarity judgments from 52 observers, we demonstrate that CIE-based models can explain a good portion (but not all) of the color similarity data. Color difference quantified by CIELAB ΔE explained behavior at levels of 81% (across all colors), 79% (across red colors), and 66% (across blue colors). We show that the unexplained variation cannot be ascribed to inter- or intra-individual variations among the observers, and points to the presence of additional factors shared by the majority of responders. Based on this, we create a quantitative model of a lexicographic semiorder type, which shows how different perceptual and cognitive influences can trade-off when making color similarity judgments. We show that by incorporating additional influences related to categorical and lightness and saturation factors, the model explains more of the triad similarity behavior, namely, 91% (all colors), 90% (reds), and 87% (blues). We conclude that distance in a CIE model is but the first of several layers in a hierarchy of higher-order cognitive influences that shape color triad choices. We further discuss additional mitigating influences outside the scope of CIE modeling, which can be incorporated in this framework, including well-known influences from language, stimulus set effects, and color preference bias. We also discuss universal and cultural aspects of the model as well as non-uniformity of the color space with respect to different cultural biases. PMID:23409103

Practical method for appearance match between soft copy and hard copy

NASA Astrophysics Data System (ADS)

Katoh, Naoya

1994-04-01

CRT monitors are often used as a soft proofing device for the hard copy image output. However, what the user sees on the monitor does not match its output, even if the monitor and the output device are calibrated with CIE/XYZ or CIE/Lab. This is especially obvious when correlated color temperature (CCT) of CRT monitor's white point significantly differs from ambient light. In a typical office environment, one uses a computer graphic monitor having a CCT of 9300K in a room of white fluorescent light of 4150K CCT. In such a case, human visual system is partially adapted to the CRT monitor's white point and partially to the ambient light. The visual experiments were performed on the effect of the ambient lighting. Practical method for soft copy color reproduction that matches the hard copy image in appearance is presented in this paper. This method is fundamentally based on a simple von Kries' adaptation model and takes into account the human visual system's partial adaptation and contrast matching.

An investigation of density measurement method for yarn-dyed woven fabrics based on dual-side fusion technique

NASA Astrophysics Data System (ADS)

Zhang, Rui; Xin, Binjie

2016-08-01

Yarn density is always considered as the fundamental structural parameter used for the quality evaluation of woven fabrics. The conventional yarn density measurement method is based on one-side analysis. In this paper, a novel density measurement method is developed for yarn-dyed woven fabrics based on a dual-side fusion technique. Firstly, a lab-used dual-side imaging system is established to acquire both face-side and back-side images of woven fabric and the affine transform is used for the alignment and fusion of the dual-side images. Then, the color images of the woven fabrics are transferred from the RGB to the CIE-Lab color space, and the intensity information of the image extracted from the L component is used for texture fusion and analysis. Subsequently, three image fusion methods are developed and utilized to merge the dual-side images: the weighted average method, wavelet transform method and Laplacian pyramid blending method. The fusion efficacy of each method is evaluated by three evaluation indicators and the best of them is selected to do the reconstruction of the complete fabric texture. Finally, the yarn density of the fused image is measured based on the fast Fourier transform, and the yarn alignment image could be reconstructed using the inverse fast Fourier transform. Our experimental results show that the accuracy of density measurement by using the proposed method is close to 99.44% compared with the traditional method and the robustness of this new proposed method is better than that of conventional analysis methods.

Wines in contact with oak wood: the impact of the variety (Carménère and Cabernet Sauvignon), format (barrels, chips and staves) and aging time on the phenolic composition.

PubMed

Laqui-Estaña, Jaime; López-Solís, Remigio; Peña-Neira, Álvaro; Medel-Marabolí, Marcela; Obreque-Slier, Elías

2018-06-13

This study characterized the flavonoid and non-flavonoid phenolic composition of Carménère and Cabernet Sauvignon wines that were in contact with barrels, chips and staves during a 12-month aging period. The wines were evaluated by spectrophotometric (for total phenols, anthocyanins and tannins, colorant intensity, hue, CIElab parameters and fractionation into mono-, oligo- and polymer of proanthocyanidins) and HPLC-DAD analyses (for ellagitannins, gallotannins, anthocyanins and low molecular weight phenols). Wines in contact with oak wood presented a strong enrichment with non-flavonoid compounds, such as caffeic, gallic, ellagic acids and ellagitannins. Wines in contact with staves stood out for the increased presence of total phenols, vanillic acid and higher color intensity, while wines aged in contact with chips showed large contents of proanthocyanidin gallates. Wines aged in barrels exhibited high contents of ellagitannins and ethyl gallates. The effect of wood on the phenolic composition was mostly associated to the original and intrinsic characteristics of each grape variety. Extraction of phenolic compounds from oak wood during wine aging is closely related to the wood format, grape variety (Carménère or Cabernet Sauvignon) and aging time. The final effect of wood on wine would be related not just to the transference of polyphenols from wood but also to structural modifications of grape polyphenols. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Masking properties of ceramics for veneer restorations.

PubMed

Skyllouriotis, Andreas L; Yamamoto, Hideo L; Nathanson, Dan

2017-10-01

The translucency and opacity of ceramics play a significant role in emulating the natural color of teeth, but studies of the masking properties and limitations of dental ceramics when used as monolayer restorations are lacking. The purpose of this in vitro study was to determine the translucency of 6 materials used for veneer restorations by assessing their translucency parameters (TPs), contrast ratios (CRs), and potential to mask dark tooth colors. Ten square- or disk-shaped specimens (0.5-mm thickness, shade A2) were fabricated from Vitablocks Mark II (VMII; Vita Zahnfabrik), IPS e.max CAD LT (EMXC LT; Ivoclar Vivadent AG), IPS e.max CAD HT (EMXC HT; Ivoclar Vivadent AG), IPS Empress CAD LT (EMP LT; Ivoclar Vivadent AG), IPS e.max Press LT (EMXP LT; Ivoclar Vivadent AG), and CZR (CZR; Kuraray Noritake Dental Inc). Their luminance (Y) values over black and over white tiles were measured, followed by their color (CIELab) over black tiles and white tiles and shaded A2 (control group), A3.5, A4, and B4 acrylic resin blocks. All measurements were performed using a spectrophotometer in 2 different areas on each specimen. Then CRs, TPs, and color differences (over shaded backgrounds) were determined. Data were subjected to 1-way and 2-way ANOVA (α=.05) for analysis. Mean CR values of EMXP LT were significantly higher than those of the other tested materials, whereas VMII and EMXC HT had the lowest values (P<.001). Mean TP values over black and over white backgrounds of VMII and EMXC HT were significantly higher than those of the other tested materials, while EMXP LT and EMXC LT revealed the lowest values (P<.001). Background shade A4 displayed the highest mean effect (expressed in ΔE* values) on the color of the ceramic materials, whereas shade B4 demonstrated the lowest mean background effect (P<.001). Significant differences in translucency among the tested ceramics were revealed (P<.001). The EMXC LT and EMXP LT groups were the least translucent under the conditions of this study (P<.001). All tested ceramics exhibited poor masking properties against the A4 background. The color differences of most tested ceramics were more acceptable when tested against the B4 background (ΔE*≤3.3). Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Effect of sealant agents on the color stability and surface roughness of nanohybrid composite resins.

PubMed

Dede, Doğu Ömür; Şahin, Onur; Koroglu, Aysegül; Yilmaz, Burak

2016-07-01

The effect of sealant agents on the surface roughness and color stability of nanohybrid composite resins is unknown. The purpose of this in vitro study was to evaluate the effect of sealant agents on the surface roughness and color stability of 4 nanohybrid composite resin materials. Forty disks (10×2 mm) were fabricated for each nanohybrid composite resin material (Z-550, Tetric EvoCeram, Clearfill Majesty, Ice) (N=160) and divided into 4 surface treatment groups: 1 conventional polishing (control) and 3 different sealant agent (Palaseal, Optiglaze, BisCover) coupling groups (n=10). The specimens were thermocycled, and surface roughness (Ra) values were obtained with a profilometer. Scanning electron microscope images were also recorded. CIELab color parameters of each specimen were measured with a spectrophotometer before and after 7 days of storage in a coffee solution. Color differences were calculated by the CIEDE 2000 (ΔE00) formula. The data were statistically analyzed by 2-way ANOVA and by the Tukey HSD test (α=.05). The surface treatment technique significantly affected the Ra values of the composite resins tested (P<.001). The interaction between the surface treatment technique and composite resin material was also significant for ΔE00 values (P<.05). Within the composite resin groups, significant decreases in Ra were observed only for the Palaseal agent coupled composite resin groups (except Ice) compared with the control groups (P<.05). Scanning electron microscope images revealed rougher surfaces with conventionally polished groups compared with test groups. Conventionally polished groups had the highest ΔE00 (3.09 to 3.49) values for each composite resin group, except for BisCover applied Clearfill Majesty (P<.05). Within the composite resin groups, significant differences were observed between the color change seen with BisCover and other sealants for Clearfill Majesty composite resin (P<.05). Using Palaseal agent on all tested composite resins except for Ice produced smoother surfaces. All surface sealant agents provided less discoloration of nanohybrid composite resins after coffee staining compared with conventional polishing except for BisCover applied Clearfill Majesty composite resin. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Preliminary evaluation of a fully automated quantitative framework for characterizing general breast tissue histology via color histogram and color texture analysis

NASA Astrophysics Data System (ADS)

Keller, Brad M.; Gastounioti, Aimilia; Batiste, Rebecca C.; Kontos, Despina; Feldman, Michael D.

2016-03-01

Visual characterization of histologic specimens is known to suffer from intra- and inter-observer variability. To help address this, we developed an automated framework for characterizing digitized histology specimens based on a novel application of color histogram and color texture analysis. We perform a preliminary evaluation of this framework using a set of 73 trichrome-stained, digitized slides of normal breast tissue which were visually assessed by an expert pathologist in terms of the percentage of collagenous stroma, stromal collagen density, duct-lobular unit density and the presence of elastosis. For each slide, our algorithm automatically segments the tissue region based on the lightness channel in CIELAB colorspace. Within each tissue region, a color histogram feature vector is extracted using a common color palette for trichrome images generated with a previously described method. Then, using a whole-slide, lattice-based methodology, color texture maps are generated using a set of color co-occurrence matrix statistics: contrast, correlation, energy and homogeneity. The extracted features sets are compared to the visually assessed tissue characteristics. Overall, the extracted texture features have high correlations to both the percentage of collagenous stroma (r=0.95, p<0.001) and duct-lobular unit density (r=0.71, p<0.001) seen in the tissue samples, and several individual features were associated with either collagen density and/or the presence of elastosis (p<=0.05). This suggests that the proposed framework has promise as a means to quantitatively extract descriptors reflecting tissue-level characteristics and thus could be useful in detecting and characterizing histological processes in digitized histology specimens.

Effects of chromatic image statistics on illumination induced color differences.

PubMed

Lucassen, Marcel P; Gevers, Theo; Gijsenij, Arjan; Dekker, Niels

2013-09-01

We measure the color fidelity of visual scenes that are rendered under different (simulated) illuminants and shown on a calibrated LCD display. Observers make triad illuminant comparisons involving the renderings from two chromatic test illuminants and one achromatic reference illuminant shown simultaneously. Four chromatic test illuminants are used: two along the daylight locus (yellow and blue), and two perpendicular to it (red and green). The observers select the rendering having the best color fidelity, thereby indirectly judging which of the two test illuminants induces the smallest color differences compared to the reference. Both multicolor test scenes and natural scenes are studied. The multicolor scenes are synthesized and represent ellipsoidal distributions in CIELAB chromaticity space having the same mean chromaticity but different chromatic orientations. We show that, for those distributions, color fidelity is best when the vector of the illuminant change (pointing from neutral to chromatic) is parallel to the major axis of the scene's chromatic distribution. For our selection of natural scenes, which generally have much broader chromatic distributions, we measure a higher color fidelity for the yellow and blue illuminants than for red and green. Scrambled versions of the natural images are also studied to exclude possible semantic effects. We quantitatively predict the average observer response (i.e., the illuminant probability) with four types of models, differing in the extent to which they incorporate information processing by the visual system. Results show different levels of performance for the models, and different levels for the multicolor scenes and the natural scenes. Overall, models based on the scene averaged color difference have the best performance. We discuss how color constancy algorithms may be improved by exploiting knowledge of the chromatic distribution of the visual scene.

Daily Consumption of a Fruit and Vegetable Smoothie Alters Facial Skin Color

PubMed Central

Tan, Kok Wei; Graf, Brigitte A.; Mitra, Soma R.; Stephen, Ian D.

2015-01-01

Consumption of dietary carotenoids or carotenoid supplements can alter the color (yellowness) of human skin through increased carotenoid deposition in the skin. As fruit and vegetables are the main dietary sources of carotenoids, skin yellowness may be a function of regular fruit and vegetable consumption. However, most previous studies have used tablets or capsules to supplement carotenoid intake, and less is known of the impact of increased fruit and vegetable consumption on skin color. Here, we examined skin color changes in an Asian population (Malaysian Chinese ethnicity) over a six week dietary intervention with a carotenoid-rich fruit smoothie. Eighty one university students (34 males, 47 females; mean age 20.48) were assigned randomly to consuming either a fruit smoothie (intervention group) or mineral water (control group) daily for six weeks. Participants’ skin yellowness (CIELab b*), redness (a*) and luminance (L*) were measured at baseline, twice during the intervention period and at a two-week follow-up, using a handheld reflectance spectrophotometer. Results showed a large increment in skin yellowness (p<0.001) and slight increment in skin redness (p<0.001) after 4 weeks of intervention for participants in the intervention group. Skin yellowness and skin redness remained elevated at the two week follow up measurement. In conclusion, intervention with a carotenoid-rich fruit smoothie is associated with increased skin redness and yellowness in an Asian population. Changes in the reflectance spectrum of the skin suggest that this color change was caused by carotenoid deposition in the skin. PMID:26186449

Daily Consumption of a Fruit and Vegetable Smoothie Alters Facial Skin Color.

PubMed

Tan, Kok Wei; Graf, Brigitte A; Mitra, Soma R; Stephen, Ian D

2015-01-01

Consumption of dietary carotenoids or carotenoid supplements can alter the color (yellowness) of human skin through increased carotenoid deposition in the skin. As fruit and vegetables are the main dietary sources of carotenoids, skin yellowness may be a function of regular fruit and vegetable consumption. However, most previous studies have used tablets or capsules to supplement carotenoid intake, and less is known of the impact of increased fruit and vegetable consumption on skin color. Here, we examined skin color changes in an Asian population (Malaysian Chinese ethnicity) over a six week dietary intervention with a carotenoid-rich fruit smoothie. Eighty one university students (34 males, 47 females; mean age 20.48) were assigned randomly to consuming either a fruit smoothie (intervention group) or mineral water (control group) daily for six weeks. Participants' skin yellowness (CIELab b*), redness (a*) and luminance (L*) were measured at baseline, twice during the intervention period and at a two-week follow-up, using a handheld reflectance spectrophotometer. Results showed a large increment in skin yellowness (p<0.001) and slight increment in skin redness (p<0.001) after 4 weeks of intervention for participants in the intervention group. Skin yellowness and skin redness remained elevated at the two week follow up measurement. In conclusion, intervention with a carotenoid-rich fruit smoothie is associated with increased skin redness and yellowness in an Asian population. Changes in the reflectance spectrum of the skin suggest that this color change was caused by carotenoid deposition in the skin.

Color universal design: analysis of color category dependency on color vision type (4)

NASA Astrophysics Data System (ADS)

Ikeda, Tomohiro; Ichihara, Yasuyo G.; Kojima, Natsuki; Tanaka, Hisaya; Ito, Kei

2013-02-01

This report is af ollow-up to SPIE-IS+T / Vol. 7528 7528051-8, SPIE-IS+T / Vol. 7866 78660J-1-8 and SPIE-IS+T / Vol. 8292 829206-1-8. Colors are used to communicate information in various situations, not just for design and apparel. However, visual information given only by color may be perceived differently by individuals with different color vision types. Human color vision is non-uniform and the variation in most cases is genetically linked to L-cones and M-cones. Therefore, color appearance is not the same for all color vision types. Color Universal Design is an easy-to-understand system that was created to convey color-coded information accurately to most people, taking color vision types into consideration. In the present research, we studied trichromat (C-type), prolan (P-type), and deutan (D-type) forms of color vision. We here report the result of two experiments. The first was the validation of the confusion colors using the color chart on CIELAB uniform color space. We made an experimental color chart (total of color cells is 622, the color difference between color cells is 2.5) for fhis experiment, and subjects have P-type or D-type color vision. From the data we were able to determine "the limits with high probability of confusion" and "the limits with possible confusion" around various basing points. The direction of the former matched with the theoretical confusion locus, but the range did not extend across the entire a* range. The latter formed a belt-like zone above and below the theoretical confusion locus. This way we re-analyzed a part of the theoretical confusion locus suggested by Pitt-Judd. The second was an experiment in color classification of the subjects with C-type, P-type, or D-type color vision. The color caps of fhe 100 Hue Test were classified into seven categories for each color vision type. The common and different points of color sensation were compared for each color vision type, and we were able to find a group of color caps fhat people with C-, P-, and D-types could all recognize as distinguishable color categories. The result could be used as the basis of a color scheme for future Color Universal Design.

Outdoor weathering of facial prosthetic elastomers differing in Durometer hardness.

PubMed

Willett, Emily S; Beatty, Mark W

2015-03-01

Facial prosthetic elastomers with wide ranges in hardness are available, yet material weatherability is unknown. The purpose of this study was to assess color, Durometer hardness, and tensile property changes after 3000 hours of outdoor weathering. Unpigmented elastomers with Durometer hardness 5, 30, 50, 70, and A-2186 were polymerized into dumbbells (ASTM D412) and disks, 34 mm in diameter by 6 mm thick. Materials were subjected to outdoor or time passage environments for 3000 hours. CIELab color (n=5), Durometer hardness (n=5), and tensile mechanical properties (n=10) were measured at 0 and 3000 hours, and group differences were assessed by material and weathering condition (ANOVA/Tukey, α=.05). Except for A-2186, the mean Durometer changes for all materials were 1 unit or less, with no significant differences observed between time passage and weathered groups (P≥.05). Three-thousand-hour tensile mechanical property results demonstrated nonsignificant differences between time passage and weathered materials but significantly changed properties from immediately tested materials (P<.001). Outdoor weathering induced perceptible but acceptable color changes (1.7≤ΔE*≤2.6) for elastomers with Durometer hardness 5 and 30 and A-2186. With a few exceptions, outdoor weathering produced relatively small changes in color, Durometer hardness, or tensile properties compared with time passage. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Colour Evaluation, Bioactive Compound Content, Phenolic Acid Profiles and in Vitro Biological Activity of Passerina del Frusinate White Wines: Influence of Pre-Fermentative Skin Contact Times.

PubMed

Carbone, Katya; Fiordiponti, Luciano

2016-07-22

Passerina del Frusinate is an autochthonous wine grape variety, which grows in the Lazio region that is currently being evaluated by local wine producers. In this study, colour properties (CIELab coordinates), bioactive compounds (total polyphenols and flavan-3-ols), HPLC-DAD phenolic acid profiles and in vitro biological activity of monovarietal Passerina del Frusinate white wines and the effect of different maceration times (0, 18 and 24 h) were evaluated based on these parameters. Results highlighted statistically significant differences for almost all analysed parameters due to a strong influence of the pre-fermentative skin contact time. The flavan content of macerated wines was six times higher than that of the control, while total polyphenols were 1.5 times higher. According to their phytochemical content, macerated wines showed the highest antiradical capacity tested by means of DPPH(•) and ABTS(+•) assays. Besides, prolonged maceration resulted in a reduction of CIELab coordinates as well as of the content of phenolic substances and antiradical capacity. Among the phenolic acids analysed, the most abundant were vanillic acid and caffeic acid; the latter proved to be the most susceptible to degradation as a result of prolonged maceration. Passerina del Frusinate appears as a phenol-rich white wine with a strong antioxidant potential similar to that of red wines.

Influence of composite type and light irradiance on color stability after immersion in different beverages.

PubMed

Alberton Da Silva, Victória; Alberton Da Silva, Simone; Pecho, Oscar E; Bacchi, Atais

2018-06-19

The aim of this study was to evaluate the color stability of two resin-based composites photo-activated by two light curing units (LCU) with different irradiances. Hundred disc-shaped specimens (2-mm thick) of a nanofilled (FZ- Filtek TM Z350 XT, 3M ESPE) and a microhybrid (ED-Empress ® Direct, Ivoclar Vivadent) composites were photo-activated with two LCU: Valo ® Cordless, Ultradent (VA-1800 mW/cm 2 ) or Radii-cal, SDI (RA-900 mW/cm 2 ). Samples (n = 5) were immersed during 12 days in distilled water (WT), orange juice (OJ), red wine (RW), coffee (CF), or Brazilian tea (BT). CIELAB coordinates were obtained using a spectrophotometer (Easyshade 4.0, Vita Zahnfabrik) before (T 0 ) and after (T 1 ) immersion. CIEDE2000 color difference (ΔE 00 ) and whiteness index for dentistry (WI D ) were calculated. Data was analyzed by two-way ANOVA and Tukey's test (α = 0.05%). FZ light-activated by VA showed higher L* and WI D values (T 0 ) and lower ΔE 00 values after immersion in WT, OJ, and RW. However, there was no effect of both factors on ΔE 00 when samples were immersed in BT and CF. ED light-activated by RA showed significant higher C* values (p ≤ .05). The nanofilled composite photo-activated with higher irradiance showed greater L* and WI D values and better color stability. However, all samples immersed in colored beverages showed ΔE 00 values above the acceptability threshold. Initial color of resin-based composites can change after immersion in staining beverages. However, the best color stability was obtained by the nanocomposite photo-activated by a light-curing unit of higher irradiance. © 2018 Wiley Periodicals, Inc.

Physico-chemical, colorimetric, rheological parameters and chemometric discrimination of the origin of Mugil cephalus' roes during the manufacturing process of Bottarga.

PubMed

Caredda, Marco; Addis, Margherita; Pes, Massimo; Fois, Nicola; Sanna, Gabriele; Piredda, Giovanni; Sanna, Gavino

2018-06-01

The aim of this work was to measure the physico-chemical and the colorimetric parameters of ovaries from Mugil cephalus caught in the Tortolì lagoon (South-East coast of Sardinia) along the steps of the manufacturing process of Bottarga, together with the rheological parameters of the final product. A lowering of all CIELab coordinates (lightness, redness and yellowness) was observed during the manufacture process. All CIELab parameters were used to build a Linear Discriminant Analysis (LDA) predictive model able to determine in real time if the roes had been subdued to a freezing process, with a success in prediction of 100%. This model could be used to identify the origin of the roes, since only the imported ones are frozen. The major changes of all the studied parameters (p < 0.05) were noted in the drying step rather than in the salting step. After processing, Bottarga was characterized by a pH value of 5.46 (CV = 2.8) and a moisture content of 25% (CV = 8), whereas the typical per cent amounts of proteins, fat and NaCl, calculated as a percentage on the dried weight, were 56 (CV = 2), 34 (CV = 3) and 3.6 (CV = 17), respectively. The physical chemical changes of the roes during the manufacturing process were consistent for moisture, which decreased by 28%, whereas the protein and the fat contents on the dried weight got respectively lower of 3% and 2%. NaCl content increased by 3.1%. Principal Component Analyses (PCA) were also performed on all data to establish trends and relationships among all parameters. Hardness and consistency of Bottarga were negatively correlated with the moisture content (r = -0.87 and r = -0.88, respectively), while its adhesiveness was negatively correlated with the fat content (r = -0.68). Copyright © 2018. Published by Elsevier Ltd.

Effective of diode laser on teeth enamel in the teeth whitening treatment

NASA Astrophysics Data System (ADS)

Klunboot, U.; Arayathanitkul, K.; Chitaree, R.; Emarat, N.

2011-12-01

This research purpose is to investigate the changing of teeth color and to study the surface of teeth after treatment by laser diode at different power densities for tooth whitening treatment. In the experiment, human-extracted teeth samples were divided into 7 groups of 6 teeth each. After that laser diode was irradiated to teeth, which were coated by 38% concentration of hydrogen peroxide, during for 20, 30 and 60 seconds at power densities of 10.9 and 52.1 W/cm2. The results of teeth color change were described by the CIEL*a*b* systems and the damage of teeth surface were investigated by scanning electron microscopy (SEM). The results showed that the power density of the laser diode could affect the whiteness of teeth. The high power density caused more luminous teeth than the low power density did, but on the other hand the high power density also caused damage to the teeth surface. Therefore, the laser diode at the low power densities has high efficiency for tooth whitening treatment and it has a potential for other clinical applications.

Application of Differential Colorimetry To Evaluate Anthocyanin-Flavonol-Flavanol Ternary Copigmentation Interactions in Model Solutions.

PubMed

Gordillo, Belén; Rodríguez-Pulido, Francisco J; González-Miret, M Lourdes; Quijada-Morín, Natalia; Rivas-Gonzalo, Julián C; García-Estévez, Ignacio; Heredia, Francisco J; Escribano-Bailón, M Teresa

2015-09-09

The combined effect of anthocyanin-flavanol-flavonol ternary interactions on the colorimetric and chemical stability of malvidin-3-glucoside has been studied. Model solutions with fixed malvidin-3-glucoside/(+)-catechin ratio (MC) and variable quercetin-3-β-d-glucoside concentration (MC+Q) and solutions with fixed malvidin-3-glucoside/quercetin-3-β-d-glucoside ratio (MQ) and variable (+)-catechin concentration (MQ+C) were tested at levels closer to those existing in wines. Color variations during storage were evaluated by differential colorimetry. Changes in the anthocyanin concentration were monitored by HPLC-DAD. CIELAB color-difference formulas were demonstrated to be of practical interest to assess the stronger and more stable interaction of quercetin-3-β-d-glucoside with MC binary mixture than (+)-catechin with MQ mixture. The results imply that MC+Q ternary solutions kept their intensity and bluish tonalities for a longer time in comparison to MQ+C solutions. The stability of malvidin-3-glucoside improves when the concentration of quercetin-3-β-d-glucoside increases in MC+Q mixtures, whereas the addition of (+)-catechin in MQ+C mixtures resulted in an opposite effect.

Perceptual color difference metric including a CSF based on the perception threshold

NASA Astrophysics Data System (ADS)

Rosselli, Vincent; Larabi, Mohamed-Chaker; Fernandez-Maloigne, Christine

2008-01-01

The study of the Human Visual System (HVS) is very interesting to quantify the quality of a picture, to predict which information will be perceived on it, to apply adapted tools ... The Contrast Sensitivity Function (CSF) is one of the major ways to integrate the HVS properties into an imaging system. It characterizes the sensitivity of the visual system to spatial and temporal frequencies and predicts the behavior for the three channels. Common constructions of the CSF have been performed by estimating the detection threshold beyond which it is possible to perceive a stimulus. In this work, we developed a novel approach for spatio-chromatic construction based on matching experiments to estimate the perception threshold. It consists in matching the contrast of a test stimulus with that of a reference one. The obtained results are quite different in comparison with the standard approaches as the chromatic CSFs have band-pass behavior and not low pass. The obtained model has been integrated in a perceptual color difference metric inspired by the s-CIELAB. The metric is then evaluated with both objective and subjective procedures.

Efficacy of different whitening modalities on bovine enamel and dentin.

PubMed

Wiegand, Annette; Vollmer, Doreen; Foitzik, Magdalena; Attin, Rengin; Attin, Thomas

2005-06-01

Previous studies have shown that bleaching treatment may be efficient in both enamel and dentin, but it is still unknown how much the subsurface dentin contributes to the color change of teeth. This in vitro study evaluated the whitening effect of different external bleaching agents on enamel-dentin slabs and subsurface dentin. Ninety bovine teeth were distributed among six groups (A, Opalescence 10%; B, Opalescence PF 15%; C, Opalescence Quick; D, Opalescence Extra Boost; E, Rapid White; F, Whitestrips). Two enamel-dentin specimens were prepared from the labial surface of each teeth. In one of the specimens enamel was removed, resulting in a dentin (CD) disc of 1 mm high. The labial and the pulpal sides of the second specimen were ground until the remaining enamel and dentin layers of the enamel-dentin sample (ED) were 1 mm each. Whitening treatment of the ED specimens was performed according to manufacturers' instructions. Pre- and posttreatment Lab values of ED samples were analyzed using CIE-Lab. Baseline Lab values of dentin were analyzed by evaluation of the CD specimen. Finally, enamel of the ED specimens was removed and color change of the exposed dentin (D) was recorded. For all treatment agents significant color changes (DeltaE) were observed for enamel-dentin samples and subsurface dentin specimens compared to controls. In groups A-D DeltaE was significantly higher in dentin than enamel-dentin. Furthermore, L and b values of bleached enamel-dentin and subsurface dentin samples differed significantly from baseline. Treatment with the tested external whitening bleaching agents resulted in color change of both enamel-dentin and subsurface dentin samples. The results indicate that color change of treated teeth might be highly influenced by color change of the subsurface dentin.

Origin of the color of Cv. rhapsody in blue rose and some other so-called "blue" roses.

PubMed

Gonnet, Jean-François

2003-08-13

Flowers of the rose cultivar Rhapsody in Blue display unusual colors, changing as they age, from a vivid red-purple to a lighter and duller purple, which are based on tonalities corresponding to hue angles between 340 and 320 degrees in the CIELAB scale. Unexpectedly, the chemical basis of these colors is among the simplest, featuring cyanin (cyanidin 3,5-di-O-glucoside), the most frequent anthocyanin in flowers, as the sole pigment and quercetin kaempferol glycosides as copigments at a relatively low copigment/pigment ratio (about 3/1), which usually produces magenta or red shades in roses. This color shift to bluer shades is coupled with the progressive accumulation of cyanin into vacuolar anthocyanic inclusions (AVIs), the occurrence of which increases as the petals grow older. In addition to the normal lambda(max) of cyanin at approximately 545 nm, the transmission spectra of live petals and of epidermal cells exhibit a second lambda(max) in the 620-625 nm range, the relative importance increasing with the presence of AVIs. In petals of fully opened flowers, the only pigmented structures in the vacuoles of epidermal cells are AVIs; their intense and massive absorption in the 520-640 nm area produces a much darker and bluer color than measured for the vacuolar solution present at the very first opening stage. Cyanin is probably "trapped" into AVIs at higher concentrations than would be possible in a vacuolar solution and in quinonoidal form, appearing purple-blue because of additional absorption in the 580-630 nm area. Quite similar pigmentation features were found in very ancient rose cultivars (cv. L'Evêque or Bleu Magenta), also displaying this type of so-called "blue" color.

Cell type classifiers for breast cancer microscopic images based on fractal dimension texture analysis of image color layers.

PubMed

Jitaree, Sirinapa; Phinyomark, Angkoon; Boonyaphiphat, Pleumjit; Phukpattaranont, Pornchai

2015-01-01

Having a classifier of cell types in a breast cancer microscopic image (BCMI), obtained with immunohistochemical staining, is required as part of a computer-aided system that counts the cancer cells in such BCMI. Such quantitation by cell counting is very useful in supporting decisions and planning of the medical treatment of breast cancer. This study proposes and evaluates features based on texture analysis by fractal dimension (FD), for the classification of histological structures in a BCMI into either cancer cells or non-cancer cells. The cancer cells include positive cells (PC) and negative cells (NC), while the normal cells comprise stromal cells (SC) and lymphocyte cells (LC). The FD feature values were calculated with the box-counting method from binarized images, obtained by automatic thresholding with Otsu's method of the grayscale images for various color channels. A total of 12 color channels from four color spaces (RGB, CIE-L*a*b*, HSV, and YCbCr) were investigated, and the FD feature values from them were used with decision tree classifiers. The BCMI data consisted of 1,400, 1,200, and 800 images with pixel resolutions 128 × 128, 192 × 192, and 256 × 256, respectively. The best cross-validated classification accuracy was 93.87%, for distinguishing between cancer and non-cancer cells, obtained using the Cr color channel with window size 256. The results indicate that the proposed algorithm, based on fractal dimension features extracted from a color channel, performs well in the automatic classification of the histology in a BCMI. This might support accurate automatic cell counting in a computer-assisted system for breast cancer diagnosis. © Wiley Periodicals, Inc.

Influence of Hemostatic Solution on Bond Strength and Physicochemical Properties of Resin Cement.

PubMed

Araújo, Isabela Sousa de; Prado, Célio Jesus do; Raposo, Luís Henrique Araújo; Soares, Carlos José; Zanatta, Rayssa Ferreira; Torres, Carlos Rocha Gomes; Ruggiero, Reinaldo; Silva, Gisele Rodrigues da

2017-01-01

The aim of this study was to evaluate the degree of conversion, color stability, chemical composition, and bond strength of a light-cured resin cement contaminated with three different hemostatic solutions. Specimens were prepared for the control (uncontaminated resin cement) and experimental groups (resin cement contaminated with one of the hemostatic solutions) according to the tests. For degree of conversion, DC (n = 5) and color analyses (n = 10), specimens (3 mm in diameter and 2 mm thick) were evaluated by Fourier transform infrared spectroscopy (FTIR) and CIELAB spectrophotometry (L*, a*, b*), respectively. For elemental chemical analysis (n = 1), specimens (2 mm thick and 6 mm in diameter) were evaluated by x-ray energy-dispersive spectroscopy (EDS). The bond strengths of the groups were assessed by the microshear test (n = 20) in a leucite-reinforced glass ceramic substrate, followed by failure mode analysis by scanning electron microscopy (SEM). The mean values, except for the elemental chemical evaluation and failure mode, were evaluated by ANOVA and Tukey's HSD test. The color stability was influenced by storage time (p<0.001) and interaction between contamination and storage time (p<0.001). Hemostop and Viscostat Clear contamination did not affect the DC, however Viscostat increased the DC. Bond strength of the resin cement to ceramic was negatively affected by the contaminants (p<0.001). Contamination by hemostatic agents affected the bond strength, degree of conversion, and color stability of the light-cured resin cement tested.

Effect of opacifiers and UV absorbers on pigmented maxillofacial silicone elastomer, part 1: color stability after artificial aging.

PubMed

Han, Ying; Powers, John M; Kiat-Amnuay, Sudarat

2013-06-01

Much dissatisfaction with the color instability and reduced lifetime of extraoral maxillofacial prostheses due to degradation has been reported. The purpose of this study was to compare the effect of a UV mineral-based light protecting agent (LP) on the color stability of pigmented maxillofacial silicone elastomer MDX-4210/Type A after artificial aging to 2 widely used opacifiers. Forty-five groups were established (n=225 total). Three different types of opacifiers (LP, titanium white dry pigment [TW], or silicone intrinsic white [SW]) were added to silicone MDX-4210/type A at 3 concentrations (5%, 10%, or 15%) and subsequently combined with each of 5 colors (no pigments [control], red, blue, yellow, or mixed pigments). Artists' oil pigment was used with LP and TW, while intrinsic silicone pigment was used to color SW. Before and after an energy exposure of 450 kJ/m(2), CIE L*a*b* values were measured with a spectrophotometer. The CIELAB 50:50% perceptibility (ΔE*=1.1) and acceptability threshold (ΔE*=3.0) were used to interpret color changes (ΔE*). Color differences after aging were subjected to 3-way ANOVA. Means were compared by the Fisher PLSD intervals at α=.05. The ΔE* values of all groups were below the acceptability threshold of ΔE*=3.0, except for the control group of SW at 10%, which showed the greatest color change (ΔE*=3.1). When mixed pigment groups were considered, at 5% concentration, LP showed the smallest color change, followed by SW and TW (P<.05); at 10%, no significant differences among the 3 opacifiers were noted (P>.05); at 15%, LP showed the smallest color change, followed by TW and SW (P<.05). All 3 opacifiers at all concentrations protected pigmented silicone MDX4-4210/Type A from color degradation. The LP group showed the smallest color changes. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Influence of implant abutment material on the color of different ceramic crown systems.

PubMed

Dede, Doğu Ömür; Armağanci, Arzu; Ceylan, Gözlem; Celik, Ersan; Cankaya, Soner; Yilmaz, Burak

2016-11-01

Ceramics are widely used for anterior restorations; however, clinical color reproduction still constitutes a challenge particularly when the ceramic crowns are used on titanium implant abutments. The purpose of this in vitro study was to investigate the effect of implant abutment material on the color of different ceramic material systems. Forty disks (11×1.5 mm, shade A2) were fabricated from medium-opacity (mo) and high-translucency (ht) lithium disilicate (IPS e.max) blocks, an aluminous ceramic (VITA In-Ceram Alumina), and a zirconia (Zirkonzahn) ceramic system. Disks were fabricated to represent 3 different implant abutments (zirconia, gold-palladium, and titanium) and dentin (composite resin, A2 shade) as background (11×2 mm). Disk-shaped composite resin specimens in A2 shade were fabricated to represent the cement layer. The color measurements of ceramic specimens were made on composite resin abutment materials using a spectrophotometer. CIELab color coordinates were recorded, and the color coordinates measured on composite resin background served as the control group. Color differences (ΔE 00 ) between the control and test groups were calculated. The data were analyzed with 2-way analysis of variance (ANOVA) and compared with the Tukey HSD test (α=.05). The ceramics system, abutment material, and their interaction were significant for ΔE 00 values (P<.001). Clinically unacceptable results (ΔE 00 >2.25) were observed for lithium disilicate ceramics on titanium abutments (2.46-2.50). The ΔE 00 values of lithium disilicate ceramics for gold-palladium and titanium abutments were significantly higher than for other groups (P<.05). The color results (ΔE 00 >2.25) of an implant-supported lithium disilicate ceramic restoration may be clinically unacceptable if it is fabricated over a titanium abutment. Zirconia may be a more suitable abutment material for implant-supported ceramic restorations. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Resin cement color stability and its influence on the final shade of all-ceramics.

PubMed

Kilinc, Evren; Antonson, Sibel A; Hardigan, Patrick C; Kesercioglu, Atilla

2011-07-01

Adhesive resin cements may go through internal discoloration, which may show-through and affect the appearance of translucent all-ceramic restorations. This in vitro study evaluated the amount of resin cement color change and its effect on the final shade of the all-ceramics. Three different resin cements in both light and dual-cure forms were included in the study (Nexus-2/Kerr; Appeal/Ivoclar Vivadent; Calibra/Dentsply). All resin cements contained veneered (IPS Empress Esthetic, ETC1 shade, 20 mm × 1 mm ingot discs) and uncovered groups (n=10/group), all luted on white backgrounds (acetalpolyoxymethylene/Delrin(®)). Curing was performed according to ISO standards with a calibrated LED curing-light (Flashlite 1401). Samples were stored in 37°C distilled water at dark. Spectrophotometric baseline color measurements (Color Eye 7000A) were performed from the samples' top surfaces at 24h (D65 illuminator). Samples were subjected to 65 h of accelerated ageing (Atlas Ci4000). Further color measurements from the same areas were recorded in CIEL*a*b* coordinates where a ΔE data above 3 was accepted as visible discoloration (OptiviewLite-1.9software). Statistical analysis was performed using a nested random effects model and Tukey's post hoc analysis. Light-cure groups showed better color stability in all three resins but only in Appeal resin cement, the dual-cure group discolored significantly more (p<0.001). More discoloration was recorded on uncovered cement groups that represented the exposed cement at the margins. There was no visible color change (ΔE>3) through the ceramic surface on any veneered group. All resin cements showed varying degrees of discoloration after accelerated ageing however their actual color change was partially masked by the ceramic. Dual-cure resin cements may affect aesthetics on restoration margins if directly exposed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Magnetic Measurements as a Useful Tool for the Evaluation of Spatial Variability of the Arable Horizon Thickness

NASA Astrophysics Data System (ADS)

Fattakhova, Leysan; Shinkarev, Alexandr; Ryzhikh, Lyudmila; Kosareva, Lina

2017-04-01

In normal practice, the thickness of the arable horizon is determined on the basis of field morphological descriptions, allowing the subjectivity of perception and judgment at the crucial role of experience of the researcher. The subject of special interest are independent analytical and technically relatively simple in design approaches to the diagnosis of the lower boundary of the blended plowing the profiles part. Theoretical premises to use spectrophotometry and magnetometry to arable horizon depth diagnose is based on the concept of regular color and magnetic properties vertical differentiation in a profile of virgin soils. This work is devoted to the comparative assessment of the possibility to objectively and reliably diagnose the lower boundary of the arable horizon in gray forest soils by determining the color characteristics and the magnetic susceptibility of their layer-wise samples. It was shown with arable gray forest soil (Cutanic Luvisols (Anthric)) as example that the magnetic susceptibility profile distribution curves can provide more reliable and objective assessment of the arable horizon thickness spatial variability than the profile curves of the color characteristics in the CIELAB coordinates. Therefore, magnetic measurements can be a useful tool for the tillage erosion estimation in the monitoring of soil characteristics in connection with the development of precision agriculture technologies and the organizing of agricultural field plot experiments.

Effect of resin shades on opacity of ceramic veneers and polymerization efficiency through ceramics.

PubMed

Öztürk, Elif; Chiang, Yu-Chih; Coşgun, Erdal; Bolay, Şükran; Hickel, Reinhard; Ilie, Nicoleta

2013-11-01

The aim of this study was to assess the effect of different resin cement shades on the opacity and color difference of ceramics and to determine the polymerization efficiency of the resin cement at different shades after curing through ceramics. Two different ceramics (IPS e.max Press and IPS Empress(®)CAD, Ivoclar Vivadent) were used for this study. A light-cured veneer luting resin (Variolink Veneer, Ivoclar Vivadent) in four different shades of HV+1, HV+3, LV-1, and LV-3 was used for the colorimetric measurements. The color and spectral reflectance of the ceramics were measured according to the CIELab color scale relative to the standard illuminant D65 on a reflection spectrophotometer (ColorEye7000A, USA). Color differences (ΔE values) and the contrast ratios (CR) of the different groups of samples were calculated. In order to analyse the polymerization efficiency of the resin cements, the micromechanical properties of the resins were measured with an automatic microhardness indenter (Fisherscope H100C, Germany). The results were analysed using one-way ANOVA and Tukey's HSD post hoc tests (SPSS 18.0). The one-way ANOVA test showed that the values of ΔE and CR of the different specimen groups were significantly different (p<0.05). Group 1 (20.7 ± 0.5) (IPS-CAD without resin cement) exhibited the highest and group 10 (14.8 ± 0.5) (e.max:HV+3) exhibited the lowest ΔE value. Significant differences in the micromechanical properties were identified among the tested resin cements in different shades (p<0.05). Resin cement shade is an important factor for the opacity of a restoration. Furthermore, the resin shade affects the micromechanical properties of the underlying resin cement. Copyright © 2013 Elsevier Ltd. All rights reserved.

A novel technique for the production of cool colored concrete tile and asphalt shingle roofing products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levinson, Ronnen; Akbari, Hashem; Berdahl, Paul

The widespread use of solar-reflective roofing materials can save energy, mitigate urban heat islands and slow global warming by cooling the roughly 20% of the urban surface that is roofed. In this study we created prototype solar-reflective nonwhite concrete tile and asphalt shingle roofing materials using a two-layer spray coating process intended to maximize both solar reflectance and factory-line throughput. Each layer is a thin, quick-drying, pigmented latex paint based on either acrylic or a poly(vinylidene fluoride)/acrylic blend. The first layer is a titanium dioxide rutile white basecoat that increases the solar reflectance of a gray-cement concrete tile from 0.18more » to 0.79, and that of a shingle surfaced with bare granules from 0.06 to 0.62. The second layer is a 'cool' color topcoat with weak near-infrared (NIR) absorption and/or strong NIR backscattering. Each layer dries within seconds, potentially allowing a factory line to pass first under the white spray, then under the color spray. We combined a white basecoat with monocolor topcoats in various shades of red, brown, green and blue to prepare 24 cool color prototype tiles and 24 cool color prototypes shingles. The solar reflectances of the tiles ranged from 0.26 (dark brown; CIELAB lightness value L* = 29) to 0.57 (light green; L* = 76); those of the shingles ranged from 0.18 (dark brown; L* = 26) to 0.34 (light green; L* = 68). Over half of the tiles had a solar reflectance of at least 0.40, and over half of the shingles had a solar reflectance of at least 0.25.« less

Orthogonal Relations and Color Constancy in Dichromatic Colorblindness

PubMed Central

Pridmore, Ralph W.

2014-01-01

This paper employs uniform color space to analyze relations in dichromacy (protanopia, deuteranopia, tritanopia). Fifty percent or less of dichromats represent the classical reduction form of trichromacy, where one of three cones is inoperative but normal trichromatic color mixture such as complementary colors (pairs that mix white) are accepted by the dichromat, whose data can thus be plotted to CIE chromaticity spaces. The remaining dichromats comprise many and varied more-complex gene arrays from mutations, recombinations, etc. Though perhaps a minority, the three reductionist types provide a simple standard, in genotype and phenotype, to which the more complex remainder may be compared. Here, previously published data on dichromacy are plotted and analyzed in CIELUV uniform color space to find spatial relations in terms of color appearance space (e.g., hue angle). Traditional residual (seen) hues for protanopia and deuteranopia (both red–green colorblindness) are yellow and blue, but analysis indicates the protanopic residual hues are more greenish yellow and reddish blue than in tradition. Results for three illuminants (D65, D50, B) imply four principles in the spatial structure of dichromacy: (1) complementarity of confusion hue pairs and of residual hue pairs; (2) orthogonality of confusion locus and residual hues locus at their intersection with the white point, in each dichromatic type; (3) orthogonality of protanopic and tritanopic confusion loci; and (4) inverse relations between protanopic and tritanopic systems generally, such that one's confusion hues are the other's residual hues. Two of the three dichromatic systems do not represent components of normal trichromatic vision as sometimes thought but are quite different. Wavelength shifts between illuminants demonstrate chromatic adaptation correlates exactly with that in trichromatic vision. In theory these results clarify relations in and between types of dichromacy. They also apply in Munsell and CIELAB color spaces but inexactly to the degree they employ inexact complementarity. PMID:25211128

Orthogonal relations and color constancy in dichromatic colorblindness.

PubMed

Pridmore, Ralph W

2014-01-01

This paper employs uniform color space to analyze relations in dichromacy (protanopia, deuteranopia, tritanopia). Fifty percent or less of dichromats represent the classical reduction form of trichromacy, where one of three cones is inoperative but normal trichromatic color mixture such as complementary colors (pairs that mix white) are accepted by the dichromat, whose data can thus be plotted to CIE chromaticity spaces. The remaining dichromats comprise many and varied more-complex gene arrays from mutations, recombinations, etc. Though perhaps a minority, the three reductionist types provide a simple standard, in genotype and phenotype, to which the more complex remainder may be compared. Here, previously published data on dichromacy are plotted and analyzed in CIELUV uniform color space to find spatial relations in terms of color appearance space (e.g., hue angle). Traditional residual (seen) hues for protanopia and deuteranopia (both red-green colorblindness) are yellow and blue, but analysis indicates the protanopic residual hues are more greenish yellow and reddish blue than in tradition. Results for three illuminants (D65, D50, B) imply four principles in the spatial structure of dichromacy: (1) complementarity of confusion hue pairs and of residual hue pairs; (2) orthogonality of confusion locus and residual hues locus at their intersection with the white point, in each dichromatic type; (3) orthogonality of protanopic and tritanopic confusion loci; and (4) inverse relations between protanopic and tritanopic systems generally, such that one's confusion hues are the other's residual hues. Two of the three dichromatic systems do not represent components of normal trichromatic vision as sometimes thought but are quite different. Wavelength shifts between illuminants demonstrate chromatic adaptation correlates exactly with that in trichromatic vision. In theory these results clarify relations in and between types of dichromacy. They also apply in Munsell and CIELAB color spaces but inexactly to the degree they employ inexact complementarity.

Effect of Energy Drinks on Discoloration of Silorane and Dimethacrylate-Based Composite Resins.

PubMed

Ahmadizenouz, Ghazaleh; Esmaeili, Behnaz; Ahangari, Zohreh; Khafri, Soraya; Rahmani, Aghil

2016-08-01

This study aimed to assess the effects of two energy drinks on color change (ΔE) of two methacrylate-based and a silorane-based composite resin after one week and one month. Thirty cubic samples were fabricated from Filtek P90, Filtek Z250 and Filtek Z350XT composite resins. All the specimens were stored in distilled water at 37°C for 24 hours. Baseline color values (L*a*b*) of each specimen were measured using a spectrophotometer according to the CIEL*a*b* color system. Ten randomly selected specimens from each composite were then immersed in the two energy drinks (Hype, Red Bull) and artificial saliva (control) for one week and one month. Color was re-assessed after each storage period and ΔE values were calculated. The data were analyzed using the Kruskal Wallis and Mann-Whitney U tests. Filtek Z250 composite showed the highest ΔE irrespective of the solutions at both time points. After seven days and one month, the lowest ΔE values were observed in Filtek Z350XT and Filtek P90 composites immersed in artificial saliva, respectively. The ΔE values of Filtek Z250 and Z350XT composites induced by Red Bull and Hype energy drinks were not significantly different. Discoloration of Filtek P90 was higher in Red Bull energy drink at both time points. Prolonged immersion time in all three solutions increased ΔE values of all composites. However, the ΔE values were within the clinically acceptable range (<3.3) at both time points.

Influence of storage duration and processing on chromatic attributes and flavonoid content of moxa floss.

PubMed

Lim, Min Yee; Huang, Jian; Zhao, Bai-xiao; Zou, Hui-qin; Yan, Yong-hong

2016-01-01

Moxibustion is an important traditional Chinese medicine therapy using heat from ignited moxa floss for disease treatment. The purpose of the present study is to establish a reproducible method to assess the color of moxa floss, discriminate the samples based on chromatic coordinates and explore the relationship between chromatic coordinates and total flavonoid content (TFC). Moxa floss samples of different storage years and production ratios were obtained from a moxa production factory in Henan Province, China. Chromatic coordinates (L*, a* and b*) were analyzed with an ultraviolet-visible spectrophotometer and the chroma (C*) and hue angle (h°) values were calculated. TFC was determined by a colorimetric method. Data were analyzed with correlation, principal component analysis (PCA). Significant differences in the chromatic values and TFC were observed among samples of different storage years and production ratios. Samples of higher production ratio displayed higher chromatic characteristics and lower TFC. Samples of longer storage years contained higher TFC. Preliminary separation of moxa floss production ratio was obtained by means of color feature maps developed using L*-a* or L*-b* as coordinates. PCA allowed the separation of the samples from their storage years and production ratios based on their chromatic characteristics and TFC. The use of a colorimetric technique and CIELAB coordinates coupled with chemometrics can be practical and objective for discriminating moxa floss of different storage years and production ratios. The development of color feature maps could be used as a model for classifying the color grading of moxa floss.

Influence of implant abutment material and ceramic thickness on optical properties.

PubMed

Jirajariyavej, Bundhit; Wanapirom, Peeraphorn; Anunmana, Chuchai

2018-05-01

Anterior shade matching is an essential factor influencing the esthetics of a ceramic restoration. Dentists face a challenge when the color of an implant abutment creates an unsatisfactory match with the ceramic restoration or neighboring teeth. The purpose of this in vitro study was to evaluate the influence of abutment material and ceramic thickness on the final color of different ceramic systems. Four experimental and control ceramic specimens in shade A3 were cut from IPS e.max CAD, IPS Empress CAD, and VITA Suprinity PC blocks. These specimens had thicknesses of 1.0 mm, 1.5 mm, 2.0 mm, and 2.5 mm, respectively, for the experimental groups, and 4 mm for the controls. Background abutment specimens were fabricated to yield 3 different shades: white zirconia, yellow zirconia, and titanium at a 3-mm thickness. All 3 ceramic specimens in each thickness were placed in succession on different abutment backgrounds with glycerin optical fluid in between, and the color was measured. A digital spectrophotometer was used to record the specimen color value in the Commission Internationale De L'éclairage (CIELab) color coordinates system and to calculate the color difference (ΔE) between the control and experimental groups. The Kruskal-Wallis test was used to analyze the effect of ceramic thickness on different abutments, and the pair-wise test was used to evaluate within the group (α=.05). The color differences between the test groups and the control decreased with increasing ceramic thickness for every background material. In every case, significant differences were found between 1.0- and 2.5-mm ceramic thicknesses. Only certain 2.5-mm e.max CAD, VITA Suprinity PC, and Empress CAD specimens on yellow-shade zirconia or VITA Suprinity PC on titanium were identified as clinically acceptable (ΔE<3). Increasing ceramic restoration thickness over the abutment background decreased the color mismatch. Increasing the thickness of ceramic on a yellow-shaded zirconia abutment rather than on titanium or white zirconia yielded a more esthetic color for the whole restoration. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Characterization and geographical discrimination of commercial Citrus spp. honeys produced in different Mediterranean countries based on minerals, volatile compounds and physicochemical parameters, using chemometrics.

PubMed

Karabagias, Ioannis K; Louppis, Artemis P; Karabournioti, Sofia; Kontakos, Stavros; Papastephanou, Chara; Kontominas, Michael G

2017-02-15

The objective of the present study was: i) to characterize Mediterranean citrus honeys based on conventional physicochemical parameter values, volatile compounds, and mineral content ii) to investigate the potential of above parameters to differentiate citrus honeys according to geographical origin using chemometrics. Thus, 37 citrus honey samples were collected during harvesting periods 2013 and 2014 from Greece, Egypt, Morocco, and Spain. Conventional physicochemical and CIELAB colour parameters were determined using official methods of analysis and the Commission Internationale de l' Eclairage recommendations, respectively. Minerals were determined using ICP-OES and volatiles using SPME-GC/MS. Results showed that honey samples analyzed, met the standard quality criteria set by the EU and were successfully classified according to geographical origin. Correct classification rates were 97.3% using 8 physicochemical parameter values, 86.5% using 15 volatile compound data and 83.8% using 13 minerals. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of coping design on the cervical color of ceramic crowns.

PubMed

Paniz, Gianluca; Kang, Ki-Ho; Kim, Yongjeong; Kumagai, Naota; Hirayama, Hiroshi

2013-12-01

The replication of natural teeth, especially with single-tooth restorations, represents a challenge. Similar to metal ceramic crowns, different designs of zirconia substructures have been suggested to improve the esthetic results of zirconia ceramic crowns. The purpose of the study was to analyze the color of the cervical portion of single zirconia ceramic crowns fabricated with different zirconia coping designs. The color, measured on the CIELAB color scale, of 3 different groups of restorations (n=10) fabricated with zirconia coping (Lava) and feldspathic porcelain (Noritake Super Porcelain) was analyzed with a spectrophotometer. Conventional zirconia crowns with zirconia facial margins were compared with ceramic crowns with porcelain facial margins and either a horizontal reduction of the zirconia coping (1.0 mm reduction) or an additional vertical reduction (1.0 mm additional reduction). The 3 groups, each with a different coping extension, were examined with a 1-way ANOVA and the Fisher exact test, and the differences of the groups were evaluated by applying ΔE thresholds (α=.05). The mean color difference among all the groups was not clinically significant (ΔE<3.7). Reduced color differences were present between the 2 porcelain butt margin groups of crowns (ΔE=1.06, between group H and V). Increased differences were present between the zirconia margin group and the porcelain butt margin group (ΔE=2.54 between group C and H; ΔE=2.41 between group C and V). Lab* values were examined in all the groups of crowns to determine the clinical implications. Within the limitation of the study, no significant differences were present among the tested groups of crowns. Nevertheless, although some differences were present between the zirconia margin group and the porcelain butt margin group, reduced differences were present between the 2 different cutback designs. Copyright © 2013 Editorial Council for the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Predicting Soil Organic Carbon and Total Nitrogen in the Russian Chernozem from Depth and Wireless Color Sensor Measurements

NASA Astrophysics Data System (ADS)

Mikhailova, E. A.; Stiglitz, R. Y.; Post, C. J.; Schlautman, M. A.; Sharp, J. L.; Gerard, P. D.

2017-12-01

Color sensor technologies offer opportunities for affordable and rapid assessment of soil organic carbon (SOC) and total nitrogen (TN) in the field, but the applicability of these technologies may vary by soil type. The objective of this study was to use an inexpensive color sensor to develop SOC and TN prediction models for the Russian Chernozem (Haplic Chernozem) in the Kursk region of Russia. Twenty-one dried soil samples were analyzed using a Nix Pro™ color sensor that is controlled through a mobile application and Bluetooth to collect CIEL*a*b* (darkness to lightness, green to red, and blue to yellow) color data. Eleven samples were randomly selected to be used to construct prediction models and the remaining ten samples were set aside for cross validation. The root mean squared error (RMSE) was calculated to determine each model's prediction error. The data from the eleven soil samples were used to develop the natural log of SOC (lnSOC) and TN (lnTN) prediction models using depth, L*, a*, and b* for each sample as predictor variables in regression analyses. Resulting residual plots, root mean square errors (RMSE), mean squared prediction error (MSPE) and coefficients of determination ( R 2, adjusted R 2) were used to assess model fit for each of the SOC and total N prediction models. Final models were fit using all soil samples, which included depth and color variables, for lnSOC ( R 2 = 0.987, Adj. R 2 = 0.981, RMSE = 0.003, p-value < 0.001, MSPE = 0.182) and lnTN ( R 2 = 0.980 Adj. R 2 = 0.972, RMSE = 0.004, p-value < 0.001, MSPE = 0.001). Additionally, final models were fit for all soil samples, which included only color variables, for lnSOC ( R 2 = 0.959 Adj. R 2 = 0.949, RMSE = 0.007, p-value < 0.001, MSPE = 0.536) and lnTN ( R 2 = 0.912 Adj. R 2 = 0.890, RMSE = 0.015, p-value < 0.001, MSPE = 0.001). The results suggest that soil color may be used for rapid assessment of SOC and TN in these agriculturally important soils.

Evaluation of a hyperspectral image database for demosaicking purposes

NASA Astrophysics Data System (ADS)

Larabi, Mohamed-Chaker; Süsstrunk, Sabine

2011-01-01

We present a study on the the applicability of hyperspectral images to evaluate color filter array (CFA) design and the performance of demosaicking algorithms. The aim is to simulate a typical digital still camera processing pipe-line and to compare two different scenarios: evaluate the performance of demosaicking algorithms applied to raw camera RGB values before color rendering to sRGB, and evaluate the performance of demosaicking algorithms applied on the final sRGB color rendered image. The second scenario is the most frequently used one in literature because CFA design and algorithms are usually tested on a set of existing images that are already rendered, such as the Kodak Photo CD set containing the well-known lighthouse image. We simulate the camera processing pipe-line with measured spectral sensitivity functions of a real camera. Modeling a Bayer CFA, we select three linear demosaicking techniques in order to perform the tests. The evaluation is done using CMSE, CPSNR, s-CIELAB and MSSIM metrics to compare demosaicking results. We find that the performance, and especially the difference between demosaicking algorithms, is indeed significant depending if the mosaicking/demosaicking is applied to camera raw values as opposed to already rendered sRGB images. We argue that evaluating the former gives a better indication how a CFA/demosaicking combination will work in practice, and that it is in the interest of the community to create a hyperspectral image dataset dedicated to that effect.

Evaluation of the Diode laser (810nm, 980 nm) on color change of teeth after external bleaching

PubMed Central

Kiomars, Nazanin; Azarpour, Pouneh; Mirzaei, Mansooreh; Hashemi kamangar, Sedighe Sadat; Kharazifard, Mohammad Javad

2016-01-01

Subject and aim: The aim of this study was to evaluate the efficiency of diode laser-activated bleaching systems for color change of teeth. Materials & Methods: 40 premolars with intact enamel surfaces were selected for five external bleaching protocols (n=8). Two different wavelengths of diode laser (810 and 980 nm) with two different hydrogen peroxide concentrations (30% and 46%) were selected for laser bleaching. Group 1 received bleaching (Heydent- Germany) with a 810 nm diode laser; Group 2 received bleaching (Heydent- Germany) with a 980 nm diode laser; Group 3 received bleaching (laser white*20- Biolase) with a 810 nm diode laser; Group 4 received bleaching (laser white*20- Biolase) with a 980 nm diode laser, with an output power of 1.5 W, in continuous wave (cw) mode for each irradiation. Group 5 as control group received 40% hydrogen peroxide (Opalescence Boost, Ultradent-USA) with no light activation. The color of teeth was scored at baseline and 1 week after bleaching with spectrophotometer. Color change data on the CIEL*a*b* system were analyzed statistically by the one-way ANOVA and Tukey's HSD test. Results: All the bleaching techniques resulted in shade change. According to ΔE values, all techniques were effective to bleach the teeth (ΔE ≥ 3). Statistically significant differences were detected among bleaching protocols (p=0.06). Regarding shade change values expressed as ΔL*, Δa*, Δb*, ΔE*, laser bleached groups were no statistically different with each other (p>0.05). Conclusion: Bleaching with different wavelengths of diode laser resulted in the same results. PMID:28765671

Evaluation of the Diode laser (810nm, 980 nm) on color change of teeth after external bleaching.

PubMed

Kiomars, Nazanin; Azarpour, Pouneh; Mirzaei, Mansooreh; Hashemi Kamangar, Sedighe Sadat; Kharazifard, Mohammad Javad; Chiniforush, Nasim

2016-12-30

Subject and aim: The aim of this study was to evaluate the efficiency of diode laser-activated bleaching systems for color change of teeth. Materials & Methods: 40 premolars with intact enamel surfaces were selected for five external bleaching protocols (n=8). Two different wavelengths of diode laser (810 and 980 nm) with two different hydrogen peroxide concentrations (30% and 46%) were selected for laser bleaching. Group 1 received bleaching (Heydent- Germany) with a 810 nm diode laser; Group 2 received bleaching (Heydent- Germany) with a 980 nm diode laser; Group 3 received bleaching (laser white*20- Biolase) with a 810 nm diode laser; Group 4 received bleaching (laser white*20- Biolase) with a 980 nm diode laser, with an output power of 1.5 W, in continuous wave (cw) mode for each irradiation. Group 5 as control group received 40% hydrogen peroxide (Opalescence Boost, Ultradent-USA) with no light activation. The color of teeth was scored at baseline and 1 week after bleaching with spectrophotometer. Color change data on the CIEL*a*b* system were analyzed statistically by the one-way ANOVA and Tukey's HSD test. Results: All the bleaching techniques resulted in shade change. According to ΔE values, all techniques were effective to bleach the teeth (ΔE ≥ 3). Statistically significant differences were detected among bleaching protocols (p=0.06). Regarding shade change values expressed as ΔL*, Δa*, Δb*, ΔE*, laser bleached groups were no statistically different with each other (p>0.05). Conclusion: Bleaching with different wavelengths of diode laser resulted in the same results.

Effect of Energy Drinks on Discoloration of Silorane and Dimethacrylate-Based Composite Resins

PubMed Central

Ahmadizenouz, Ghazaleh; Esmaeili, Behnaz; Ahangari, Zohreh; Khafri, Soraya; Rahmani, Aghil

2016-01-01

Objectives: This study aimed to assess the effects of two energy drinks on color change (ΔE) of two methacrylate-based and a silorane-based composite resin after one week and one month. Materials and Methods: Thirty cubic samples were fabricated from Filtek P90, Filtek Z250 and Filtek Z350XT composite resins. All the specimens were stored in distilled water at 37°C for 24 hours. Baseline color values (L*a*b*) of each specimen were measured using a spectrophotometer according to the CIEL*a*b* color system. Ten randomly selected specimens from each composite were then immersed in the two energy drinks (Hype, Red Bull) and artificial saliva (control) for one week and one month. Color was re-assessed after each storage period and ΔE values were calculated. The data were analyzed using the Kruskal Wallis and Mann–Whitney U tests. Results: Filtek Z250 composite showed the highest ΔE irrespective of the solutions at both time points. After seven days and one month, the lowest ΔE values were observed in Filtek Z350XT and Filtek P90 composites immersed in artificial saliva, respectively. The ΔE values of Filtek Z250 and Z350XT composites induced by Red Bull and Hype energy drinks were not significantly different. Discoloration of Filtek P90 was higher in Red Bull energy drink at both time points. Conclusions: Prolonged immersion time in all three solutions increased ΔE values of all composites. However, the ΔE values were within the clinically acceptable range (<3.3) at both time points. PMID:28127318

Placebo-controlled clinical trial of use of 10% hydrogen peroxide whitening strips for medication-induced xerostomia.

PubMed

Papas, Athena S; Kugel, Gerard; Singh, Mabi; Barker, Matthew L; Gerlach, Robert W

2009-01-01

A randomized, double-blind, placebo-controlled clinical trial was conducted to evaluate the effectiveness and safety of peroxide-containing strip-based tooth whitening among subjects with medication-induced hyposalivation. Eligibility for this tooth whitening study was limited to dentate adults taking xerogenic medications with an unstimulated salivary flow < or = 0.2 ml/min. After giving informed consent, 42 subjects were randomized using a 2:1 ratio to 10% hydrogen peroxide whitening strips (Crest Whitestrips Premium) or placebo strips without peroxide. Strips were used for 30 min twice daily for a 14-day period. Usage was unsupervised, and only the maxillary arch was treated. On days 8 and 15, efficacy was assessed from standard digital images of the anterior dentition and quantified using the Cielab color system, while safety was assessed from interviews and clinical examinations. At day 8, the peroxide group experienced significant (p < 0.001) color improvement relative to baseline and placebo. Adjusted means +/- standard errors for yellowness reduction were -1.65 +/- 0.115 units for the peroxide group and -0.32 +/- 0.170 units for the placebo group. For the increase in lightness, adjusted means +/- standard errors on day 8 were 1.53 +/- 0.130 units for the peroxide group and 0.37 +/- 0.191 units for the controls. Continued strip use through day 15 yielded incremental color improvement for the peroxide group. Mild and transient tooth sensitivity represented the most common adverse events. No subject discontinued treatment due to a product-related adverse event. Twice daily use of 10% hydrogen peroxide whitening strips by adults with medication-induced xerostomia was well tolerated, with significant tooth color improvement evident within 7 days. Copyright 2009 S. Karger AG, Basel.

The role of enamel thickness and refractive index on human tooth colour.

PubMed

Oguro, Rena; Nakajima, Masatoshi; Seki, Naoko; Sadr, Alireza; Tagami, Junji; Sumi, Yasunori

2016-08-01

To investigate the role of enamel thickness and refractive index (n) on tooth colour. The colour and enamel thickness of fifteen extracted human central incisors were determined according to CIELab colour scale using spectrophotometer (Crystaleye) and swept-source optical coherence tomography (SS-OCT), respectively. Subsequently, labial enamel was trimmed by approximately 100μm, and the colour and remaining enamel thickness were investigated again. This cycle was repeated until dentin appeared. Enamel blocks were prepared from the same teeth and their n were obtained using SS-OCT. Multiple regression analysis was performed to reveal any effects of enamel thickness and n on colour difference (ΔE00) and differences in colour parameters with CIELCh and CIELab colour scales. Multiple regression analysis revealed that enamel thickness (p=0.02) and n of enamel (p<0.001) were statistically significant predictors of ΔE00 after complete enamel trimming. The n was also a significant predictor of ΔH' (p=0.01). Enamel thickness and n were not statistically significant predictors of ΔL', ΔC', Δa* and Δb*. Enamel affected tooth colour, in which n was a statistically significant predictor for tooth colour change. Understanding the role of enamel in tooth colour could contribute to development of aesthetic restorative materials that mimic the colour of natural tooth with minimal reduction of the existing enamel. Copyright © 2016 Elsevier Ltd. All rights reserved.

Genome-wide association study of pigmentary traits (skin and iris color) in individuals of East Asian ancestry.

PubMed

Rawofi, Lida; Edwards, Melissa; Krithika, S; Le, Phuong; Cha, David; Yang, Zhaohui; Ma, Yanyun; Wang, Jiucun; Su, Bing; Jin, Li; Norton, Heather L; Parra, Esteban J

2017-01-01

Currently, there is limited knowledge about the genetics underlying pigmentary traits in East Asian populations. Here, we report the results of the first genome-wide association study of pigmentary traits (skin and iris color) in individuals of East Asian ancestry. We obtained quantitative skin pigmentation measures (M-index) in the inner upper arm of the participants using a portable reflectometer ( N  = 305). Quantitative measures of iris color (expressed as L*, a* and b* CIELab coordinates) were extracted from high-resolution iris pictures ( N  = 342). We also measured the color differences between the pupillary and ciliary regions of the iris (e.g., iris heterochromia). DNA samples were genotyped with Illumina's Infinium Multi-Ethnic Global Array (MEGA) and imputed using the 1000 Genomes Phase 3 samples as reference haplotypes. For skin pigmentation, we did not observe any genome-wide significant signal. We followed-up in three independent Chinese samples the lead SNPs of five regions showing multiple common markers (minor allele frequency ≥ 5%) with good imputation scores and suggestive evidence of association ( p -values < 10 -5 ). One of these markers, rs2373391, which is located in an intron of the ZNF804B gene on chromosome 7, was replicated in one of the Chinese samples ( p  = 0.003). For iris color, we observed genome-wide signals in the OCA2 region on chromosome 15. This signal is driven by the non-synonymous rs1800414 variant, which explains 11.9%, 10.4% and 6% of the variation observed in the b*, a* and L* coordinates in our sample, respectively. However, the OCA2 region was not associated with iris heterochromia. Additional genome-wide association studies in East Asian samples will be necessary to further disentangle the genetic architecture of pigmentary traits in East Asian populations.

[Effect of three kinds of rare earth oxides on chromaticity and mechanical properties of zirconia ceramic].

PubMed

Huang, Hui; Zhang, Fu-qiang; Sun, Jing; Gao, Lian

2006-06-01

To evaluate the colouration of zirconia ceramic by adding three kinds of rare earth oxides. The influence of the pigments concentration on the mechanical properties and the microstructure was also analyzed. Added different concentrations of CeO(2), Er(2)O(3) and Pr(6)O(11) in tetragonal zirconia poly crystals stabilized with 3 mol% yttria (3Y-T2P) powder, compacted at 200 MPa using cold isostatic pressure, and sintered to 1 400 degrees C. The heating rate was 150 degrees C/h and the dwelling time was 2 hours. The chromaticity of sintered bodies was measured with chroma meter. The relative density, hardness, flexure strength and fracture toughness were investigated as well. The phase stability of the colorized and pure zirconia was evaluated by X-ray diffraction (XRD) using an automated diffractometer. The microstructures of the specimens were evaluated by scanning electron microscope (SEM). Several kinds of color achieved by the different pigments praseodym oxide, cerium oxide and erbium oxide were presented in the CIELab system. The a* value increased with the added amount of Er(2)O(3), while b* value rose with the increasing amount of CeO(2) and Pr(6)O(11). However, three pigments failed to decrease L* value and the sintered body appeared too bright. Adding three pigments influenced flexure strength of zirconia ceramic significantly, but had little influence on the hardness and fracture toughness. Microscopy revealed the relationship between the porosity and shapes of grains was correlated to strength of the diphase ceramics. No additional phase could be detected by XRD, except t-ZrO(2) in all colorized samples after sintering at 1 400 degrees C for 120 min. Zirconia ceramic can be colorized by CeO(2), Er(2)O(3), and Pr(6)O(11). Pigments even in a small amount influence the mechanical properties of the colorized zirconia material, which necessitates further investigation.

Genome-wide association study of pigmentary traits (skin and iris color) in individuals of East Asian ancestry

PubMed Central

Rawofi, Lida; Edwards, Melissa; Krithika, S; Le, Phuong; Cha, David; Yang, Zhaohui; Ma, Yanyun; Wang, Jiucun; Su, Bing; Jin, Li; Norton, Heather L.

2017-01-01

Background Currently, there is limited knowledge about the genetics underlying pigmentary traits in East Asian populations. Here, we report the results of the first genome-wide association study of pigmentary traits (skin and iris color) in individuals of East Asian ancestry. Methods We obtained quantitative skin pigmentation measures (M-index) in the inner upper arm of the participants using a portable reflectometer (N = 305). Quantitative measures of iris color (expressed as L*, a* and b* CIELab coordinates) were extracted from high-resolution iris pictures (N = 342). We also measured the color differences between the pupillary and ciliary regions of the iris (e.g., iris heterochromia). DNA samples were genotyped with Illumina’s Infinium Multi-Ethnic Global Array (MEGA) and imputed using the 1000 Genomes Phase 3 samples as reference haplotypes. Results For skin pigmentation, we did not observe any genome-wide significant signal. We followed-up in three independent Chinese samples the lead SNPs of five regions showing multiple common markers (minor allele frequency ≥ 5%) with good imputation scores and suggestive evidence of association (p-values < 10−5). One of these markers, rs2373391, which is located in an intron of the ZNF804B gene on chromosome 7, was replicated in one of the Chinese samples (p = 0.003). For iris color, we observed genome-wide signals in the OCA2 region on chromosome 15. This signal is driven by the non-synonymous rs1800414 variant, which explains 11.9%, 10.4% and 6% of the variation observed in the b*, a* and L* coordinates in our sample, respectively. However, the OCA2 region was not associated with iris heterochromia. Discussion Additional genome-wide association studies in East Asian samples will be necessary to further disentangle the genetic architecture of pigmentary traits in East Asian populations. PMID:29109912

Influence of the color of composite resin foundation and luting cement on the final color of lithium disilicate ceramic systems.

PubMed

Dede, Doğu Ömür; Sahin, Onur; Özdemir, Oğuz Süleyman; Yilmaz, Burak; Celik, Ersan; Köroğlu, AySegül

2017-01-01

Lithium disilicate restorations are commonly used, particularly in the anterior region. The color of the underlying composite resin foundation (CRF) and luting cement may negatively affect the color of lithium disilicate ceramic restorations. The purpose of this in vitro study was to investigate the effect of CRF and resin cement materials on the color of lithium disilicate ceramics in 2 different translucencies. Twenty disks (11×1.5 mm, shade A2) were fabricated from medium-opacity (mo) (n=10) and high-translucency (ht) (n=10) lithium disilicate (Lds) blocks (IPS e.max Press). Five CRF disks (11×3 mm) were fabricated in 5 different shades (A1, A2, A3, B2, C2) and 30 resin cement disks (11×0.2 mm) in the shades of translucent (Tr), universal (Un=A2), and white-opaque (Wo). Ceramic specimens were placed on each CRF, and the resin cement combination and color was measured with a spectrophotometer. CIELAB color coordinates were recorded, and the color coordinates of both ceramics on the shades of the A2 CRF and resin cement were saved as the control. Color differences (ΔE 00 ) between the control and test groups were calculated. Data were analyzed with 3-way analysis ANOVA and compared with the Tukey HSD test (α=.05). The ΔE 00 values were influenced by the shades of the CRF, resin cement materials, and also their interactions (P<.05). The ΔE 00 values were not affected by the ceramic type. The ΔE 00 values of the Wo cement groups (1.73 to 2.96) were significantly higher than those of the other cement shades (0.88 to 1.29) for each ceramic type and CRF shade (P<.05). Lithium disilicate ceramics in 2 different translucencies were similarly influenced by the color of the underlying cement and CRF. When translucent and universal cement shades were used, the core shade did not affect the final color of the ceramics. White opaque cement caused clinically unacceptable color changes in both ceramics on all shades of CRFs except the C2 CRF and when high translucency ceramic was used on the A2 CRF. These changes were clinically acceptable, but perceptible. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Effect of different carotenoid-containing diets on the vitamin A levels and colour parameters in Iberian pigs' tissues: utility as biomarkers of traceability.

PubMed

Álvarez, R; Vicario, I M; Meléndez-Martínez, A J; Alcalde, M J

2014-10-01

Retinol and fat colour parameters in Iberian pigs fed on different carotenoid-containing diets were assessed. Thirty animals in two groups were considered: Iberian breed pigs fed on acorns and grass (Montanera) and on concentrate (Cebo). Carotenoids and retinoids were analysed in the diets and in plasma, liver and perirenal fat of the animals by HPLC and HPLC-MS. Retinol levels in plasma and fat were similar in Montanera and Cebo animals. The utility of retonids and colour parameters as traceability index was also explored. Retinoids in liver classified correctly 93% of the animals according to their diet L* and hab. CIELAB parameters of the perirenal fat discriminated correctly 78.6% of the animals according to their diet. L* values for the Montanera animals were significantly different (P<0.01) from those fed on concentrate. It can be claimed that the liver retinol profile and fat colour parameters can be useful for feeding traceability purposes in Iberian pigs breed in Montanera and Cebo. Copyright © 2014 Elsevier Ltd. All rights reserved.

Spectrophotometric Analysis of Phenolic Compounds in Grapes and Wines.

PubMed

Aleixandre-Tudo, Jose Luis; Buica, Astrid; Nieuwoudt, Helene; Aleixandre, Jose Luis; du Toit, Wessel

2017-05-24

Phenolic compounds are of crucial importance for red wine color and mouthfeel attributes. A large number of enzymatic and chemical reactions involving phenolic compounds take place during winemaking and aging. Despite the large number of published analytical methods for phenolic analyses, the values obtained may vary considerably. In addition, the existing scientific knowledge needs to be updated, but also critically evaluated and simplified for newcomers and wine industry partners. The most used and widely cited spectrophotometric methods for grape and wine phenolic analysis were identified through a bibliometric search using the Science Citation Index-Expanded (SCIE) database accessed through the Web of Science (WOS) platform from Thompson Reuters. The selection of spectrophotometry was based on its ease of use as a routine analytical technique. On the basis of the number of citations, as well as the advantages and disadvantages reported, the modified Somers assay appears as a multistep, simple, and robust procedure that provides a good estimation of the state of the anthocyanins equilibria. Precipitation methods for total tannin levels have also been identified as preferred protocols for these types of compounds. Good reported correlations between methods (methylcellulose precipitable vs bovine serum albumin) and between these and perceived red wine astringency, in combination with the adaptation to high-throughput format, make them suitable for routine analysis. The bovine serum albumin tannin assay also allows for the estimation of the anthocyanins content with the measurement of small and large polymeric pigments. Finally, the measurement of wine color using the CIELab space approach is also suggested as the protocol of choice as it provides good insight into the wine's color properties.

Effects of the type and thickness of ceramic, substrate, and cement on the optical color of a lithium disilicate ceramic.

PubMed

Pires, Laís A; Novais, Pollyanna M R; Araújo, Vinícius D; Pegoraro, Luiz F

2017-01-01

Reproducing the characteristics of natural teeth in ceramic crowns remains a complex and difficult process. The purpose of this in vitro study was to evaluate the effect of the substrate, cement, type, and thickness of the ceramic on the resulting color of a lithium disilicate ceramic. Forty ceramic disks were prepared from IPS e.max Press LT (low translucency) and HO (high opacity) in 2 different thicknesses (1.5 and 2 mm). The LT groups were composed of monolithic ceramic disks, and the HO groups were composed of disks fabricated with a 0.5-mm thickness combined with a 1- or 1.5-mm veneering ceramic thickness. Disks made of composite resin (R) and alloy (A) were used as substrate structures. The resin cement used was Variolink II. Color was measured with a spectrophotometer and expressed in CIELAB coordinates. Color differences (ΔE) were calculated. The data were analyzed with ANOVA and the Tukey HSD test (α=.05). When the ΔE of ceramic disks with both substrates, with and without cement, were compared, the lowest value (3) was obtained for ceramic HO with a 2-mm thickness/alloy substrate/without cement; the highest value (10) was obtained for ceramic LT with a1.5-mm thickness/alloy substrate/with cement. This difference was statistically significant. When the effect of cement on the ΔE of ceramics in both substrates was compared, the lowest value (1.1) occurred with ceramic HO with a 1.5-mm thickness/resin substrate, and the highest was observed for ceramic LT with a 1.5-mm thickness/alloy substrate (6.4). This difference was statistically significant. The substrate color, type and thickness of ceramic, and presence of the cement significantly influenced the resulting optical color. The ΔE values of cemented HO ceramics were lower than that of the LT ceramic. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Association between masticatory performance using a colour-changeable chewing gum and jaw movement.

PubMed

Komagamine, Y; Kanazawa, M; Minakuchi, S; Uchida, T; Sasaki, Y

2011-08-01

The purpose of this study was to investigate the relationship between masticatory performance as determined using a colour-changeable chewing gum and mandibular movements. Subjects comprised 45 fully dentate adults (23 men, 22 women; mean age, 28·1 years). The gum was chewed for a specified number of chewing strokes (20, 40, 60, 80, 120 or 160 strokes) without any instructions as to chewing side. A colourimeter was used to measure L*, a* and b* values (CIE-L*a*b* colour system) for the chewed gum, then the difference between two colours in the CIE-L*a*b* colour space (ΔE) for each number of chewing strokes was calculated according to a formula. Index of masticatory performance (ΔE60) for each subject was obtained using ΔE for 20, 40, 60, 80, 120 and 160 strokes. Mandibular movements were recorded using an opto-electric system with six degrees of freedom. Twelve parameters of mandibular movements relating to amplitude, duration, velocity and angle were computed for each cycle, and mean values for 10 cycles (from cycle 11 to 20) were calculated separately. Stepwise multiple regression analysis identified maximum closing velocity and closing angle as predictors accounting for 18% of the variation in ΔE60. These results suggest that lower angles of approach to intercuspation and faster speed during closing duration are associated with colour changes in the colour-changeable chewing gum. © 2011 Blackwell Publishing Ltd.

New isotonic drinks with antioxidant and biological capacities from berries (maqui, açaí and blackthorn) and lemon juice.

PubMed

Gironés-Vilaplana, Amadeo; Villaño, Débora; Moreno, Diego A; García-Viguera, Cristina

2013-11-01

The aim of the study was to design new isotonic drinks with lemon juice and berries: maqui [Aristotelia chilensis (Molina) Stuntz], açaí (Euterpe oleracea Mart.) and blackthorn (Prunus spinosa L.), following on from previous research. Quality parameters - including colour (CIELab parameters), minerals, phytochemical identification and quantification by high-performance liquid chromatography with diode array detector, total phenolic content by the Folin-Ciocalteu reagent, the antioxidant capacity (ABTS(+), DPPH• and [Formula: see text] assays) and biological activities (in vitro alpha-glucosidase and lipase inhibitory effects) - were tested in the samples and compared to commercially available isotonic drinks. The new isotonic blends with lemon and anthocyanins-rich berries showed an attractive colour, especially in maqui samples, which is essential for consumer acceptance. Significantly higher antioxidant and biological effects were determined in the new blends, in comparison with the commercial isotonic beverages.

Inhibition of polyphenol oxidases activity by various dipeptides.

PubMed

Girelli, Anna M; Mattei, Enrico; Messina, Antonella; Tarola, Anna M

2004-05-19

In an effort to develop natural and nontoxic inhibitors on the activity of mushroom polyphenol oxidase (PPO) the effect of various glycyl-dipeptides (GlyAsp, GlyGly, GlyHis, GlyLeu, GlyLys, GlyPhe, GlyPro, GlyTyr) was investigated. The inhibition study with dihydroxyphenylalanine (DOPA) as substrate is based on separation of the enzymatic reaction components by reversed phase HPLC and the UV detection of the dopachrome formed. The results have evidenced that several of tested dipeptides inhibited PPO activity in the range of 20-40% while GlyPro and GlyLeu had no effect. The study has also permitted the characterization of the following kinetic pattern: a linear-mixed-type mechanism for GlyAsp, GlyGly, GlyLys, and GlyPhe and a hyperbolic-mixed-type for GlyTyr. It was not possible to identify the inhibition mechanism for GlyHis, although it affects PPO activity. In addition the effects of GlyAsp, GlyLys and GlyHis were evaluated for lessening the browning of fresh Golden Delicious apple and Irish White Skinned potato. The effectiveness of such inhibitors was determined by the difference between the colors observed in the dipeptide-treated sample and the controls using the color space CIE-Lab system. The % browning inhibition on potato (20-50%) was greater than of apple (20-30%) by the all tested dipeptides. Only GlyLys presented the significant value of 50%.

Decorative black TiCxOy film fabricated by DC magnetron sputtering without importing oxygen reactive gas

NASA Astrophysics Data System (ADS)

Ono, Katsushi; Wakabayashi, Masao; Tsukakoshi, Yukio; Abe, Yoshiyuki

2016-02-01

Decorative black TiCxOy films were fabricated by dc (direct current) magnetron sputtering without importing the oxygen reactive gas into the sputtering chamber. Using a ceramic target of titanium oxycarbide (TiC1.59O0.31), the oxygen content in the films could be easily controlled by adjustment of total sputtering gas pressure without remarkable change of the carbon content. The films deposited at 2.0 and 4.0 Pa, those are higher pressure when compared with that in conventional magnetron sputtering, showed an attractive black color. In particular, the film at 4.0 Pa had the composition of TiC1.03O1.10, exhibited the L* of 41.5, a* of 0.2 and b* of 0.6 in CIELAB color space. These values were smaller than those in the TiC0.29O1.38 films (L* of 45.8, a* of 1.2 and b* of 1.2) fabricated by conventional reactive sputtering method from the same target under the conditions of gas pressure of 0.3 Pa and optimized oxygen reactive gas concentration of 2.5 vol.% in sputtering gas. Analysis of XRD and XPS revealed that the black film deposited at 4.0 Pa was the amorphous film composed of TiC, TiO and C. The adhesion property and the heat resisting property were enough for decorative uses. This sputtering process has an industrial advantage that the decorative black coating with color uniformity in large area can be easily obtained by plain operation because of unnecessary of the oxygen reactive gas importing which is difficult to be controlled uniformly in the sputtering chamber.

Carotenoid pixels characterization under color space tests and RGB formulas for mesocarp of mango's fruits cultivars

NASA Astrophysics Data System (ADS)

Hammad, Ahmed Yahya; Kassim, Farid Saad Eid Saad

2010-01-01

This study experimented the pulp (mesocarp) of fourteen cultivars were healthy ripe of Mango fruits (Mangifera indica L.) selected after picking from Mango Spp. namely Taimour [Ta], Dabsha [Da], Aromanis [Ar], Zebda [Ze], Fagri Kelan [Fa], Alphonse [Al], Bulbek heart [Bu], Hindi- Sinnara [Hi], Compania [Co], Langra [La], Mestikawi [Me], Ewais [Ew], Montakhab El Kanater [Mo] and Mabroka [Ma] . Under seven color space tests included (RGB: Red, Green and Blue), (CMY: Cyan, Magenta and Yellow), (CMY: Cyan, Magenta and Yellow), (HSL: Hue, Saturation and Lightness), (CMYK%: Cyan%, Magenta%, Yellow% and Black%), (HSV: Hue, Saturation and Value), (HºSB%: Hueº, Saturation% and Brightness%) and (Lab). (CMY: Cyan, Magenta and Yellow), (HSL: Hue, Saturation and Lightness), (CMYK%: Cyan%, Magenta%, Yellow% and Black%), (HSV: Hue, Saturation and Value), (HºSB%: Hueº, Saturation% and Brightness%) and (Lab). Addition, nine formula of color space tests included (sRGB 0÷1, CMY, CMYK, XYZ, CIE-L*ab, CIE-L*CH, CIE-L*uv, Yxy and Hunter-Lab) and (RGB 0÷FF/hex triplet) and Carotenoid Pixels Scale. Utilizing digital color photographs as tool for obtainment the natural color information for each cultivar then the result expounded with chemical pigment estimations. Our location study in the visual yellow to orange color degrees from the visible color of electromagnetic spectrum in wavelength between (~570 to 620) nm and frequency between (~480 to 530) THz. The results found carotene very strong influence in band Red while chlorophyll (a & b) was very lower subsequently, the values in band Green was depressed. Meanwhile, the general ratios percentage for carotenoid pixels in bands Red, Green and Blue were 50%, 39% and 11% as orderliness opposite the ratios percentage for carotene, chlorophyll a and chlorophyll b which were 63%, 22% and 16% approximately. According to that the pigments influence in all color space tests and RGB formulas. Band Yellow% in color test (CMYK%) as signature color for carotene. Bands K% and band C were equal zero in almost cells indicted to a mystical induction for chlorophyll (a & b). The results detection two bands regard as numeric chromatic filter. In RGB formulas the digits of carotenoid pixels under the effects of the various bands followed two characters including (Separation and Isotopic) effects these consider numeric chromatography. Digits of carotenoid pixels physically are disparate the trend and features under each band mostly. The RGB formulas present treatment for the symmetrically values in the columns data of the total pigments percentage and color space tests. Our objective physical study for pigments carotene to present standard evolution for pigment estimations. Addition to study the possibility to obtainment numeric chromatography for separation accuracy of the pigments.

Quality issues in blue noise halftoning

NASA Astrophysics Data System (ADS)

Yu, Qing; Parker, Kevin J.

1998-01-01

The blue noise mask (BNM) is a halftone screen that produces unstructured visually pleasing dot patterns. The BNM combines the blue-noise characteristics of error diffusion and the simplicity of ordered dither. A BNM is constructed by designing a set of interdependent binary patterns for individual gray levels. In this paper, we investigate the quality issues in blue-noise binary pattern design and mask generation as well as in application to color reproduction. Using a global filtering technique and a local 'force' process for rearranging black and white pixels, we are able to generate a series of binary patterns, all representing a certain gray level, ranging from white-noise pattern to highly structured pattern. The quality of these individual patterns are studied in terms of low-frequency structure and graininess. Typically, the low-frequency structure (LF) is identified with a measurement of the energy around dc in the spatial frequency domain, while the graininess is quantified by a measurement of the average minimum distance (AMD) between minority dots as well as the kurtosis of the local kurtosis distribution (KLK) for minority pixels of the binary pattern. A set of partial BNMs are generated by using the different patterns as unique starting 'seeds.' In this way, we are able to study the quality of binary patterns over a range of gray levels. We observe that the optimality of a binary pattern for mask generation is related to its own quality mertirc values as well as the transition smoothness of those quality metric values over neighboring levels. Several schemes have been developed to apply blue-noise halftoning to color reproduction. Different schemes generate halftone patterns with different textures. In a previous paper, a human visual system (HVS) model was used to study the color halftone quality in terms of luminance and chrominance error in CIELAB color space. In this paper, a new series of psycho-visual experiments address the 'preferred' color rendering among four different blue noise halftoning schemes. The experimental results will be interpreted with respect to the proposed halftone quality metrics.

Effect of addition of commercial grape seed tannins on phenolic composition, chromatic characteristics, and antioxidant activity of red wine.

PubMed

Neves, Ana C; Spranger, Maria I; Zhao, Yuqing; Leandro, Maria C; Sun, Baoshan

2010-11-24

The effect of addition of grape seed tannins on the phenolic composition, chromatic characteristics, and antioxidant activity of red wine was studied. Two highly pure commercial grape seed tannins (GSE100 and GSE300) were selected, and their phenolic compositions were determined. Two types of red wines were made with Castelão/Tinta Miúda (3/2, w/w) grapevine varieties by fermentation on skin using two different maceration times, which correspond to the wines rich and poor in polyphenols, respectively. Each of these wines was used for experimentation with the addition of GSE100 and GSE300 before and immediately after alcoholic fermentation. Phenolic composition, chromatic characteristics, and antioxidant activity of the finished red wines were analyzed by HPLC-DAD, CIElab 76 convention, and DPPH radical test, respectively. The results showed that the addition of grape seed tannins had obvious effects of increasing color intensity and antioxidant activity only in the wines poor in polyphenols. Although GSE300 contained much higher amounts of di- and trimer procyanidins and a lower amount of polymeric proanthocyanidins, it provided effects of increasing the color intensity and antioxidant activity of the wines poor in polyphenols similar to those of GSE100. Furthermore, GSE100 released more gallic acid to wines than GSE300, although no gallic acid was detected in GSE100. Tannins added after alcoholic fermentation had a better effect on phenolic composition of red wine than tannins added before alcoholic fermentation.

Individual Colorimetric Observer Model

PubMed Central

Asano, Yuta; Fairchild, Mark D.; Blondé, Laurent

2016-01-01

This study proposes a vision model for individual colorimetric observers. The proposed model can be beneficial in many color-critical applications such as color grading and soft proofing to assess ranges of color matches instead of a single average match. We extended the CIE 2006 physiological observer by adding eight additional physiological parameters to model individual color-normal observers. These eight parameters control lens pigment density, macular pigment density, optical densities of L-, M-, and S-cone photopigments, and λmax shifts of L-, M-, and S-cone photopigments. By identifying the variability of each physiological parameter, the model can simulate color matching functions among color-normal populations using Monte Carlo simulation. The variabilities of the eight parameters were identified through two steps. In the first step, extensive reviews of past studies were performed for each of the eight physiological parameters. In the second step, the obtained variabilities were scaled to fit a color matching dataset. The model was validated using three different datasets: traditional color matching, applied color matching, and Rayleigh matches. PMID:26862905

[Investigation of the function of the glass colorant on the machinable infiltrated ceramics color].

PubMed

Yang, Xiao-Yu; Liu, Chang-Hong; Liao, Yun-Mao; Xian, Su-Qin; Gao, Wen-Feng

2006-06-01

To investigae the function of the glass colorant on the color of the machinable infiltrated ceramics(MIC). Five kinds of glass with different colorant were infiltrated through the aluminous matrix by heating the components to 1 100 degrees C for 2 hours. The specimens surface was polished, and their thickness was 0.5 mm. The refractive index of the MIC infiltration glass was 1.59691 (587.6 nm, nd) . The most different parameter of the MIC color were L*, then a*, and b* had little difference . The parameters of the color space of MIC were: L*(64.55-71.46), a*(3.35-7.38), b*(10.00-12.41), Ca*b*(11.38-13.95), ha*b*(54.07-73.00). These were almost close to the color parameters of Vita In-ceram. This experiment proved that the glass colorant was changed the MIC color parameters, and the main function was on L*, then a*. The ceramic color was up to the requirement of clinic.

[Product development on the basis of cereal and leguminous flours to coeliac disease in children aged 6-24 months; II: properties of the mixtures].

PubMed

Cerezal Mezquita, P; Urtuvia Gatica, V; Ramírez Quintanilla, V; Arcos Zavala, R

2011-01-01

The nutritional formulations of high protein content, provided by a flour mixture from two Andean cultures, quinua (Chenopodium quinua Willd) and lupino (Lupinus albus L), with two traditional cereals, maize (Zea mays L.) and rice (Oryza sativa L.), entailed to the preparation of a "sweet mixture" for the elaboration of "queques" and another "dessert mixture" flavoured with banana, that can be prepared with water or milk, constituted a good alternative as food supplement for the nutrition of children aged 6-24 months who suffer from celiac disease, since they contribute to the quality improvement of the protein, by essential amino acids compensation, they are of low cost and allow an increase in availability of products for gluten-intolerant children. Some physical, chemical, rheological, mechanical and fluidity properties, as well as the color of these mixtures for a period of conservation of 90 days were evaluated. At the end of the storage, the sweet mixture turned out to be of "little flow" and the dessert mixture changed from "little flow" to "easy flow". Viscosity for the dessert mixture, with its two types of dilutions, water and milk, presented a behavior of pseudoplastic fluid. It was possible to guess that the time of shelf life of the mixtures would be of 9 months before achieving the rancidity limit (10 mEq of oxigen/kg of fat, which would disqualify the product for consumption). The CIEL*a*b* color coordinates did not show significant differences keeping the colour in "a beige" tonality.

The Tooth and Skin Colour Interrelationship across the Different Ethnic Groups

PubMed Central

Haralur, Satheesh B.; Dibas, Ahmed Mohammed; Almelhi, Nabil Abdullah; Al-Qahtani, Dhafer Ali

2014-01-01

Objectives. The purpose of the study was to investigate the relation between skin and tooth colour parameters in various ethnic groups. Materials and Methods. Saudi Arabian, Indian, African, and East Asian ethnic groups of 75 each were included in the study. The tooth colour was determined by spectrophotometer in CIELAB parameters. The skin colour was measured at earlobe, forehead, and malar locations by clinical skin photography. The data was statistically analysed by one-way ANOVA and correlation tests. Results. The “L” vale for the Saudi Arabian group had a strong correlation at earlobe location (r = 0.275), while correlation was found at forehead (r = 0.271) and malar region (r = 0.261) with Indian ethnic group. A strong negative correlation was observed in African ethnic group at all three locations for “L” parameter. The redness value “a” is found to have strong negative linear correlation between the earlobe and tooth for Saudi Arabian (r = −0.240) and Indian ethnic groups (r = −0.268). The “b” showed no correlation with skin location in all groups except positive correlation in African ethnic groups. Conclusions. The strong correlation was found between the skin and tooth colour parameters; hence the skin colour can be used as a guide for artificial tooth selection in edentulous patients. PMID:25101125

The Tooth and Skin Colour Interrelationship across the Different Ethnic Groups.

PubMed

Haralur, Satheesh B; Dibas, Ahmed Mohammed; Almelhi, Nabil Abdullah; Al-Qahtani, Dhafer Ali

2014-01-01

Objectives. The purpose of the study was to investigate the relation between skin and tooth colour parameters in various ethnic groups. Materials and Methods. Saudi Arabian, Indian, African, and East Asian ethnic groups of 75 each were included in the study. The tooth colour was determined by spectrophotometer in CIELAB parameters. The skin colour was measured at earlobe, forehead, and malar locations by clinical skin photography. The data was statistically analysed by one-way ANOVA and correlation tests. Results. The "L" vale for the Saudi Arabian group had a strong correlation at earlobe location (r = 0.275), while correlation was found at forehead (r = 0.271) and malar region (r = 0.261) with Indian ethnic group. A strong negative correlation was observed in African ethnic group at all three locations for "L" parameter. The redness value "a" is found to have strong negative linear correlation between the earlobe and tooth for Saudi Arabian (r = -0.240) and Indian ethnic groups (r = -0.268). The "b" showed no correlation with skin location in all groups except positive correlation in African ethnic groups. Conclusions. The strong correlation was found between the skin and tooth colour parameters; hence the skin colour can be used as a guide for artificial tooth selection in edentulous patients.

A clinical study relating CIELCH coordinates to the color dimensions of the 3D-Master System in a Spanish population.

PubMed

Gómez-Polo, Cristina; Gómez-Polo, Miguel; Celemín Viñuela, Alicia; Martínez Vázquez de Parga, Juan Antonio

2015-03-01

The 3D-Master System comprises 26 physical shade tabs and intermediate shades. Determining the relationship among all the groups of lightness, chroma, and hue of the 3D-Master System (Vita Zahnfabrik) and the L*, C*, and h* coordinates is important, because according to the manufacturer, 2 Toothguide 3D-Master shades need to be mixed in a 50:50 ratio to create an intermediate shade. The purpose of the study was to relate the lightness, chroma, and hue groups of the 3D-Master System with the polar coordinates of the CIELAB chromatic space, L*, C*, and h*, and to quantify the shades tabs and intermediate shades of the 3D-Master System according to color coordinates. The middle third of the facial surface of a natural maxillary central incisor was measured with an Easyshade Compact spectrophotometer (Vita Zahnfabrik) in 1361 Spanish participants aged between 16 and 89 years. Natural tooth color was recorded in the 3D-Master nomenclature and in the CIE L*, C*, and h* coordinates system. The program used for the present descriptive statistical analysis of the results was SAS 9.1.3. In the L* variable, the minimum was found at 47.0 and the maximum at 91.3. In the C* variable, the minimum was found at 5.9 and the maximum at 49.8, while for h*, the minimum was 67.5 degrees and the maximum 112.0 degrees. Despite the limitations of this study, the 3D-Master System was found to be arranged according to L*, C*, and h* coordinates in groups of lightness, chroma, and hue. The corresponding groups of lightness, chroma, and hue can be estimated on the basis of L*, C*, and h* coordinates. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Applicability of the CIELAB and CIEDE2000 Formulae for Detection of Colour Changes in Colour-Changeable Chewing Gum for Evaluating Masticatory Function

PubMed Central

Yeerken, Yesiboli; Said, Mohamed; Li, Na; Taniguchi, Hisashi

2017-01-01

Introduction Mastication is one of the essential stomatognathic functions and is impaired when mandibulectomy is performed for removal of head and neck lesions. Aim The purpose of this study was to investigate the correlation between perceived chewing ability {Masticatory Score (MS)} and objective mixing ability (∆E) in patients who had undergone marginal mandibulectomy. Materials and Methods Twenty normal dentate subjects as control group and twenty mandibulectomy patients who had undergone marginal mandibulectomy and wearing a dentomaxillary prosthesis were enrolled. Perceived chewing ability MS and objective ∆E were evaluated using a food intake questionnaire and the colour-changeable chewing gum, respectively. They were instructed to chew the gum continuously for 100 strokes on their usual side. The chewed gum was measured using the CIELAB colour space defined by a colourimeter and L, a* and b* were obtained. The change in colour of the gum after chewing was calculated using CIELAB (∆Eab) and the CIEDE2000 (∆E00) formula. The relationships of a*, ∆Eab, and ∆E00 with MS score were analyzed using the Spearman’s rank correlation coefficient. Results A correlation was found between perceived chewing ability (MS) and objective mixing ability (index of the masticatory function {∆E}) in marginal mandibulectomy patients. (∆E00 = 0.481, a* = 0.587, ∆Eab = 0.668). Conclusion Within the limitations of this study, it can be concluded that the CIEDE2000 formula for calculation of colour difference can be used to evaluate masticatory function in patients who have undergone marginal mandibulectomy. PMID:28571278

Color separation in forensic image processing using interactive differential evolution.

PubMed

Mushtaq, Harris; Rahnamayan, Shahryar; Siddiqi, Areeb

2015-01-01

Color separation is an image processing technique that has often been used in forensic applications to differentiate among variant colors and to remove unwanted image interference. This process can reveal important information such as covered text or fingerprints in forensic investigation procedures. However, several limitations prevent users from selecting the appropriate parameters pertaining to the desired and undesired colors. This study proposes the hybridization of an interactive differential evolution (IDE) and a color separation technique that no longer requires users to guess required control parameters. The IDE algorithm optimizes these parameters in an interactive manner by utilizing human visual judgment to uncover desired objects. A comprehensive experimental verification has been conducted on various sample test images, including heavily obscured texts, texts with subtle color variations, and fingerprint smudges. The advantage of IDE is apparent as it effectively optimizes the color separation parameters at a level indiscernible to the naked eyes. © 2014 American Academy of Forensic Sciences.

Use of ocean color scanner data in water quality mapping

NASA Technical Reports Server (NTRS)

Khorram, S.

1981-01-01

Remotely sensed data, in combination with in situ data, are used in assessing water quality parameters within the San Francisco Bay-Delta. The parameters include suspended solids, chlorophyll, and turbidity. Regression models are developed between each of the water quality parameter measurements and the Ocean Color Scanner (OCS) data. The models are then extended to the entire study area for mapping water quality parameters. The results include a series of color-coded maps, each pertaining to one of the water quality parameters, and the statistical analysis of the OCS data and regression models. It is found that concurrently collected OCS data and surface truth measurements are highly useful in mapping the selected water quality parameters and locating areas having relatively high biological activity. In addition, it is found to be virtually impossible, at least within this test site, to locate such areas on U-2 color and color-infrared photography.

Changes in antioxidant capacity and colour associated with the formation of β-carotene epoxides and oxidative cleavage derivatives.

PubMed

Gurak, Poliana D; Mercadante, Adriana Z; González-Miret, M L; Heredia, Francisco J; Meléndez-Martínez, Antonio J

2014-03-15

In this study HPLC-DAD-MS/MS was applied for the identification of compounds derived from (all-E)-β-carotene following epoxidation and oxidative cleavage. The consequences on the CIELAB colour parameters and antioxidant capacity (AC) were also evaluated. Five apocarotenoids, three secocarotenoids, seven Z isomers and two epoxides were detected as a result of the oxidative cleavage. Four epoxides and three Z isomers were detected as a consequence of the epoxidation reaction. Some compounds were detected for the first time as a result of oxidation reactions. Both treatments led to a marked decrease in b(∗) and Cab(∗) values, indicating that these colour parameters can be used for the rapid assessment of β-carotene oxidation. The oxidative cleavage of β-carotene resulted in increased capacity to both scavenge ABTS(+) and quench singlet oxygen. These results suggest that the study of the AC of these oxidative derivatives and their possible usefulness as food ingredients deserves further attention. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparison of the color of natural teeth measured by a colorimeter and Shade Vision System.

PubMed

Cho, Byeong-Hoon; Lim, Yong-Kyu; Lee, Yong-Keun

2007-10-01

The objectives were to measure the difference in the color and color parameters of natural teeth measured by a tristimulus colorimeter (CM, used as a reference) and Shade Vision System (SV), and to determine the influence of color parameters on the color difference between the values measured by two instruments. Color of 12 maxillary and mandibular anterior teeth was measured by CM and SV for 47 volunteers (number of teeth=564). Color parameters such as CIE L*, a* and b* values, chroma and hue angle measured by two instruments were compared. Chroma was calculated as C*ab=(a*2 = b*2)1/2, and hue angle was calculated as h degrees =arctan(b*/a*). The influence of color parameters measured by CM on the color difference (DeltaE*(ab)) between the values measured by two instruments was analyzed with multiple regression analysis (alpha=0.01). Mean DeltaE*(ab) value between the values measured by two instruments was 21.7 (+/-3.7), and the mean difference in lightness (CIE L*) and chroma was 16.2 (+/-3.9) and 13.2 (+/-3.0), respectively. Difference in hue angle was high as 132.7 (+/-53.3) degrees . Except for the hue angle, all the color parameters showed significant correlations and the coefficient of determination (r(2)) was in the range of 0.089-0.478. Based on multiple regression analysis, the standardized partial correlation coefficient (beta) of the included predictors for the color difference was -0.710 for CIE L* and -0.300 for C*(ab) (p<0.01). All the color parameters showed significant but weak correlations except for hue angle. When lightness and chroma of teeth were high, color difference between the values measured by two instruments was small. Clinical accuracy of two instruments should be investigated further.

[Influence of repeated sintering on the color of two brands of porcelain-fused-to-titanium].

PubMed

Shu, Cheng-jun; Luo, Xiao-ping; Wu, Lie

2007-08-01

To investigate the influence of repeated sintering on the color of two porcelain-fused-to-titanium, and the differences between the two porcelains. Thirty samples were prepared and sintered for 9 times. The color of samples were measured following sintering 1, 3, 5, 7, 9 times by ShadeEye NCC colorimeter according to two brands of porcelains with CIE1976L*a*b* color system, and calculated relevant chrome, chromatism and hue, and statistical analysis. When two brands of porcelains were sintered 5 times, the color parameters had no significant change and sintered continuely, the color parameters of L* and a* had obvious changes, but can't be observed by eyes. The color parameters of titanium-porcelains have no significant change after repeated sintering.

Color image encryption based on color blend and chaos permutation in the reality-preserving multiple-parameter fractional Fourier transform domain

NASA Astrophysics Data System (ADS)

Lang, Jun

2015-03-01

In this paper, we propose a novel color image encryption method by using Color Blend (CB) and Chaos Permutation (CP) operations in the reality-preserving multiple-parameter fractional Fourier transform (RPMPFRFT) domain. The original color image is first exchanged and mixed randomly from the standard red-green-blue (RGB) color space to R‧G‧B‧ color space by rotating the color cube with a random angle matrix. Then RPMPFRFT is employed for changing the pixel values of color image, three components of the scrambled RGB color space are converted by RPMPFRFT with three different transform pairs, respectively. Comparing to the complex output transform, the RPMPFRFT transform ensures that the output is real which can save storage space of image and convenient for transmission in practical applications. To further enhance the security of the encryption system, the output of the former steps is scrambled by juxtaposition of sections of the image in the reality-preserving multiple-parameter fractional Fourier domains and the alignment of sections is determined by two coupled chaotic logistic maps. The parameters in the Color Blend, Chaos Permutation and the RPMPFRFT transform are regarded as the key in the encryption algorithm. The proposed color image encryption can also be applied to encrypt three gray images by transforming the gray images into three RGB color components of a specially constructed color image. Numerical simulations are performed to demonstrate that the proposed algorithm is feasible, secure, sensitive to keys and robust to noise attack and data loss.

IMPROVED SPECTROPHOTOMETER FIBER SAMPLING SYSTEM FOR COTTON FIBER COLOR MEASUREMENTS

USDA-ARS?s Scientific Manuscript database

Cotton in the U.S. is classified for color using the Uster® High Volume Instrument (HVI), and the parameters Rd and +b are used to designate color grades for cotton fiber. However, Rd and +b are cotton-specific color parameters, and the need existed to demonstrate the relationships of Rd and +b to...

Evaluation of Staining-Dependent Colour Changes in Resin Composites Using Principal Component Analysis

PubMed Central

Manojlovic, D.; Lenhardt, L.; Milićević, B.; Antonov, M.; Miletic, V.; Dramićanin, M. D.

2015-01-01

Colour changes in Gradia Direct™ composite after immersion in tea, coffee, red wine, Coca-Cola, Colgate mouthwash, and distilled water were evaluated using principal component analysis (PCA) and the CIELAB colour coordinates. The reflection spectra of the composites were used as input data for the PCA. The output data (scores and loadings) provided information about the magnitude and origin of the surface reflection changes after exposure to the staining solutions. The reflection spectra of the stained samples generally exhibited lower reflection in the blue spectral range, which was manifested in the lower content of the blue shade for the samples. Both analyses demonstrated the high staining abilities of tea, coffee, and red wine, which produced total colour changes of 4.31, 6.61, and 6.22, respectively, according to the CIELAB analysis. PCA revealed subtle changes in the reflection spectra of composites immersed in Coca-Cola, demonstrating Coca-Cola’s ability to stain the composite to a small degree. PMID:26450008

Evaluation of Staining-Dependent Colour Changes in Resin Composites Using Principal Component Analysis.

PubMed

Manojlovic, D; Lenhardt, L; Milićević, B; Antonov, M; Miletic, V; Dramićanin, M D

2015-10-09

Colour changes in Gradia Direct™ composite after immersion in tea, coffee, red wine, Coca-Cola, Colgate mouthwash, and distilled water were evaluated using principal component analysis (PCA) and the CIELAB colour coordinates. The reflection spectra of the composites were used as input data for the PCA. The output data (scores and loadings) provided information about the magnitude and origin of the surface reflection changes after exposure to the staining solutions. The reflection spectra of the stained samples generally exhibited lower reflection in the blue spectral range, which was manifested in the lower content of the blue shade for the samples. Both analyses demonstrated the high staining abilities of tea, coffee, and red wine, which produced total colour changes of 4.31, 6.61, and 6.22, respectively, according to the CIELAB analysis. PCA revealed subtle changes in the reflection spectra of composites immersed in Coca-Cola, demonstrating Coca-Cola's ability to stain the composite to a small degree.

Effect of different high-palladium metal-ceramic alloys on the color of opaque and dentin porcelain.

PubMed

Stavridakis, Minos M; Papazoglou, Efstratios; Seghi, Robert R; Johnston, William M; Brantley, William A

2004-08-01

The color of dental porcelain depends on the type of metal substrate. Little research has been done to document the effects of different types of high-palladium alloys on the color of dental porcelain. The purpose of this in vitro study was to evaluate the effects of different high-palladium alloys on the resulting color of dentin porcelain, as well as on that of opaque porcelain after simulated dentin and glazing firing cycles. Three Pd-Cu-Ga alloys, Spartan Plus (S), Liberty (B), and Freedom Plus (F), and 5 Pd-Ga alloys, Legacy (L), IS 85 (I), Protocol (P), Legacy XT (X), and Jelenko No.1 (N), were examined. A Pd-Ag alloy, Super Star (T), was included for comparison to the high-palladium alloys, and the Au-Pd alloy, Olympia (O), served as the control. Six cast discs (16 x 1 mm) were prepared from each of the alloys. Shade B1 opaque porcelain (Vita-Omega) was applied at a final thickness of 0.1 mm. After 2 opaque porcelain firing cycles, the surfaces were airborne-particle abraded, and the specimens were divided into 2 groups. In the first group, 0.9 mm of B1 dentin porcelain was applied. The other group of specimens with only opaque porcelain underwent the same dentin porcelain and glazing firing cycles. Color differences (DeltaE) were determined with a colorimeter between the control and each experimental group, after the second opaque porcelain, second dentin porcelain, and glazing firing cycles. One-way analysis of variance and Dunnett's multiple range test were performed on the DeltaE data (alpha=.05). After the application of dentin porcelain, the 3 Pd-Cu-Ga alloys showed significantly different (P<.05) DeltaE values (S=2.3 +/- 0.5, B=1.4 +/- 0.3, and F=1.3 +/- 0.7) than the control group. After the glazing cycle of this group, the 3 Pd-Cu-Ga alloys and the Pd-Ag alloy exhibited significantly different (P<.05) DeltaE values (S=2.8 +/- 0.8, B=2.2 +/- 0.3, F=1.9 +/- 1.0, and T=1.4 +/- 0.5) than the control group. After the simulated dentin porcelain firing cycles, the specimens with only opaque porcelain exhibited significantly different (P<.05) DeltaE values (S=5.2 +/- 1.4, B=5.4 +/- 0.6, and F=3.9 +/- 0.2) than the control group. The color difference between the 3 Pd-Cu-Ga alloys with only opaque porcelain and the control group increased more after the simulated glazing cycle (S=6.6 +/- 1.5, B=6.3 +/- 0.5, and F=4.6 +/- 0.1). The observed color differences between the Pd-Ga alloys and the control group were not statistically significant at any point. The Pd-Cu-Ga alloys with only opaque porcelain, after the simulated dentin porcelain and glazing firing cycles, exhibited clinically unacceptable color differences. The application of dentin porcelain to the Pd-Cu-Ga alloys resulted in clinically acceptable color differences. The application of dentin porcelain to the Pd-Ag alloy, after the glazing firing cycle, resulted in clinically acceptable color differences (approximately 2.8 to 3.7 DeltaE CIELAB units). The Pd-Ag alloy specimens with only opaque porcelain did not exhibit significant color differences from the control group, whereas significant color differences from the control group after the dentin porcelain and glazing firing cycles were still clinically acceptable.

Automatic T1 bladder tumor detection by using wavelet analysis in cystoscopy images

NASA Astrophysics Data System (ADS)

Freitas, Nuno R.; Vieira, Pedro M.; Lima, Estevão; Lima, Carlos S.

2018-02-01

Correct classification of cystoscopy images depends on the interpreter’s experience. Bladder cancer is a common lesion that can only be confirmed by biopsying the tissue, therefore, the automatic identification of tumors plays a significant role in early stage diagnosis and its accuracy. To our best knowledge, the use of white light cystoscopy images for bladder tumor diagnosis has not been reported so far. In this paper, a texture analysis based approach is proposed for bladder tumor diagnosis presuming that tumors change in tissue texture. As is well accepted by the scientific community, texture information is more present in the medium to high frequency range which can be selected by using a discrete wavelet transform (DWT). Tumor enhancement can be improved by using automatic segmentation, since a mixing with normal tissue is avoided under ideal conditions. The segmentation module proposed in this paper takes advantage of the wavelet decomposition tree to discard poor texture information in such a way that both steps of the proposed algorithm segmentation and classification share the same focus on texture. Multilayer perceptron and a support vector machine with a stratified ten-fold cross-validation procedure were used for classification purposes by using the hue-saturation-value (HSV), red-green-blue, and CIELab color spaces. Performances of 91% in sensitivity and 92.9% in specificity were obtained regarding HSV color by using both preprocessing and classification steps based on the DWT. The proposed method can achieve good performance on identifying bladder tumor frames. These promising results open the path towards a deeper study regarding the applicability of this algorithm in computer aided diagnosis.

Study of Chromatic parameters of Line, Total, Middle graphs and Graph operators of Bipartite graph

NASA Astrophysics Data System (ADS)

Nagarathinam, R.; Parvathi, N.

2018-04-01

Chromatic parameters have been explored on the basis of graph coloring process in which a couple of adjacent nodes receives different colors. But the Grundy and b-coloring executes maximum colors under certain restrictions. In this paper, Chromatic, b-chromatic and Grundy number of some graph operators of bipartite graph has been investigat

Color superfluidity of neutral ultracold fermions in the presence of color-flip and color-orbit fields

NASA Astrophysics Data System (ADS)

Kurkcuoglu, Doga Murat; Sá de Melo, C. A. R.

2018-02-01

We describe how color superfluidity is modified in the presence of color-flip and color-orbit fields in the context of ultracold atoms and discuss connections between this problem and that of color superconductivity in quantum chromodynamics. We study the case of s -wave contact interactions between different colors and we identify several superfluid phases, with five being nodal and one being fully gapped. When our system is described in a mixed-color basis, the superfluid order parameter tensor is characterized by six independent components with explicit momentum dependence induced by color-orbit coupling. The nodal superfluid phases are topological in nature and the low-temperature phase diagram of the color-flip field versus the interaction parameter exhibits a pentacritical point, where all five nodal color superfluid phases converge. These results are in sharp contrast to the case of zero color-flip and color-orbit fields, where the system has perfect U(3) symmetry and possesses a superfluid phase that is characterized by fully gapped quasiparticle excitations with a single complex order parameter with no momentum dependence and by inert unpaired fermions representing a nonsuperfluid component. In the latter case, just a crossover between a Bardeen-Cooper-Schrieffer and a Bose-Einstein-condensation superfluid occurs. Furthermore, we analyze the order parameter tensor in a total pseudospin basis, investigate its momentum dependence in the singlet, triplet, and quintet sectors, and compare the results with the simpler case of spin-1/2 fermions in the presence of spin-flip and spin-orbit fields, where only singlet and triplet channels arise. Finally, we analyze in detail spectroscopic properties of color superfluids in the presence of color-flip and color-orbit fields, such as the quasiparticle excitation spectrum, momentum distribution, and density of states to help characterize all the encountered topological quantum phases, which can be realized in fermionic isotopes of lithium, potassium, and ytterbium atoms with three internal states trapped.

Consistency in color parameters of a commonly used shade guide.

PubMed

Tashkandi, Esam

2010-01-01

The use of shade guides to assess the color of natural teeth subjectively remains one of the most common means for dental shade assessment. Any variation in the color parameters of the different shade guides may lead to significant clinical implications. Particularly, since the communication between the clinic and the dental laboratory is based on using the shade guide designation. The purpose of this study was to investigate the consistency of the L∗a∗b∗ color parameters of a sample of a commonly used shade guide. The color parameters of a total of 100 VITAPAN Classical Vacuum shade guide (VITA Zahnfabrik, Bad Säckingen, Germany(were measured using a X-Rite ColorEye 7000A Spectrophotometer (Grand Rapids, Michigan, USA). Each shade guide consists of 16 tabs with different designations. Each shade tab was measured five times and the average values were calculated. The ΔE between the average L∗a∗b∗ value for each shade tab and the average of the 100 shade tabs of the same designation was calculated. Using the Student t-test analysis, no significant differences were found among the measured sample. There is a high consistency level in terms of color parameters of the measured VITAPAN Classical Vacuum shade guide sample tested.

Kinetics modelling of color deterioration during thermal processing of tomato paste with the use of response surface methodology

NASA Astrophysics Data System (ADS)

Ganje, Mohammad; Jafari, Seid Mahdi; Farzaneh, Vahid; Malekjani, Narges

2018-06-01

To study the kinetics of color degradation, the tomato paste was designed to be processed at three different temperatures including 60, 70 and 80 °C for 25, 50, 75 and 100 min. a/b ratio, total color difference, saturation index and hue angle were calculated with the use of three main color parameters including L (lightness), a (redness-greenness) and b (yellowness-blueness) values. Kinetics of color degradation was developed by Arrhenius equation and the alterations were modelled with the use of response surface methodology (RSM). It was detected that all of the studied responses followed a first order reaction kinetics with an exception in TCD parameter (zeroth order). TCD and a/b respectively with the highest and lowest activation energy presented the highest sensitivity to the temperature alterations. The maximum and minimum rates of alterations were observed by TCD and b parameters, respectively. It was obviously determined that all of the studied parameters (responses) were affected by the selected independent parameters.

Effect of Age on Tooth Shade, Skin Color and Skin-Tooth Color Interrelationship in Saudi Arabian Subpopulation.

PubMed

Haralur, Satheesh B

2015-08-01

Dental restoration or prosthesis in harmony with adjacent natural teeth color is indispensable part for the successful esthetic outcome. The studies indicate is existence of correlation between teeth and skin color. Teeth and skin color are changed over the aging process. The aim of the study was to explore the role of age on the tooth and skin color parameters, and to investigate the effect of ageing on teeth-skin color correlation. Total of 225 Saudi Arabian ethnic subjects was divided into three groups of 75 each. The groups were divided according to participant's age. The participant's age for Group I, Group II, and Group III was 18-29 years, 30-50 years, and above 50 years, respectively. The tooth color was identified by spectrophotometer in CIE Lab parameters. The skin color was registered with skin surface photography. The data were statistically analyzed with one-way ANOVA and correlation tests with SPSS 18 software. The Group I had the highest 'L' value of 80.26, Group III recorded the least value of 76.66. The Group III had highest yellow value 'b' at 22.72, while Group I had 19.19. The skin 'L' value was highest in the young population; the elder population had the increased red value 'a' in comparison to younger subjects. The 'L' tooth color parameter had a strong positive linear correlation with skin color in young and adult subjects. While Group III teeth showed the strong positive correlation with 'b' parameter at malar region. The elder subjects had darker and yellow teeth in comparison with younger subjects. The reddening of the skin was observed as age-related skin color change. The age had a strong influence on the teeth-skin color correlation.

Removing flicker based on sparse color correspondences in old film restoration

NASA Astrophysics Data System (ADS)

Huang, Xi; Ding, Youdong; Yu, Bing; Xia, Tianran

2018-04-01

In the long history of human civilization, archived film is an indispensable part of it, and using digital method to repair damaged film is also a mainstream trend nowadays. In this paper, we propose a sparse color correspondences based technique to remove fading flicker for old films. Our model, combined with multi frame images to establish a simple correction model, includes three key steps. Firstly, we recover sparse color correspondences in the input frames to build a matrix with many missing entries. Secondly, we present a low-rank matrix factorization approach to estimate the unknown parameters of this model. Finally, we adopt a two-step strategy that divide the estimated parameters into reference frame parameters for color recovery correction and other frame parameters for color consistency correction to remove flicker. Our method combined multi-frames takes continuity of the input sequence into account, and the experimental results show the method can remove fading flicker efficiently.

Tree Colors: Color Schemes for Tree-Structured Data.

PubMed

Tennekes, Martijn; de Jonge, Edwin

2014-12-01

We present a method to map tree structures to colors from the Hue-Chroma-Luminance color model, which is known for its well balanced perceptual properties. The Tree Colors method can be tuned with several parameters, whose effect on the resulting color schemes is discussed in detail. We provide a free and open source implementation with sensible parameter defaults. Categorical data are very common in statistical graphics, and often these categories form a classification tree. We evaluate applying Tree Colors to tree structured data with a survey on a large group of users from a national statistical institute. Our user study suggests that Tree Colors are useful, not only for improving node-link diagrams, but also for unveiling tree structure in non-hierarchical visualizations.

[Effect of five kinds of pigments on the chromaticity of dental zirconia ceramic].

PubMed

Huang, Hui; Zheng, Yuan-li; Zhang, Fu-qiang; Sun, Jing; Gao, Lian

2007-08-01

All-ceramic dental restorations should match the colour of the natural teeth in order to fulfill aesthetic demands. The goal of this study was to evaluate the colouration of zirconia ceramic by adding five kinds of pigments. The influence of the pigments concentrations on the chromaticity were also analysed. Different concentrations of five kinds of pigments were added on zirconia powder, then compacted at 200MPa using cold isostatic pressure, sintered to 1400 degrees centigrade and hold for two hours. The chromaticity of sintered bodies were measured with chroma meter. The colours achieved by the different pigments were presented in the CIELab system. The a* value increased with the added amount of Er(2)O(3), while b* value raised with the increasing amount of CeO(2) and Pr(6)O(11). However, three pigments failed to decrease L* value and the sintered body looked too bright. The sintered bodies were brown when adding Fe(2)O(3) to zirconia. Adding MnO2 could decrease the L* value of sintered bodies significantly, but had little influence on the a* and b* value. Five kinds of colorized zirconia ceramic could cover with the chromaticity range of dental ceramic which necessitate further investigation.

[Study on digitization of difference in drug color and odor of Magnoliae Officinalis Cortex before and after perspiration].

PubMed

Liu, Hong-Liang; Yan, Ren-Yi; Guo, Jian; Shao, Ai-Juan; Yang, Bin

2013-01-01

To digitalize the changes in characters of Magnoliae Officinalis Cortex after perspiration with colorimeter and electronic nose. With perspired and non-perspired Magnoliae Officinalis Cortex as objective, colorimeter and electronic nose were used to detect their color characteristic parameter and odor characteristic parameter. Finally, an identification model was established. In terms of drug color, the color characteristic parameter model was established for perspired and non-perspired Magnoliae Officinalis Cortex on the basis of L*, a*, b* color spaces. The range of 90% of reference values of perspired Magnoliae Officinalis Cortex: L* (52.22-59.42), a* (5.36-7.68), b* (22.04-27.05). The range of 90% of reference values of non-perspired Magnoliae Officinalis Cortex: L* (38.42-47.31), a* (9.63-11.85), b* (18.48-25.53). In terms of drug odor, the principal component analysis (PCA) and the partial least squares method (PLS) showed significant difference between perspired and non-perspired Magnoliae Officinalis Cortex. The difference in drug color and odor of Magnoliae Officinalis Cortex before and after perspiration can be digitalized according to color and odor characteristic parameters tested with colorimeter and electronic nose.

Relation between consumers' perceptions of color and texture of dairy desserts and instrumental measurements using a generalized procrustes analysis.

PubMed

González-Tomás, L; Costell, E

2006-12-01

Consumers' perceptions of the color and texture of 8 commercial vanilla dairy desserts were studied and related to color and rheological measurements. First, the 8 desserts were evaluated by a group of consumers by means of the Free Choice Profile. For both color and texture, a 2-dimensional solution was chosen, with dimension 1 highly related to yellow color intensity in the case of color and to thickness in the case of texture. Second, mechanical spectra, flow behavior, and instrumental color were determined. All the samples showed a time-dependent and shear-thinning flow and a mechanical spectrum typical of a weak gel. Differences were found in the flow index, in the apparent viscosity at 10 s(-1), and in the values of the storage modulus, the loss modulus, the loss angle tangent, and the complex viscosity at 1 Hz, as well as in the color parameters. Finally, sensory and instrumental relationships were investigated by a generalized Procrustes analysis. For both color and texture, a 3-dimensional solution explained a high percentage of the total variance (>80%). In these particular samples, the instrumental color parameters provided more accurate information on consumers' color perceptions than was provided by the rheological parameters of consumers' perceptions of texture.

A Real-Time Apple Grading System Using Multicolor Space

PubMed Central

2014-01-01

This study was focused on the multicolor space which provides a better specification of the color and size of the apple in an image. In the study, a real-time machine vision system classifying apples into four categories with respect to color and size was designed. In the analysis, different color spaces were used. As a result, 97% identification success for the red fields of the apple was obtained depending on the values of the parameter “a” of CIE L*a*b*color space. Similarly, 94% identification success for the yellow fields was obtained depending on the values of the parameter y of CIE XYZ color space. With the designed system, three kinds of apples (Golden, Starking, and Jonagold) were investigated by classifying them into four groups with respect to two parameters, color and size. Finally, 99% success rate was achieved in the analyses conducted for 595 apples. PMID:24574880

A new qualitative pattern classification of shear wave elastograghy for solid breast mass evaluation.

PubMed

Cong, Rui; Li, Jing; Guo, Song

2017-02-01

To examine the efficacy of qualitative shear wave elastography (SWE) in the classification and evaluation of solid breast masses, and to compare this method with conventional ultrasonograghy (US), quantitative SWE parameters and qualitative SWE classification proposed before. From April 2015 to March 2016, 314 consecutive females with 325 breast masses who decided to undergo core needle biopsy and/or surgical biopsy were enrolled. Conventional US and SWE were previously performed in all enrolled subjects. Each mass was classified by two different qualitative classifications. One was established in our study, herein named the Qual1. Qual1 could classify the SWE images into five color patterns by the visual evaluations: Color pattern 1 (homogeneous pattern); Color pattern 2 (comparative homogeneous pattern); Color pattern 3 (irregularly heterogeneous pattern); Color pattern 4 (intralesional echo pattern); and Color pattern 5 (the stiff rim sign pattern). The second qualitative classification was named Qual2 here, and included a four-color overlay pattern classification (Tozaki and Fukuma, Acta Radiologica, 2011). The Breast Imaging Reporting and Data System (BI-RADS) assessment and quantitative SWE parameters were recorded. Diagnostic performances of conventional US, SWE parameters, and combinations of US and SWE parameters were compared. With pathological results as the gold standard, of the 325 examined breast masses, 139 (42.77%) samples were malignant and 186 (57.23%) were benign. The Qual1 showed a higher Az value than the Qual2 and quantitative SWE parameters (all P<0.05). When applying Qual1=Color pattern 1 for downgrading and Qual1=Color pattern 5 for upgrading the BI-RADS categories, we obtained the highest Az value (0.951), and achieved a significantly higher specificity (86.56%, P=0.002) than that of the US (81.18%) with the same sensitivity (94.96%). The qualitative classification proposed in this study may be representative of SWE parameters and has potential to be relevant assistance in breast mass diagnoses. Copyright © 2016. Published by Elsevier B.V.

Impact of Gastric Acid Induced Surface Changes on Mechanical Behavior and Optical Characteristics of Dental Ceramics.

PubMed

Kulkarni, Aditi; Rothrock, James; Thompson, Jeffery

2018-01-14

To test the impact of exposure to artificial gastric acid combined with toothbrush abrasion on the properties of dental ceramics. Earlier research has indicated that immersion in artificial gastric acid has caused increased surface roughness of dental ceramics; however, the combined effects of acid immersion and toothbrush abrasion and the impact of increased surface roughness on mechanical strength and optical properties have not been studied. Three commercially available ceramics were chosen for this study: feldspathic porcelain, lithium disilicate glass-ceramic, and monolithic zirconium oxide. The specimens (10 × 1 mm discs) were cut, thermally treated as required, and polished. Each material was divided into four groups (n = 8 per group): control (no exposure), acid only, brush only, acid + brush. The specimens were immersed in artificial gastric acid (50 ml of 0.2% [w/v] sodium chloride in 0.7% [v/v] hydrochloric acid mixed with 0.16 g of pepsin powder, pH = 2) for 2 minutes and rinsed with deionized water for 2 minutes. The procedure was repeated 6 times/day × 9 days, and specimens were stored in deionized water at 37°C. Toothbrush abrasion was performed using an ISO/ADA design brushing machine for 100 cycles/day × 9 days. The acid + brush group received both treatments. Specimens were examined under SEM and an optical microscope for morphological changes. Color and translucency were measured using spectrophotometer CIELAB coordinates (L*, a*, b*). Surface gloss was measured using a gloss meter. Surface roughness was measured using a stylus profilometer. Biaxial flexural strength was measured using a mechanical testing machine. The data were analyzed by one-way ANOVA followed by Tukey's HSD post hoc test (p < 0.05). Statistically significant changes were found for color, gloss, and surface roughness for porcelain and e.max specimens. No statistically significant changes were found for any properties of zirconia specimens. The acid treatment affected the surface roughness, color, and gloss of porcelain and e.max ceramics. The changes in translucency and mechanical strength for all materials were not statistically significant. Zirconia ceramic showed resistance to all treatments. © 2018 by the American College of Prosthodontists.

Clinical utility of capsule endoscopy with flexible spectral imaging color enhancement for diagnosis of small bowel lesions

PubMed Central

Sato, Yasushi; Sagawa, Tamotsu; Hirakawa, Masahiro; Ohnuma, Hiroyuki; Osuga, Takahiro; Okagawa, Yutaka; Tamura, Fumito; Horiguchi, Hiroto; Takada, Kohichi; Hayashi, Tsuyoshi; Sato, Tsutomu; Miyanishi, Koji; Takimoto, Rishu; Kobune, Masayoshi; Kato, Junji

2014-01-01

Background and study aims: The clinical utility of computed virtual chromoendoscopy with flexible spectral imaging color enhancement (FICE) in capsule endoscopy (CE) remains controversial. To clarify the clinical utility of FICE-enhanced CE in evaluating small bowel lesions, we quantitatively assessed white light (WL), FICE, and blue mode (BM) images and examined the sensitivity of these 3 imaging modes of small-bowel lesions from patients who underwent CE. Methods: The CIELAB color difference (∆E) and visual analogue scales (VAS) were measured in 261 CE images (3 different lesion categories) using WL and FICE set 1, 2, and 3, and BM images, respectively. Three endoscopists reviewed CE videos with WL, 3 FICE mode settings, and BM, and compared the sensitivity and detectability for small intestinal diseases from 50 patients who underwent CE. Results: In the assessment of visibility in the 152 vascular lesion images, the ∆E and VAS of FICE set 1, 2, and BM images were significantly higher than that of WL images. In 88 erosion/ulceration images, the ∆E and VAS of FICE set 1 and 2 images were significantly higher than that of WL images. In 21 tumor images, there were no significant differences in ∆E among these modalities. When analyzed on a per-patient basis, FICE settings 1 and 2 had the highest sensitivity (100 %) and specificity (97.3 – 100 %) for vascular lesions. As for erosive/ulcerative lesions, FICE setting 2 had the highest sensitivity (100 %) and specificity (97.2 %). For tumors or polyps, WL had the highest sensitivity (90.9 %) and specificity (87.1 %). In per-lesion analysis, FICE settings 1 and 2 showed significantly superior detection ability over WL for vascular lesions. In the detection of erosive/ulcerative lesions, FICE setting 2 was significantly superior to WL. In tumor images, there was no significant improvement with any of the settings relative to WL images. Conclusions: FICE is most useful for improving CE image quality and detection in cases of angioectasia and erosion/ulceration of the small intestine. PMID:26135265

Reliability and validity of tongue color analysis in the prediction of symptom patterns in terms of East Asian Medicine.

PubMed

Park, Young-Jae; Lee, Jin-Moo; Yoo, Seung-Yeon; Park, Young-Bae

2016-04-01

To examine whether color parameters of tongue inspection (TI) using a digital camera was reliable and valid, and to examine which color parameters serve as predictors of symptom patterns in terms of East Asian medicine (EAM). Two hundred female subjects' tongue substances were photographed by a mega-pixel digital camera. Together with the photographs, the subjects were asked to complete Yin deficiency, Phlegm pattern, and Cold-Heat pattern questionnaires. Using three sets of digital imaging software, each digital image was exposure- and white balance-corrected, and finally L* (luminance), a* (red-green balance), and b* (yellow-blue balance) values of the tongues were calculated. To examine intra- and inter-rater reliabilities and criterion validity of the color analysis method, three raters were asked to calculate color parameters for 20 digital image samples. Finally, four hierarchical regression models were formed. Color parameters showed good or excellent reliability (0.627-0.887 for intra-class correlation coefficients) and significant criterion validity (0.523-0.718 for Spearman's correlation). In the hierarchical regression models, age was a significant predictor of Yin deficiency (β = 0.192), and b* value of the tip of the tongue was a determinant predictor of Yin deficiency, Phlegm, and Heat patterns (β = - 0.212, - 0.172, and - 0.163). Luminance (L*) was predictive of Yin deficiency (β = -0.172) and Cold (β = 0.173) pattern. Our results suggest that color analysis of the tongue using the L*a*b* system is reliable and valid, and that color parameters partially serve as symptom pattern predictors in EAM practice.

Effect of sampling location on L* values and pH measurements and their relationship in broiler breast fillets

USDA-ARS?s Scientific Manuscript database

Lightness (CIELAB L*) and pH values are the most widely measured quality indicators for broiler breast fillets (pectoralis major). Measurement of L* values with a spectrophotometer can be done through Specular Component Included (SCI) or Specular Component Excluded (SCE) modes. The intra-fillet loca...

Biomimetic plasmonic color generated by the single-layer coaxial honeycomb nanostructure arrays

NASA Astrophysics Data System (ADS)

Zhao, Jiancun; Gao, Bo; Li, Haoyong; Yu, Xiaochang; Yang, Xiaoming; Yu, Yiting

2017-07-01

We proposed a periodic coaxial honeycomb nanostructure array patterned in a silver film to realize the plasmonic structural color, which was inspired from natural honeybee hives. The spectral characteristics of the structure with variant geometrical parameters are investigated by employing a finite-difference time-domain method, and the corresponding colors are thus derived by calculating XYZ tristimulus values corresponding with the transmission spectra. The study demonstrates that the suggested structure with only a single layer has high transmission, narrow full-width at half-maximum, and wide color tunability by changing geometrical parameters. Therefore, the plasmonic colors realized possess a high color brightness, saturation, as well as a wide color gamut. In addition, the strong polarization independence makes it more attractive for practical applications. These results indicate that the recommended color-generating plasmonic structure has various potential applications in highly integrated optoelectronic devices, such as color filters and high-definition displays.

A color-communication scheme for digital imagery

USGS Publications Warehouse

Acosta, Alex

1987-01-01

Color pictures generated from digital images are frequently used by geologists, foresters, range managers, and others. These color products are preferred over black and white pictures because the human eye is more sensitive to color differences than to various shades of gray. Color discrimination is a function of perception, and therefore colors in these color composites are generally described subjectively, which can lead to ambiguous color communication. Numerous color-coordinate systems are available that quantitively relate digital triplets representing amounts of red, free, and blue to the parameters of hue, saturation, and intensity perceived by the eye. Most of these systems implement a complex transformation of the primary colors to a color space that is hard to visualize, thus making it difficult to relate digital triplets to perception parameters. This paper presents a color-communcation scheme that relates colors on a color triangle to corresponding values of "hue" (H), "saturation" (S), and chromaticity coordinates (x,y,z). The scheme simplifies the relation between red, green, and blue (RGB) digital triplets and the color generated by these triplets. Some examples of the use of the color-communication scheme in digital image processing are presented.

Evaluation of parameters of color profile models of LCD and LED screens

NASA Astrophysics Data System (ADS)

Zharinov, I. O.; Zharinov, O. O.

2017-12-01

The purpose of the research relates to the problem of parametric identification of the color profile model of LCD (liquid crystal display) and LED (light emitting diode) screens. The color profile model of a screen is based on the Grassmann’s Law of additive color mixture. Mathematically the problem is to evaluate unknown parameters (numerical coefficients) of the matrix transformation between different color spaces. Several methods of evaluation of these screen profile coefficients were developed. These methods are based either on processing of some colorimetric measurements or on processing of technical documentation data.

Application of a central composite design to evaluate the influence of colouring agents in lipstick formulation.

PubMed

Zibetti, F M; Cardoso, A C A; Desmarais, G C; de Almeida, K B; do Nascimento, L M; Rolim, L F; Rocha, M S; Duarte, N G D; Azevedo, P H R A; Araújo, J L; Mourão, S C; Falcão, D Q

2016-10-01

The aim of this study was to evaluate by central composite design the influence of colouring agents in lipstick colour, expressed by L*, a*, b* parameters (CIELab system) where L* indicates lightness, and a* and b* are the chromaticity coordinates. The a* indicates colour direction from red to green and b* from yellow to blue. Lipsticks were formulated as described by (Recent Adv. Prosp. Potent Med. Plants, 2009 and 39). The combined effect of three variables (dye, pigment and opacifier) was evaluated by different formulations in a central composite design. Colour parameters (L*, a*, b*) were analysed by reflectance spectrophotometry. Lipsticks were characterized by visual analyses and melting point. All formulations were integrate and homogeneous. The pigments and dye do not influence in colour transfer neither in melting point of lipsticks. On the other hand, results indicated that variables studied show influence only in parameter b*, whereas for L* and a* values there was no significant difference (P < 0.05). It was possible to verify that only the colour parameter b* was influenced by the variation in colouring agent's concentrations in lipstick formulation, leading to the production of the colour ranging between violet and light red. Such results are useful for developing new lipstick formulations to obtain the desired colour in the final product. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Investigation of two methods to quantify noise in digital images based on the perception of the human eye

NASA Astrophysics Data System (ADS)

Kleinmann, Johanna; Wueller, Dietmar

2007-01-01

Since the signal to noise measuring method as standardized in the normative part of ISO 15739:2002(E)1 does not quantify noise in a way that matches the perception of the human eye, two alternative methods have been investigated which may be appropriate to quantify the noise perception in a physiological manner: - the model of visual noise measurement proposed by Hung et al2 (as described in the informative annex of ISO 15739:20021) which tries to simulate the process of human vision by using the opponent space and contrast sensitivity functions and uses the CIEL*u*v*1976 colour space for the determination of a so called visual noise value. - The S-CIELab model and CIEDE2000 colour difference proposed by Fairchild et al 3 which simulates human vision approximately the same way as Hung et al2 but uses an image comparison afterwards based on CIEDE2000. With a psychophysical experiment based on just noticeable difference (JND), threshold images could be defined, with which the two approaches mentioned above were tested. The assumption is that if the method is valid, the different threshold images should get the same 'noise value'. The visual noise measurement model results in similar visual noise values for all the threshold images. The method is reliable to quantify at least the JND for noise in uniform areas of digital images. While the visual noise measurement model can only evaluate uniform colour patches in images, the S-CIELab model can be used on images with spatial content as well. The S-CIELab model also results in similar colour difference values for the set of threshold images, but with some limitations: for images which contain spatial structures besides the noise, the colour difference varies depending on the contrast of the spatial content.

Color identification and fuzzy reasoning based monitoring and controlling of fermentation process of branched chain amino acid

NASA Astrophysics Data System (ADS)

Ma, Lei; Wang, Yizhong; Xu, Qingyang; Huang, Huafang; Zhang, Rui; Chen, Ning

2009-11-01

The main production method of branched chain amino acid (BCAA) is microbial fermentation. In this paper, to monitor and to control the fermentation process of BCAA, especially its logarithmic phase, parameters such as the color of fermentation broth, culture temperature, pH, revolution, dissolved oxygen, airflow rate, pressure, optical density, and residual glucose, are measured and/or controlled and/or adjusted. The color of fermentation broth is measured using the HIS color model and a BP neural network. The network's input is the histograms of hue H and saturation S, and output is the color description. Fermentation process parameters are adjusted using fuzzy reasoning, which is performed by inference rules. According to the practical situation of BCAA fermentation process, all parameters are divided into four grades, and different fuzzy rules are established.

Influence of combined pretreatments on color parameters during convective drying of Mirabelle plum ( Prunus domestica subsp. syriaca)

NASA Astrophysics Data System (ADS)

Dehghannya, Jalal; Gorbani, Rasoul; Ghanbarzadeh, Babak

2017-07-01

Discoloration and browning are caused primarily by various reactions, including Maillard condensation of hexoses and amino components, phenol polymerization and pigment destruction. Convective drying can be combined with various pretreatments to help reduce undesired color changes and improve color parameters of dried products. In this study, effects of ultrasound-assisted osmotic dehydration as a pretreatment before convective drying on color parameters of Mirabelle plum were investigated. Variations of L* (lightness), a* (redness/greenness), b* (yellowness/blueness), total color change (ΔE), chroma, hue angle and browning index values were presented versus drying time during convective drying of control and pretreated Mirabelle plums as influenced by ultrasonication time, osmotic solution concentration and immersion time in osmotic solution. Samples pretreated with ultrasound for 30 min and osmotic solution concentration of 70% had a more desirable color among all other pretreated samples, with the closest L*, a* and b* values to the fresh one, showing that ultrasound and osmotic dehydration are beneficial to the color of final products after drying.

Development and Performance Assessment of White LED Dimmer

NASA Astrophysics Data System (ADS)

Maiti, Pradip Kr.; Roy, Biswanath

2017-10-01

A microcontroller based electronic dimmer is developed using pulse width modulation technique. This dimmer is controllable by infra-red remote within a distance of 4 m and can be electrically connected between LED module and its driver. The performance of a developed LED dimmer is assessed on basis of variation of the photometric parameters of commercially available warm white and cool white LED luminaire used in indoor lighting applications. Four equally spaced dimming levels are considered to measure luminous efficacy, spectral power distribution, CIE 1931 chromaticity coordinates, CIE 1976 CIELUV color difference, correlated color temperature, general color rendering index and one specific color rendering index for saturated red color sample. Variations of above parameters are found out with reference to the values measured at rated voltage without the developed dimmer. Analysis of experimentally measured data shows that the developed LED dimmer is capable to vary light output of the WLED luminaire within a range of 25-100% without appreciable variation of its photometric and color parameters. The only exception is observed for the luminous efficacy parameter where it shows about 17 and 14.7% reduction for warm white and cool white LED luminaire at 25% dimming level.

Sequential weighted Wiener estimation for extraction of key tissue parameters in color imaging: a phantom study

NASA Astrophysics Data System (ADS)

Chen, Shuo; Lin, Xiaoqian; Zhu, Caigang; Liu, Quan

2014-12-01

Key tissue parameters, e.g., total hemoglobin concentration and tissue oxygenation, are important biomarkers in clinical diagnosis for various diseases. Although point measurement techniques based on diffuse reflectance spectroscopy can accurately recover these tissue parameters, they are not suitable for the examination of a large tissue region due to slow data acquisition. The previous imaging studies have shown that hemoglobin concentration and oxygenation can be estimated from color measurements with the assumption of known scattering properties, which is impractical in clinical applications. To overcome this limitation and speed-up image processing, we propose a method of sequential weighted Wiener estimation (WE) to quickly extract key tissue parameters, including total hemoglobin concentration (CtHb), hemoglobin oxygenation (StO2), scatterer density (α), and scattering power (β), from wide-band color measurements. This method takes advantage of the fact that each parameter is sensitive to the color measurements in a different way and attempts to maximize the contribution of those color measurements likely to generate correct results in WE. The method was evaluated on skin phantoms with varying CtHb, StO2, and scattering properties. The results demonstrate excellent agreement between the estimated tissue parameters and the corresponding reference values. Compared with traditional WE, the sequential weighted WE shows significant improvement in the estimation accuracy. This method could be used to monitor tissue parameters in an imaging setup in real time.

Influence of surface layer removal of shade guide tabs on the measured color by spectrophotometer and spectroradiometer.

PubMed

Kim, Jin-Cheol; Yu, Bin; Lee, Yong-Keun

2008-12-01

To determine the changes in color parameters of Vitapan 3D-Master shade guide tabs by a spectrophotometer (SP) or a spectroradiometer (SR), and by the removal of the surface layer of the tabs that was performed to make a flat measuring surface for the SP color measurement. Color of the shade tabs was measured before and after removing the surface layer of the tabs using SP and SR. Correlations between the color parameters between the original (OR) and the surface layer removed (RM) tabs and between the SP and the SR measurements were determined (alpha=0.05). Based on SP, the lightness, chroma, CIE a* and b* values measured after the surface layer removal were higher than those of the original tabs except a few cases. Based on SR, the chroma and CIE a* and b* values measured after surface layer removal were higher than those of the original tabs except a few cases; however, in case of the lightness, the changes varied by the shade designation. Type of instrument influenced the changes in color parameters based on paired t-test (p<0.05). The color parameters of the OR and RM tabs showed correlations based on both SP and SR measurements (r=0.952-0.997 and p<0.01); however, color difference between the SP-RM and SR-OR tabs was in the range of 18.1-27.0 DeltaE(ab)(*) units (mean: 23.3+/-2.2). When the color of tooth-shaped objects is measured with a spectrophotometer or a spectroradiometer, measurement protocols should be specified because color difference by the surface layer removal and the instrument was high.

Effects of intrinsic aging and photodamage on skin dyspigmentation: an explorative study

NASA Astrophysics Data System (ADS)

Dobos, Gabor; Trojahn, Carina; D'Alessandro, Brian; Patwardhan, Sachin; Canfield, Douglas; Blume-Peytavi, Ulrike; Kottner, Jan

2016-06-01

Photoaging is associated with increasing pigmentary heterogeneity and darkening of skin color. However, little is known about age-related changes in skin pigmentation on sun-protected areas. The aim of this explorative study was to measure skin color and dyspigmentation using image processing and to evaluate the reliability of these parameters. Twenty-four volunteers of three age-groups were included in this explorative study. Measurements were conducted at sun-exposed and sun-protected areas. Overall skin-color estimates were similar among age groups. The hyper- and hypopigmentation indices differed significantly by age groups and their correlations with age ranged between 0.61 and 0.74. Dorsal forearm skin differed from the other investigational areas (p<0.001). We observed an increase in dyspigmentation at all skin areas, including sun-protected skin areas, already in young adulthood. Associations between age and dyspigmentation estimates were higher compared to color parameters. All color and dyspigmentation estimates showed high reliability. Dyspigmentation parameters seem to be better biomarkers for UV damage than the overall color measurements.

HVI Colorimeter and Color Spectrophotometer Relationships and Their Impacts on Developing "Traceable" Cotton Color Standards

USDA-ARS?s Scientific Manuscript database

Color measurements of cotton fiber and cotton textile products are important quality parameters. The Uster® High Volume Instrument (HVI) is an instrument used globally to classify cotton quality, including cotton color. Cotton color by HVI is based on two cotton-specific color parameters—Rd (diffuse...

Caucasian facial L* shifts may communicate anti-ageing efficacy.

PubMed

Zedayko, T; Azriel, M; Kollias, N

2011-10-01

An ageing study was conducted to capture skin colour parameters in the CIELab system from Caucasians of both genders and all available adult ages. This study produced a linear correlation between L* and age for a Caucasian population between 20 and 59 years of age as follows: (L* value) = -0.13 × (Age in years) + 63.01. Previous studies have addressed age-related changes in skin colour. This work presents a novel consumer correlated quantitative linear model of skin brightness by which to communicate age-related changes. Two product assessment studies are also presented here, demonstrating the ability of anti-ageing products to deliver on objective and subjective improvements in skin brightness. It was determined to be possible to use the fundamental Caucasian L*-age correlation to describe product benefits in a novel quantitative and consumer-relevant fashion, through the depiction of a 'years back' calculation. © 2011 Johnson & Johnson Consumer Products Company. ICS © 2011 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Colour and carotenoid changes of pasteurised orange juice during storage.

PubMed

Wibowo, Scheling; Vervoort, Liesbeth; Tomic, Jovana; Santiago, Jihan Santanina; Lemmens, Lien; Panozzo, Agnese; Grauwet, Tara; Hendrickx, Marc; Van Loey, Ann

2015-03-15

The correlation of carotenoid changes with colour degradation of pasteurised single strength orange juice was investigated at 20, 28, 35 and 42°C for a total of 32 weeks of storage. Changes in colour were assessed using the CIELAB system and were kinetically described by a zero-order model. L(∗), a(∗), b(∗), ΔE(∗), Cab(∗) and hab were significantly changed during storage (p<0.05). Activation energies for all colour parameters were 64-73 kJ mol(-1). Several carotenoids showed important changes and appeared to have different susceptibilities to storage. A decrease of β-cryptoxanthin was observed at higher temperatures, whereas antheraxanthin started to decrease at lower temperatures. Depending on the time and temperature, changes in carotenoids could be due to isomerisation reactions, which may lead to a perceptible colour change. Although the contribution of carotenoids was recognised to some extent, other reactions seem of major importance for colour degradation of orange juice during storage. Copyright © 2014 Elsevier Ltd. All rights reserved.

UV light impact on ellagitannins and wood surface colour of European oak ( Quercus petraea and Quercus robur)

NASA Astrophysics Data System (ADS)

Zahri, S.; Belloncle, C.; Charrier, F.; Pardon, P.; Quideau, S.; Charrier, B.

2007-03-01

Two European oak species ( Q. petraea and Q. robur) have a high content of phenols which may participate in the alteration of colour upon UV irradiation. To study the photodegradation process of oak surfaces, the two oak species extractives, vescalagin, castalagin, ellagic acid and gallic acid were analysed quantitatively by HPLC before and after UV irradiation. Irradiation time was altered between 3, 24, 72, 96, 120, 144, 192 and 216 h. In parallel, any colour changes of Oak wood surface was followed after 120 h of UV-irradiation by measuring CIELAB parameters (DL*, Da*, Db* and DE*). We observed that 60% of total phenol content of extractives decreased after the maximal exposure time. Our findings also showed that castalagin and gallic acid were destroyed after 216 h and vescalagin and ellagic acid after 72 h. This study proves the photosenibility of oakwood extractives which, supplementary to lignin degradation, would strongly result in the discolouration of oak heartwood.

Neural networks applied to discriminate botanical origin of honeys.

PubMed

Anjos, Ofélia; Iglesias, Carla; Peres, Fátima; Martínez, Javier; García, Ángela; Taboada, Javier

2015-05-15

The aim of this work is develop a tool based on neural networks to predict the botanical origin of honeys using physical and chemical parameters. The managed database consists of 49 honey samples of 2 different classes: monofloral (almond, holm oak, sweet chestnut, eucalyptus, orange, rosemary, lavender, strawberry trees, thyme, heather, sunflower) and multifloral. The moisture content, electrical conductivity, water activity, ashes content, pH, free acidity, colorimetric coordinates in CIELAB space (L(∗), a(∗), b(∗)) and total phenols content of the honey samples were evaluated. Those properties were considered as input variables of the predictive model. The neural network is optimised through several tests with different numbers of neurons in the hidden layer and also with different input variables. The reduced error rates (5%) allow us to conclude that the botanical origin of honey can be reliably and quickly known from the colorimetric information and the electrical conductivity of honey. Copyright © 2014 Elsevier Ltd. All rights reserved.

Propagation characteristics of two-color laser pulses in homogeneous plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hemlata,; Saroch, Akanksha; Jha, Pallavi

2015-11-15

An analytical and numerical study of the evolution of two-color, sinusoidal laser pulses in cold, underdense, and homogeneous plasma has been presented. The wave equations for the radiation fields driven by linear as well as nonlinear contributions due to the two-color laser pulses have been set up. A variational technique is used to obtain the simultaneous equations describing the evolution of the laser spot size, pulse length, and chirp parameter. Numerical methods are used to graphically analyze the simultaneous evolution of these parameters due to the combined effect of the two-color laser pulses. Further, the pulse parameters are compared withmore » those obtained for a single laser pulse. Significant focusing, compression, and enhanced positive chirp is obtained due to the combined effect of simultaneously propagating two-color pulses as compared to a single pulse propagating in plasma.« less

The Visi-Chroma VC-100: a new imaging colorimeter for dermatocosmetic research.

PubMed

Barel, A O; Clarys, P; Alewaeters, K; Duez, C; Hubinon, J L; Mommaerts, M

2001-02-01

It was the aim of this study to carry out a comparative evaluation in vitro on standardized color charts and in vivo on healthy subjects using the Visi-Chroma VC-100, a new imaging tristimulus colorimeter and the Minolta Chromameter CR-200 as a reference instrument. The Visi-Chroma combines tristimulus color analysis with full color visualization of the skin area measured. The technical performances of both instruments were compared with the purpose of validating the use of this new imaging colorimeter in dermatocosmetic research. In vitro L*a*b* color parameters were taken with both instruments on standardized color charts (Macbeth and RAL charts) in order to evaluate accuracy, sensitivity range and repeatability. These measurements were completed by in vivo studies on different sites of human skin and studies of color changes induced by topical chemical agents on forearm skin. The accuracy, sensitivity range and repeatability of measurements of selected distances and surfaces in the measuring zone considered and specific color determinations of specific skin zones were also determined. The technical performance of this imaging colorimeter was rather good, with low coefficients of variation for repeatability of in vitro and vivo color measurements. High positive correlations were established in vitro and in vivo over a wide range of color measurements. The imaging colorimeter was able to measure the L*a*b* color parameters of specific chosen parts of the skin area considered and to measure accurately selected distances and surfaces in the same skin site considered. These comparative measurements show that both instruments have very similar technical performances and that high levels of correlation were obtained in vitro and in vivo using the L*a*b* color parameters. In addition, the Visi-Chroma presents the following improvements: 1) direct visualization and recording of the skin area considered with concomitant color measurements; 2) determination of the specific color parameters of skin areas chosen in the total measuring area; and 3) accurate determination of selected distances and surfaces in the same skin areas chosen.

Lipid oxidation and color changes of goose meat stored under vacuum and modified atmosphere conditions.

PubMed

Orkusz, A; Haraf, G; Okruszek, A; Werenska-Sudnik, M

2017-03-01

The objective of the work was to investigate the color and lipid oxidation changes of goose breast meat packaged in vacuum and modified atmosphere (MA) conditions consisting of 80% O2, 20% CO2, and stored in refrigerated conditions at 4°C. Color stability was monitored by determining total heme pigments concentration; relative concentration of myoglobin, oxymyoglobin, and metmyoglobin; parameters of color L*, a*, b*, and sensory evaluation of the surface color. Lipid stability was measured by determining thiobarbituric acid reactive substances (TBARS). The samples were examined in 24 h after slaughter (unpacked muscles) and on d 4, 7, 9, 11 of storage (muscles packed in vacuum and in MA). Through the time of storage, samples packed in MA had higher TBARS values in comparison to the meat packed in vacuum. For samples packed in two types of atmospheres, the total pigments concentration decreased gradually within 11 d of storage. It was observed that relative metmyoglobin concentration increased whereas relative oxymyoglobin concentration decreased in total heme pigments in the MA stored muscle. The relative concentration of all three myoglobin forms sample packed in vacuum remained unchanged. The color parameters (L*, a*, b*) did not change for 11 d of storage for the vacuum packed meat. The value of the color parameter a* decreased and the value of the color parameters L* and b* increased in the samples packaged in MA. The data prove that if you store goose meat in MA (consisting of 80% O2, 20% CO2) or vacuum, the unchanged surface color is preserved for 9 and 11 day, respectively.Vacuum appears to be a better method as regards the maintaining of lipid stability in goose meat. © 2016 Poultry Science Association Inc.

Image analysis and green tea color change kinetics during thin-layer drying.

PubMed

Shahabi, Mohammad; Rafiee, Shahin; Mohtasebi, Seyed Saeid; Hosseinpour, Soleiman

2014-09-01

This study was conducted to investigate the effect of air temperature and air flow velocity on kinetics of color parameter changes during hot-air drying of green tea, to obtain the best model for hot-air drying of green tea, to apply a computer vision system and to study the color changes during drying. In the proposed computer vision system system, at first RGB values of the images were converted into XYZ values and then to Commission International d'Eclairage L*a*b* color coordinates. The obtained color parameters of L*, a* and b* were calibrated with Hunter-Lab colorimeter. These values were also used for calculation of the color difference, chroma, hue angle and browning index. The values of L* and b* decreased, while the values of a* and color difference (ΔE*ab ) increased during hot-air drying. Drying data were fitted to three kinetic models. Zero, first-order and fractional conversion models were utilized to describe the color changes of green tea. The suitability of fitness was determined using the coefficient of determination (R (2)) and root-mean-square error. Results showed that the fraction conversion model had more acceptable fitness than the other two models in most of color parameters. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Measuring Two Key Parameters of H3 Color Centers in Diamond

NASA Technical Reports Server (NTRS)

Roberts, W. Thomas

2005-01-01

A method of measuring two key parameters of H3 color centers in diamond has been created as part of a continuing effort to develop tunable, continuous-wave, visible lasers that would utilize diamond as the lasing medium. (An H3 color center in a diamond crystal lattice comprises two nitrogen atoms substituted for two carbon atoms bonded to a third carbon atom. H3 color centers can be induced artificially; they also occur naturally. If present in sufficient density, they impart a yellow hue.) The method may also be applicable to the corresponding parameters of other candidate lasing media. One of the parameters is the number density of color centers, which is needed for designing an efficient laser. The other parameter is an optical-absorption cross section, which, as explained below, is needed for determining the number density. The present method represents an improvement over prior methods in which optical-absorption measurements have been used to determine absorption cross sections or number densities. Heretofore, in order to determine a number density from such measurements, it has been necessary to know the applicable absorption cross section; alternatively, to determine the absorption cross section from such measurements, it has been necessary to know the number density. If, as in this case, both the number density and the absorption cross section are initially unknown, then it is impossible to determine either parameter in the absence of additional information.

New color-magnetic defects in dense quark matter

NASA Astrophysics Data System (ADS)

Haber, Alexander; Schmitt, Andreas

2018-06-01

Color-flavor locked (CFL) quark matter expels color-magnetic fields due to the Meissner effect. One of these fields carries an admixture of the ordinary abelian magnetic field and therefore flux tubes may form if CFL matter is exposed to a magnetic field, possibly in the interior of neutron stars or in quark stars. We employ a Ginzburg–Landau approach for three massless quark flavors, which takes into account the multi-component nature of color superconductivity. Based on the weak-coupling expressions for the Ginzburg–Landau parameters, we identify the regime where CFL is a type-II color superconductor and compute the radial profiles of different color-magnetic flux tubes. Among the configurations without baryon circulation we find a new solution that is energetically preferred over the flux tubes previously discussed in the literature in the parameter regime relevant for compact stars. Within the same setup, we also find a new defect in the 2SC phase, namely magnetic domain walls, which emerge naturally from the previously studied flux tubes if a more general ansatz for the order parameter is used. Color-magnetic defects in the interior of compact stars allow for sustained deformations of the star, potentially strong enough to produce detectable gravitational waves.

Impact of demographic, behavioral, and dental care utilization parameters on tooth color and personal satisfaction.

PubMed

Odioso, L L; Gibb, R D; Gerlach, R W

2000-01-01

A cross-sectional survey across broad age ranges was conducted to evaluate demographic, behavioral, and treatment parameters that impact tooth color and its perception. The sample included 180 US adults and teenagers, with a comparable representation of males and females in 6 different age strata, ranging from 13 to 64 years. Tooth color (L*a*b*) was measured on the maxillary central incisors using a spectrophotometer, and first-person satisfaction with tooth color was assessed using a five-point qualitative scale. Demographic, behavioral, and oral care parameters were modeled using multiple regression analysis. After adjusting for other explanatory variables, age, gender, coffee/tea consumption, and dental care all significantly affected yellowing (b*) and brightness (L*). Dental-visit frequency was the only factor that significantly predicted self-satisfaction with tooth color, explaining just 3% of the overall variability. First-person dissatisfaction with tooth color was common and found in most demographic and behavioral cohorts. Although age contributed to objectively measured tooth discoloration, personal satisfaction with tooth color was age-independent. These results suggest that the need or demand for esthetic dentistry may be broad-based and transcend stereotypical perceptions.

Different parameters support generalization and discrimination learning in Drosophila at the flight simulator.

PubMed

Brembs, Björn; Hempel de Ibarra, Natalie

2006-01-01

We have used a genetically tractable model system, the fruit fly Drosophila melanogaster to study the interdependence between sensory processing and associative processing on learning performance. We investigated the influence of variations in the physical and predictive properties of color stimuli in several different operant-conditioning procedures on the subsequent learning performance. These procedures included context and stimulus generalization as well as color, compound, and conditional discrimination (colors and patterns). A surprisingly complex dependence of the learning performance on the colors' physical and predictive properties emerged, which was clarified by taking into account the fly-subjective perception of the color stimuli. Based on estimates of the stimuli's color and brightness values, we propose that the different tasks are supported by different parameters of the color stimuli; generalization occurs only if the chromaticity is sufficiently similar, whereas discrimination learning relies on brightness differences.

Instrumental colour of Iberian ham subcutaneous fat and lean (biceps femoris): Influence of crossbreeding and rearing system.

PubMed

Carrapiso, Ana I; García, Carmen

2005-10-01

The influence of crossbreeding (Iberian vs Iberian×Duroc 50% pigs) and rearing system (Montanera vs Pienso) on the instrumental colour of Iberian ham (subcutaneous fat and biceps femoris muscle) and the relationships to sensory appearance and chemical composition were researched by using a factorial design. In subcutaneous fat, a significant effect (p<0.05) of crossbreeding and rearing system was found: b* and chroma were larger in hams from Iberian pigs than from Iberian×Duroc (50%) pigs, and L*, a* and chroma were larger in Pienso hams than in Montanera hams. CIEL*a*b* variables of subcutaneous fat were closely related to subcutaneous fatty acid composition, the largest correlationships involving L* (L* and 18:0, 0.652, p<0.001; L* and 18:1, -0.616, p<0.001). Instrumental colour variables and sensory appearance were also correlated (L* and fat pinkness, -0.539, p<0.001). In lean (biceps femoris), instrumental colour data was not affected by crossbreeding and rearing system. CIEL*a*b* variables were not related to chemical composition (moisture, NaCl, intramuscular fat and pigment content), although they were correlated to sensory appearance (L* and marbling, 0.419, p=0.014).

Multicolor Super-Resolution Fluorescence Imaging via Multi-Parameter Fluorophore Detection

PubMed Central

Bates, Mark; Dempsey, Graham T; Chen, Kok Hao; Zhuang, Xiaowei

2012-01-01

Understanding the complexity of the cellular environment will benefit from the ability to unambiguously resolve multiple cellular components, simultaneously and with nanometer-scale spatial resolution. Multicolor super-resolution fluorescence microscopy techniques have been developed to achieve this goal, yet challenges remain in terms of the number of targets that can be simultaneously imaged and the crosstalk between color channels. Herein, we demonstrate multicolor stochastic optical reconstruction microscopy (STORM) based on a multi-parameter detection strategy, which uses both the fluorescence activation wavelength and the emission color to discriminate between photo-activatable fluorescent probes. First, we obtained two-color super-resolution images using the near-infrared cyanine dye Alexa 750 in conjunction with a red cyanine dye Alexa 647, and quantified color crosstalk levels and image registration accuracy. Combinatorial pairing of these two switchable dyes with fluorophores which enhance photo-activation enabled multi-parameter detection of six different probes. Using this approach, we obtained six-color super-resolution fluorescence images of a model sample. The combination of multiple fluorescence detection parameters for improved fluorophore discrimination promises to substantially enhance our ability to visualize multiple cellular targets with sub-diffraction-limit resolution. PMID:22213647

Accuracy of color prediction of anthraquinone dyes in methanol solution estimated from first principle quantum chemistry computations.

PubMed

Cysewski, Piotr; Jeliński, Tomasz

2013-10-01

The electronic spectrum of four different anthraquinones (1,2-dihydroxyanthraquinone, 1-aminoanthraquinone, 2-aminoanthraquinone and 1-amino-2-methylanthraquinone) in methanol solution was measured and used as reference data for theoretical color prediction. The visible part of the spectrum was modeled according to TD-DFT framework with a broad range of DFT functionals. The convoluted theoretical spectra were validated against experimental data by a direct color comparison in terms of CIE XYZ and CIE Lab tristimulus model color. It was found, that the 6-31G** basis set provides the most accurate color prediction and there is no need to extend the basis set since it does not improve the prediction of color. Although different functionals were found to give the most accurate color prediction for different anthraquinones, it is possible to apply the same DFT approach for the whole set of analyzed dyes. Especially three functionals seem to be valuable, namely mPW1LYP, B1LYP and PBE0 due to very similar spectra predictions. The major source of discrepancies between theoretical and experimental spectra comes from L values, representing the lightness, and the a parameter, depicting the position on green→magenta axis. Fortunately, the agreement between computed and observed blue→yellow axis (parameter b) is very precise in the case of studied anthraquinone dyes in methanol solution. Despite discussed shortcomings, color prediction from first principle quantum chemistry computations can lead to quite satisfactory results, expressed in terms of color space parameters.

[Effect of bleaching agents on the color of indirect and direct composite resins].

PubMed

Xing, Wenzhong; Jiang, Tao; Chen, Xiaodong; Wang, Yining

2014-09-01

To evaluate the effect of bleaching agents on the color of indirect and direct composite resins. Five resin composite materials were tested in this in vitro study. The five composites were as follow: two indirect composite resins (Adoro SR, Ceramage) and three direct composite resins (Filtek Z350, Clearfil Majesty Esthetic, and Gradia Direct Anterior). For each material, twenty disk-shaped specimens were prepared and randomly divided into five groups according to the color parameters of specimens before bleaching treatment. The composite resin specimens were treated by one of five sample solutions which were at-home bleaching agents (10% and 15% carbarmide peroxide), in- office bleaching agents (38% H(2)O(2) and 35%H(2)O(2)) and deionized water (control group). The color parameters of specimens were measured by spectrophotometer at baseline and after bleaching treatments. The color differences (ΔE values) between baseline and post-treatments were calculated. The data of color differences were evaluated statistically using two-way analysis with a significance level of 0.05. The color changes of the resin composites were less than 2.0 after bleaching agent treatment, therefore were not perceptible. Slight increase of L(*) values and decrease of C(*)ab values in color parameters of specimens were observed. There were statistically significant differences in ΔE values for different bleaching treatments and resin materials (P = 0.001). The bleaching agents did not affect the color of indirect and direct composite resins tested.

Production and characterization of refined oils obtained from Indian oil sardine (Sardinella longiceps).

PubMed

Chakraborty, Kajal; Joseph, Deepu

2015-01-28

Crude Sardinella longiceps oil was refined in different stages such as degumming, neutralization, bleaching, and deodorization. The efficiency of these processes was evaluated on the basis of free fatty acid (FFA), peroxide (PV), p-anisidine (pAV), total oxidation (TOTOX), thiobarbituric acid reactive species (TBARS) values, Lovibond CIE-L*a*b* color analyses, and (1)H NMR or GC-MS experiments. The utilities of NMR-based proton signal characteristics as new analytical tools to understand the signature peaks and relative abundance of different fatty acids and monitoring the refining process of fish oil have been demonstrated. Phosphoric acid (1%) was found to be an effective degumming reagent to obtain oil with the lowest FFA, PV, pAV, TOTOX, and TBARS values and highest color reduction. Significant reduction in the contents of hydrocarbon functionalities as shown by the decrease in proton integral in the characteristic (1)H NMR region was demonstrated by using 1% H3PO4 during the course of the degumming process. A combination (1.25:3.75%) of activated charcoal and Fuller's earth at 3% concentration for a stirring time of 40 min was found to be effective in bleaching the sardine oil. This study demonstrated that unfavorable odor-causing components, particularly low molecular weight carbonyl compounds, could successfully be removed by the refining process. The alkane-dienals/alkanes, which cause unfavorable fishy odors, were successfully removed by distillation (100 °C) under vacuum with aqueous acetic acid solution (0.25 N) to obtain greater quality of refined sardine oil, a rich source of essential fatty acids and improved oxidative stability. The present study demonstrated that the four-stage refinement process of sardine oil resulted in a significant improvement in quality characteristics and nutritional values, particularly n-3 PUFAs, with improved fish oil characteristics for use in the pharmaceutical and functional food industries.

Reliability of conventional shade guides in teeth color determination.

PubMed

Todorović, Ana; Todorović, Aleksandar; Gostović, Aleksandra Spadijer; Lazić, Vojkan; Milicić, Biljana; Djurisić, Slobodan

2013-10-01

Color matching in prosthodontic therapy is a very important task because it influences the esthetic value of dental restorations. Visual shade matching represents the most frequently applied method in clinical practice. Instrumental measurements provide objective and quantified data in color assessment of natural teeth and restorations. In instrumental shade analysis, the goal is to achieve the smallest deltaE value possible, indicating the most accurate shade match. The aim of this study was to evaluate the reliability of commercially available ceramic shade guides. VITA Easyshade spectrophotometer (VITA, Germany) was used for instrumental color determination. Utilizing this device, color samples of ten VITA Classical and ten VITA 3D - Master shade guides were analyzed. Each color sample from all shade guides was measured three times and the basic parameters of color quality were examined: deltaL, deltaC, deltaH, deltaE, deltaElc. Based on these parameters spectrophotometer marks the shade matching as good, fair or adjust. After performing 1,248 measurements of ceramic color samples, frequency of evaluations adjust, fair and good were statistically significantly different between VITA Classical and VITA 3D Master shade guides (p = 0.002). There were 27.1% cases scored as adjust, 66.3% as fair and 6.7% as good. In VITA 3D - Master shade guides 30.9% cases were evaluated as adjust, 66.4% as fair and 2.7% cases as good. Color samples from different shade guides, produced by the same manufacturer, show variability in basic color parameters, which once again proves the lack of precision and nonuniformity of the conventional method.

Influence of three different concentration techniques on evaporation rate, color and phenolics content of blueberry juice.

PubMed

Elik, Aysel; Yanık, Derya Koçak; Maskan, Medeni; Göğüş, Fahrettin

2016-05-01

The present study was undertaken to assess the effects of three different concentration processes open-pan, rotary vacuum evaporator and microwave heating on evaporation rate, the color and phenolics content of blueberry juice. Kinetics model study for changes in soluble solids content (°Brix), color parameters and phenolics content during evaporation was also performed. The final juice concentration of 65° Brix was achieved in 12, 15, 45 and 77 min, for microwave at 250 and 200 W, rotary vacuum and open-pan evaporation processes, respectively. Color changes associated with heat treatment were monitored using Hunter colorimeter (L*, a* and b*). All Hunter color parameters decreased with time and dependently studied concentration techniques caused color degradation. It was observed that the severity of color loss was higher in open-pan technique than the others. Evaporation also affected total phenolics content in blueberry juice. Total phenolics loss during concentration was highest in open-pan technique (36.54 %) and lowest in microwave heating at 200 W (34.20 %). So, the use of microwave technique could be advantageous in food industry because of production of blueberry juice concentrate with a better quality and short time of operation. A first-order kinetics model was applied to modeling changes in soluble solids content. A zero-order kinetics model was used to modeling changes in color parameters and phenolics content.

AIRS Maps from Space Processing Software

NASA Technical Reports Server (NTRS)

Thompson, Charles K.; Licata, Stephen J.

2012-01-01

This software package processes Atmospheric Infrared Sounder (AIRS) Level 2 swath standard product geophysical parameters, and generates global, colorized, annotated maps. It automatically generates daily and multi-day averaged colorized and annotated maps of various AIRS Level 2 swath geophysical parameters. It also generates AIRS input data sets for Eyes on Earth, Puffer-sphere, and Magic Planet. This program is tailored to AIRS Level 2 data products. It re-projects data into 1/4-degree grids that can be combined and averaged for any number of days. The software scales and colorizes global grids utilizing AIRS-specific color tables, and annotates images with title and color bar. This software can be tailored for use with other swath data products for the purposes of visualization.

Determining Sala mango qualities with the use of RGB images captured by a mobile phone camera

NASA Astrophysics Data System (ADS)

Yahaya, Ommi Kalsom Mardziah; Jafri, Mohd Zubir Mat; Aziz, Azlan Abdul; Omar, Ahmad Fairuz

2015-04-01

Sala mango (Mangifera indicia) is one of the Malaysia's most popular tropical fruits that are widely marketed within the country. The degrees of ripeness of mangoes have conventionally been evaluated manually on the basis of color parameters, but a simple non-destructive technique using the Samsung Galaxy Note 1 mobile phone camera is introduced to replace the destructive technique. In this research, color parameters in terms of RGB values acquired using the ENVI software system were linked to detect Sala mango quality parameters. The features of mango were extracted from the acquired images and then used to classify of fruit skin color, which relates to the stages of ripening. A multivariate analysis method, multiple linear regression, was employed with the purpose of using RGB color parameters to estimate the pH, soluble solids content (SSC), and firmness. The relationship between these qualities parameters of Sala mango and its mean pixel values in the RGB system is analyzed. Findings show that pH yields the highest accuracy with a correlation coefficient R = 0.913 and root mean square of error RMSE = 0.166 pH. Meanwhile, firmness has R = 0.875 and RMSE = 1.392 kgf, whereas soluble solid content has the lowest accuracy with R = 0.814 and RMSE = 1.218°Brix with the correlation between color parameters. Therefore, this non-invasive method can be used to determine the quality attributes of mangoes.

Determining the accuracy of maximum likelihood parameter estimates with colored residuals

NASA Technical Reports Server (NTRS)

Morelli, Eugene A.; Klein, Vladislav

1994-01-01

An important part of building high fidelity mathematical models based on measured data is calculating the accuracy associated with statistical estimates of the model parameters. Indeed, without some idea of the accuracy of parameter estimates, the estimates themselves have limited value. In this work, an expression based on theoretical analysis was developed to properly compute parameter accuracy measures for maximum likelihood estimates with colored residuals. This result is important because experience from the analysis of measured data reveals that the residuals from maximum likelihood estimation are almost always colored. The calculations involved can be appended to conventional maximum likelihood estimation algorithms. Simulated data runs were used to show that the parameter accuracy measures computed with this technique accurately reflect the quality of the parameter estimates from maximum likelihood estimation without the need for analysis of the output residuals in the frequency domain or heuristically determined multiplication factors. The result is general, although the application studied here is maximum likelihood estimation of aerodynamic model parameters from flight test data.

Preliminary assessments of portable color spectrophotometer measurements of cotton color

USDA-ARS?s Scientific Manuscript database

Cotton in the U.S. is classified for color with the Uster® High Volume Instrument (HVI), using the parameters Rd (diffuse reflectance) and +b (yellowness). It has been reported that some cotton bales, especially those transported overseas, appear to have changed significantly in color from their in...

Atlantic salmon skin and fillet color changes effected by perimortem handling stress, rigor mortis, and ice storage.

PubMed

Erikson, U; Misimi, E

2008-03-01

The changes in skin and fillet color of anesthetized and exhausted Atlantic salmon were determined immediately after killing, during rigor mortis, and after ice storage for 7 d. Skin color (CIE L*, a*, b*, and related values) was determined by a Minolta Chroma Meter. Roche SalmoFan Lineal and Roche Color Card values were determined by a computer vision method and a sensory panel. Before color assessment, the stress levels of the 2 fish groups were characterized in terms of white muscle parameters (pH, rigor mortis, and core temperature). The results showed that perimortem handling stress initially significantly affected several color parameters of skin and fillets. Significant transient fillet color changes also occurred in the prerigor phase and during the development of rigor mortis. Our results suggested that fillet color was affected by postmortem glycolysis (pH drop, particularly in anesthetized fillets), then by onset and development of rigor mortis. The color change patterns during storage were different for the 2 groups of fish. The computer vision method was considered suitable for automated (online) quality control and grading of salmonid fillets according to color.

Analysis on unevenness of skin color using the melanin and hemoglobin components separated by independent component analysis of skin color image

NASA Astrophysics Data System (ADS)

Ojima, Nobutoshi; Fujiwara, Izumi; Inoue, Yayoi; Tsumura, Norimichi; Nakaguchi, Toshiya; Iwata, Kayoko

2011-03-01

Uneven distribution of skin color is one of the biggest concerns about facial skin appearance. Recently several techniques to analyze skin color have been introduced by separating skin color information into chromophore components, such as melanin and hemoglobin. However, there are not many reports on quantitative analysis of unevenness of skin color by considering type of chromophore, clusters of different sizes and concentration of the each chromophore. We propose a new image analysis and simulation method based on chromophore analysis and spatial frequency analysis. This method is mainly composed of three techniques: independent component analysis (ICA) to extract hemoglobin and melanin chromophores from a single skin color image, an image pyramid technique which decomposes each chromophore into multi-resolution images, which can be used for identifying different sizes of clusters or spatial frequencies, and analysis of the histogram obtained from each multi-resolution image to extract unevenness parameters. As the application of the method, we also introduce an image processing technique to change unevenness of melanin component. As the result, the method showed high capabilities to analyze unevenness of each skin chromophore: 1) Vague unevenness on skin could be discriminated from noticeable pigmentation such as freckles or acne. 2) By analyzing the unevenness parameters obtained from each multi-resolution image for Japanese ladies, agerelated changes were observed in the parameters of middle spatial frequency. 3) An image processing system modulating the parameters was proposed to change unevenness of skin images along the axis of the obtained age-related change in real time.

Effect of protective atmosphere on color of goose meat.

PubMed

Orkusz, A; Woloszyn, J; Haraf, G; Okruszek, A

2013-08-01

The objective of the work was to characterize the color of the of the goose breast meat packaged in protective atmosphere and stored in the refrigerated conditions. The aim was realized by determination of total heme pigment concentration; relative concentration of myoglobin, oxymyoglobin, and metmyoglobin; parameters of color L* (lightness), a* (redness), and b* (yellowness); and sensory evaluation of the surface color. The experimental material was White Kołuda goose boneless breast meat with the skin from industrial slaughter. The following 2 protective atmospheres were used in the study: vacuum and modified atmosphere (MA) consisting of 80% O2 and 20% CO2. The muscles packed in protective atmosphere were examined on d 4, 7, 11, and 14 of storage. A control sample was goose breast meat stored in air and tested after 24 h after slaughter. The total pigment concentration decreased gradually within 14 d of storage for samples packed in 2 types of atmospheres. The increase in relative concentration of metmyoglobin and the decrease in oxymyoglobin relative concentration in total heme pigments in the meat stored in MA was noticed. However, in all times of storage, the relative concentration of the 3 samples of myoglobin forms stored in vacuum was unchanged. The color parameters (L*, a*, b*) did not change for 14 d of storage in the muscles packed in vacuum. One can state a decrease of the value of the color parameter a* as well as an increase of the value of the color parameter b* in the samples packed in MA. From d 11 to 14 of storage, goose meat packed under MA had lower sensory evaluation intensity of color than muscles under vacuum. The obtained data indicated that the surface color of goose breast meat packed in MA (consisting of 80% O2, 20% CO2) or vacuum packed was maintained for 11 and 14 d, respectively.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Shengqiang; Li, Jie; Yu, Junsheng, E-mail: jsyu@uestc.edu.cn

A color tuning index (I{sub CT}) parameter for evaluating the color change capability of color-tunable organic light-emitting diodes (CT-OLEDs) was proposed and formulated. And a series of CT-OLEDs, consisting of five different carrier/exciton adjusting interlayers (C/EALs) inserted between two complementary emitting layers, were fabricated and applied to disclose the relationship between I{sub CT} and C/EALs. The result showed that the trend of electroluminescence spectra behavior in CT-OLEDs has good accordance with I{sub CT} values, indicating that the I{sub CT} parameter is feasible for the evaluation of color variation. Meanwhile, by changing energy level and C/EAL thickness, the optimized device withmore » the widest color tuning range was based on N,N′-dicarbazolyl-3,5-benzene C/EAL, exhibiting the highest I{sub CT} value of 41.2%. Based on carrier quadratic hopping theory and exciton transfer model, two fitting I{sub CT} formulas derived from the highest occupied molecular orbital (HOMO) energy level and triplet energy level were simulated. Finally, a color tuning prediction (CTP) model was developed to deduce the I{sub CT} via C/EAL HOMO and triplet energy levels, and verified by the fabricated OLEDs with five different C/EALs. We believe that the CTP model assisted with I{sub CT} parameter will be helpful for fabricating high performance CT-OLEDs with a broad range of color tuning.« less

Factors that determin color appearance and color classification.

PubMed

Janelidze, D

2011-11-01

The purpose of this work was to consider the objective and subjective factors involved in color perception and on their basis offer a color classification that would allow for determining which of these factors are significant for each particular class of colors. In the first part of the article it is considered that physical correlates of subjective sensation of color have mainly a dual nature and sometimes correlate with spectral-power content of light coming from a given area of visual scene to retina, and sometimes with surface reflectance of the given area. Other objective and subjective factors which participate in the formation of color appearance are also considered. According to the characteristics of the visual stimulus, viewing conditions and functional state of visual system, composition of objective and subjective factors participating in the formation of color appearance, as well as the share of each factor in this process are changeable. In the second part of the article one of the possible version of color classification according to which it is possible to distinguish nine different classes of colors is proposed. Among differences between these classes, the most noticeable is that in the case of all classes of color except constant colors, the physical parameter that determines the color category of a given area is the spectral-power distribution of the light coming from this area to the retina. However, in the case of constant colors, the physical parameter that determines the color category of a given area is its reflectance. In the case of considered different classes of colors, composition of objective and subjective factors participating in the formation of color appearance is different. The proposed classification allows determining which of these factors are significant in the case of each specific class of color.

Statistical simplex approach to primary and secondary color correction in thick lens assemblies

NASA Astrophysics Data System (ADS)

Ament, Shelby D. V.; Pfisterer, Richard

2017-11-01

A glass selection optimization algorithm is developed for primary and secondary color correction in thick lens systems. The approach is based on the downhill simplex method, and requires manipulation of the surface color equations to obtain a single glass-dependent parameter for each lens element. Linear correlation is used to relate this parameter to all other glass-dependent variables. The algorithm provides a statistical distribution of Abbe numbers for each element in the system. Examples of several lenses, from 2-element to 6-element systems, are performed to verify this approach. The optimization algorithm proposed is capable of finding glass solutions with high color correction without requiring an exhaustive search of the glass catalog.

Entrainment to the CIECAM02 and CIELAB colour appearance models in the human cortex.

PubMed

Thwaites, Andrew; Wingfield, Cai; Wieser, Eric; Soltan, Andrew; Marslen-Wilson, William D; Nimmo-Smith, Ian

2018-04-01

In human visual processing, information from the visual field passes through numerous transformations before perceptual attributes such as colour are derived. The sequence of transforms involved in constructing perceptions of colour can be approximated by colour appearance models such as the CIE (2002) colour appearance model, abbreviated as CIECAM02. In this study, we test the plausibility of CIECAM02 as a model of colour processing by looking for evidence of its cortical entrainment. The CIECAM02 model predicts that colour is split in to two opposing chromatic components, red-green and cyan-yellow (termed CIECAM02-a and CIECAM02-b respectively), and an achromatic component (termed CIECAM02-A). Entrainment of cortical activity to the outputs of these components was estimated using measurements of electro- and magnetoencephalographic (EMEG) activity, recorded while healthy subjects watched videos of dots changing colour. We find entrainment to chromatic component CIECAM02-a at approximately 35 ms latency bilaterally in occipital lobe regions, and entrainment to achromatic component CIECAM02-A at approximately 75 ms latency, also bilaterally in occipital regions. For comparison, transforms from a less physiologically plausible model (CIELAB) were also tested, with no significant entrainment found. Copyright © 2018 Elsevier Ltd. All rights reserved.

Natural extracts versus sodium ascorbate to extend the shelf life of meat-based ready-to-eat meals.

PubMed

Price, Alejandra; Díaz, Pedro; Bañón, Sancho; Garrido, Maria Dolores

2013-10-01

The effect of grape seed and green tea extracts was compared with effect of sodium ascorbate on bacterial spoilage, lipid stability and sensory quality in cooked pork meatballs during refrigerated storage. Meatballs were stored at 4  in aerobic packaging for 0, 4, 8, 12 and 16 days under retail display conditions. Lipid oxidation was evaluated as thiobarbituric acid reactive substances, volatile compounds and cholesterol oxidation products. Colour stability was assessed through CIELab parameters. Microbiological spoilage was determined through total viable, mould and yeast and coliform counts. The samples containing green tea and grape seed extracts showed lower levels of thiobarbituric acid reacting substances, major volatile compounds and microbiological counts than the samples with sodium ascorbate. Formation of cholesterol oxidation products was also inhibited to a greater extent. Colour of meatballs and pork meatballs was not affected by refrigerated storage; however, the addition of extracts provided brown shades. The addition of antioxidants did not modify the sensory attributes except for the colour. Green tea and grape seed extracts were more effective than sodium ascorbate at preventing lipid oxidation.

Effect of accelerated weathering on surface chemistry of modified wood

NASA Astrophysics Data System (ADS)

Temiz, Ali; Terziev, Nasko; Eikenes, Morten; Hafren, Jonas

2007-04-01

In this study, the effects of UV-light irradiation and water spray on colour and surface chemistry of scots pine sapwood samples were investigated. The specimens were treated with chromated copper arsenate (CCA), a metal-free propiconazol-based formulation, chitosan, furfuryl alcohol and linseed and tall oils. The weathering experiment was performed by cycles of 2 h UV-light irradiation followed by water spray for 18 min. The changes at the surface of the weathered samples were characterised by Fourier transform infrared spectroscopy (FT-IR); colour characterizations were performed by measuring CIELab parameters. The results show that all treatment methods except chitosan treatment provided lower colour changes than the control groups after 800 h exposure in weathering test cycle, but differences between chitosan and control were also small. The lowest colour changes were found on linseed oil (full cell process) and CCA treated wood. FT-IR results show that oil treatment (linseed and tall oil) decreased the intensities of a lignin specific peak (1500-1515 cm -1). Absorption band changes at 1630-1660 cm -1 were reduced by all treatments.

Automatic color preference correction for color reproduction

NASA Astrophysics Data System (ADS)

Tsukada, Masato; Funayama, Chisato; Tajima, Johji

2000-12-01

The reproduction of natural objects in color images has attracted a great deal of attention. Reproduction more pleasing colors of natural objects is one of the methods available to improve image quality. We developed an automatic color correction method to maintain preferred color reproduction for three significant categories: facial skin color, green grass and blue sky. In this method, a representative color in an object area to be corrected is automatically extracted from an input image, and a set of color correction parameters is selected depending on the representative color. The improvement in image quality for reproductions of natural image was more than 93 percent in subjective experiments. These results show the usefulness of our automatic color correction method for the reproduction of preferred colors.

Automatic Cloud Classification from Multi-Spectral Satellite Data Over Oceanic Regions

DTIC Science & Technology

1992-01-14

parameters the first two colors used are, blue for low values and dark green for high parameter values. If a third class is identified, the intermediate...intermediate yellow and high dark green classes. The color sequence blue-yellow-light green- dark green, then characterizes the low to high parameter value...to light green then to dark green correspond to superpixels of increasing (from low to high) variability in their altitude, (see Table V.3). When the

Effects of Fibers on Color and Translucency Changes of Bulk-Fill and Anterior Composites after Accelerated Aging

PubMed Central

Güven, Mehmet Esad

2018-01-01

The aim of this study was to determine the effects of glass and polyethylene fibers on the color and translucency change of bulk-fill and anterior composites before and after artificial accelerated aging (AAA). Two types of teflon molds were used to fabricate samples which were 13 mm in diameter and, respectively, 2 mm and 4 mm in height. Polyethylene fiber (PF) and glass fiber (GF) were incorporated in the middle of the composite samples. Color and translucency changes of each composite were evaluated before and after AAA with spectrophotometer. ANOVA and Tukey's HSD post hoc statistical analysis were used at a significance level of 0.05. Before AAA (for anterior composites), there were no significant differences in L* and b* parameters among the three groups (p > 0.05); there were no significant differences in L* parameter between PF and GF groups or in TP between GF and control groups (p > 0.05) (for bulk-fill composites). After AAA, there were no significant differences in L* parameter between GF and control groups, in a* parameter between PF and control groups, in b* parameter among all groups, or in TP parameter between GF and control groups (p > 0.05). Fiber reinforcement led to color and TP change in both anterior and bulk-fill resin composites. PMID:29850499

Developing a machine vision system for simultaneous prediction of freshness indicators based on tilapia (Oreochromis niloticus) pupil and gill color during storage at 4°C.

PubMed

Shi, Ce; Qian, Jianping; Han, Shuai; Fan, Beilei; Yang, Xinting; Wu, Xiaoming

2018-03-15

The study assessed the feasibility of developing a machine vision system based on pupil and gill color changes in tilapia for simultaneous prediction of total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA) and total viable counts (TVC) during storage at 4°C. The pupils and gills were chosen and color space conversion among RGB, HSI and L ∗ a ∗ b ∗ color spaces was performed automatically by an image processing algorithm. Multiple regression models were established by correlating pupil and gill color parameters with TVB-N, TVC and TBA (R 2 =0.989-0.999). However, assessment of freshness based on gill color is destructive and time-consuming because gill cover must be removed before images are captured. Finally, visualization maps of spoilage based on pupil color were achieved using image algorithms. The results show that assessment of tilapia pupil color parameters using machine vision can be used as a low-cost, on-line method for predicting freshness during 4°C storage. Copyright © 2017 Elsevier Ltd. All rights reserved.

ULTRAVIOLET PROPERTIES OF GALACTIC GLOBULAR CLUSTERS WITH GALEX. II. INTEGRATED COLORS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dalessandro, Emanuele; Ferraro, Francesco R.; Lanzoni, Barbara

2012-11-01

We present ultraviolet (UV) integrated colors of 44 Galactic globular clusters (GGCs) observed with the Galaxy Evolution Explorer (GALEX) in both FUV and NUV bands. This database is the largest homogeneous catalog of UV colors ever published for stellar systems in our Galaxy. The proximity of GGCs makes it possible to resolve many individual stars even with the somewhat low spatial resolution of GALEX. This allows us to determine how the integrated UV colors are driven by hot stellar populations, primarily horizontal branch stars and their progeny. The UV colors are found to be correlated with various parameters commonly usedmore » to define the horizontal branch morphology. We also investigate how the UV colors vary with parameters like metallicity, age, helium abundance, and concentration. We find for the first time that GCs associated with the Sagittarius dwarf galaxy have (FUV - V) colors systematically redder than GGCs with the same metallicity. Finally, we speculate about the presence of an interesting trend, suggesting that the UV color of GCs may be correlated with the mass of the host galaxy, in the sense that more massive galaxies possess bluer clusters.« less

Security of Color Image Data Designed by Public-Key Cryptosystem Associated with 2D-DWT

NASA Astrophysics Data System (ADS)

Mishra, D. C.; Sharma, R. K.; Kumar, Manish; Kumar, Kuldeep

2014-08-01

In present times the security of image data is a major issue. So, we have proposed a novel technique for security of color image data by public-key cryptosystem or asymmetric cryptosystem. In this technique, we have developed security of color image data using RSA (Rivest-Shamir-Adleman) cryptosystem with two-dimensional discrete wavelet transform (2D-DWT). Earlier proposed schemes for security of color images designed on the basis of keys, but this approach provides security of color images with the help of keys and correct arrangement of RSA parameters. If the attacker knows about exact keys, but has no information of exact arrangement of RSA parameters, then the original information cannot be recovered from the encrypted data. Computer simulation based on standard example is critically examining the behavior of the proposed technique. Security analysis and a detailed comparison between earlier developed schemes for security of color images and proposed technique are also mentioned for the robustness of the cryptosystem.

Colored noise effects on batch attitude accuracy estimates

NASA Technical Reports Server (NTRS)

Bilanow, Stephen

1991-01-01

The effects of colored noise on the accuracy of batch least squares parameter estimates with applications to attitude determination cases are investigated. The standard approaches used for estimating the accuracy of a computed attitude commonly assume uncorrelated (white) measurement noise, while in actual flight experience measurement noise often contains significant time correlations and thus is colored. For example, horizon scanner measurements from low Earth orbit were observed to show correlations over many minutes in response to large scale atmospheric phenomena. A general approach to the analysis of the effects of colored noise is investigated, and interpretation of the resulting equations provides insight into the effects of any particular noise color and the worst case noise coloring for any particular parameter estimate. It is shown that for certain cases, the effects of relatively short term correlations can be accommodated by a simple correction factor. The errors in the predicted accuracy assuming white noise and the reduced accuracy due to the suboptimal nature of estimators that do not take into account the noise color characteristics are discussed. The appearance of a variety of sample noise color characteristics are demonstrated through simulation, and their effects are discussed for sample estimation cases. Based on the analysis, options for dealing with the effects of colored noise are discussed.

The Effect of Core and Veneering Design on the Optical Properties of Polyether Ether Ketone.

PubMed

Zeighami, S; Mirmohammadrezaei, S; Safi, M; Falahchai, S M

2017-12-01

This study aimed to evaluate the effect of core shade and core and veneering thickness on color parameters and translucency of polyether ether ketone (PEEK). Sixty PEEK discs (0.5 and 1 mm in thickness) with white and dentine shades were veneered with A2 shade indirect composite resin with 0.5, 1 and 1.5 mm thickness (n=5). Cores without the veneering material served as controls for translucency evaluation. Color parameters were measured by a spectroradiometer. Color difference (ΔE₀₀) and translucency parameters (TP) were computed. Data were analyzed using one-way ANOVA and Tukey's test (for veneering thickness) and independent t-test (for core shade and thickness) via SPSS 20.0 (p⟨0.05). Regarding the veneering thickness, white cores of 0.5 mm thickness showed significant differences in all color parameters. In white cores of 1 mm thickness and dentine cores of 0.5 and 1 mm thickness, there were statistically significant differences only in L∗, a∗ and h∗. The mean TP was significantly higher in all white cores of 1 mm thickness than dentine cores of 1 mm. Considering ΔE₀₀=3.7 as clinically unacceptable, only three groups had higher mean ΔE₀₀ values. Core shade, core thickness, and the veneering thickness affected the color and translucency of PEEK restorations. Copyright© 2017 Dennis Barber Ltd.

[Nitrogen status diagnosis of rice by using a digital camera].

PubMed

Jia, Liang-Liang; Fan, Ming-Sheng; Zhang, Fu-Suo; Chen, Xin-Ping; Lü, Shi-Hua; Sun, Yan-Ming

2009-08-01

In the present research, a field experiment with different N application rate was conducted to study the possibility of using visible band color analysis methods to monitor the N status of rice canopy. The Correlations of visible spectrum band color intensity between rice canopy image acquired from a digital camera and conventional nitrogen status diagnosis parameters of leaf SPAD chlorophyll meter readings, total N content, upland biomass and N uptake were studied. The results showed that the red color intensity (R), green color intensity (G) and normalized redness intensity (NRI) have significant inverse linear correlations with the conventional N diagnosis parameters of SPAD readings, total N content, upland biomass and total N uptake. The correlation coefficient values (r) were from -0.561 to -0.714 for red band (R), from -0.452 to -0.505 for green band (G), and from -0.541 to 0.817 for normalized redness intensity (NRI). But the normalized greenness intensity (NGI) showed a significant positive correlation with conventional N parameters and the correlation coefficient values (r) were from 0.505 to 0.559. Compared with SPAD readings, the normalized redness intensity (NRI), with a high r value of 0.541-0.780 with conventional N parameters, could better express the N status of rice. The digital image color analysis method showed the potential of being used in rice N status diagnosis in the future.

The impact of individual materials parameters on color temperature reproducibility among phosphor converted LED sources

NASA Astrophysics Data System (ADS)

Schweitzer, Susanne; Nemitz, Wolfgang; Sommer, Christian; Hartmann, Paul; Fulmek, Paul; Nicolics, Johann; Pachler, Peter; Hoschopf, Hans; Schrank, Franz; Langer, Gregor; Wenzl, Franz P.

2014-09-01

For a systematic approach to improve the white light quality of phosphor converted light-emitting diodes (LEDs) for general lighting applications it is imperative to get the individual sources of error for color temperature reproducibility under control. In this regard, it is imperative to understand how compositional, optical and materials properties of the color conversion element (CCE), which typically consists of phosphor particles embedded in a transparent matrix material, affect the constancy of a desired color temperature of a white LED source. In this contribution we use an LED assembly consisting of an LED die mounted on a printed circuit board (PCB) by chip-on-board technology and a CCE with a glob-top configuration as a model system and discuss the impact of potential sources for color temperature deviation among individual devices. Parameters that are investigated include imprecisions in the amount of materials deposition, deviations from the target value for the phosphor concentration in the matrix material, deviations from the target value for the particle sizes of the phosphor material, deviations from the target values for the refractive indexes of phosphor and matrix material as well as deviations from the reflectivity of the substrate surface. From these studies, some general conclusions can be drawn which of these parameters have the largest impact on color deviation and have to be controlled most precisely in a fabrication process in regard of color temperature reproducibility among individual white LED sources.

The influence of iris color on the pupillary light reflex.

PubMed

Bergamin, O; Schoetzau, A; Sugimoto, K; Zulauf, M

1998-08-01

This study was carried out to investigate the effect of iris color on the pupillary light reflex (PLR) in normal healthy volunteers. Pupil perimetry was performed on 50 healthy volunteers with the Octopus 1-2-3 automated perimeter. Within the 30-deg visual field, 33 test locations were investigated four times. Stimulus parameters were Goldmann size V (1.72 degrees), intensity 1632 cd/m2, stimulus time 200 ms, background illumination 0 cd/m2, and interstimulus interval 3 s. Pupillometric parameters studied were initial pupil size, amplitude (magnitude of pupillary contraction), latency time, contraction time, pre-PLR movement, contraction velocity, and redilation velocity. Pupillometric parameters were investigated by analysis of variance by the independent variables blue and brown irides. Iris color (blue vs brown) influenced statistically significantly (P < 0.05) amplitude (0.504 mm vs 0.594 mm), contraction time (401 ms vs 407 ms), contraction velocity (13.75 mm2/s vs 16.01 mm2/s), and redilation velocity (4.80 mm2/s vs 5.66 mm2/s). Iris color did not influence initial pupil size (4.78 mm vs 4.83 mm), latency time (520 mm vs 521 ms), and pre-PLR movement (0.328 mm2/s vs 0.325 mm2/s). Pupillary contraction amplitude and velocity depended on iris color, whereas pupil size and latency time were independent of iris color. Therefore, iris color might be considered when, evaluating pupillary movements in pupil perimetry.

Can a bleaching toothpaste containing Blue Covarine demonstrate the same bleaching as conventional techniques? An in vitro, randomized and blinded study.

PubMed

Dantas, Andréa Abi Rached; Bortolatto, Janaina Freitas; Roncolato, Ávery; Merchan, Hugo; Floros, Michael Christopher; Kuga, Milton Carlos; Oliveira Junior, Osmir Batista de

2015-01-01

The purpose of this in vitro study was to compare the efficacy of a bleaching toothpaste containing Blue Covarine vs. conventional tooth bleaching techniques using peroxides (both in-office and at-home). Samples were randomly distributed into five experimental groups (n=15): C - Control; BC - Bleaching toothpaste containing Blue Covarine; WBC - Bleaching toothpaste without Blue Covarine; HP35 - In-office bleaching using 35% hydrogen peroxide; and CP10 - At-home bleaching with 10% carbamide peroxide. The dental bleaching efficacy was determined by the color difference (ΔE), luminosity (ΔL), green-red axis (Δa), and blue-yellow axis (Δb). The CIELab coordinates were recorded with reflectance spectroscopy at different times: T0 - baseline, T1 - immediately after bleaching, T2 - 7 days, T3 - 14 days, and T4 - 21 days after the end of treatments. Data were analyzed by a repeated measures mixed ANOVA and post hoc Bonferroni test, with a significance level of 5%. No significant differences were found between the treatment groups C, BC, and WBC. The groups HP35 and CP10 showed significantly higher whitening efficacy than groups C, BC, and WBC. There were no significant differences in the whitening efficacy between a Blue Covarine containing toothpaste, a standard whitening toothpaste, and a control. Neither of the whitening toothpastes tested were as effective as in-office or at-home bleaching treatments.

Can a bleaching toothpaste containing Blue Covarine demonstrate the same bleaching as conventional techniques? An in vitro, randomized and blinded study

PubMed Central

DANTAS, Andréa Abi Rached; BORTOLATTO, Janaina Freitas; RONCOLATO, Ávery; MERCHAN, Hugo; FLOROS, Michael Christopher; KUGA, Milton Carlos; de OLIVEIRA, Osmir Batista

2015-01-01

ABSTRACT Objective The purpose of this in vitro study was to compare the efficacy of a bleaching toothpaste containing Blue Covarine vs. conventional tooth bleaching techniques using peroxides (both in-office and at-home). Material and Methods Samples were randomly distributed into five experimental groups (n=15): C - Control; BC – Bleaching toothpaste containing Blue Covarine; WBC – Bleaching toothpaste without Blue Covarine; HP35 - In-office bleaching using 35% hydrogen peroxide; and CP10 – At-home bleaching with 10% carbamide peroxide. The dental bleaching efficacy was determined by the color difference (ΔE), luminosity (ΔL), green-red axis (Δa), and blue-yellow axis (Δb). The CIELab coordinates were recorded with reflectance spectroscopy at different times: T0 - baseline, T1 – immediately after bleaching, T2 - 7 days, T3 - 14 days, and T4 - 21 days after the end of treatments. Data were analyzed by a repeated measures mixed ANOVA and post hoc Bonferroni test, with a significance level of 5%. Results No significant differences were found between the treatment groups C, BC, and WBC. The groups HP35 and CP10 showed significantly higher whitening efficacy than groups C, BC, and WBC. Conclusions There were no significant differences in the whitening efficacy between a Blue Covarine containing toothpaste, a standard whitening toothpaste, and a control. Neither of the whitening toothpastes tested were as effective as in-office or at-home bleaching treatments. PMID:26814462

Effect of cold plasma pre-treatment on photocatalytic activity of 3D fabric loaded with nano-photocatalysts: Response surface methodology

NASA Astrophysics Data System (ADS)

Ghoreishian, Seyed Majid; Badii, Khashayar; Norouzi, Mohammad; Malek, Kaveh

2016-03-01

In this study, the physico-chemical effects occasioned by the cold plasma discharge (CPD) on the photo-decolorization of Reactive Orange 16 (RO16) by 3D fabrics (spacer fabrics) loaded with ZnO:TiO2 nano-photocatalysts (nphs) were optimized via response surface methodology (RSM). CPD was employed to improve the surface characteristics of the spacer fabrics for nphs loading. Surface morphology and color variation were studied utilizing scanning electron microscopy (SEM) and CIE-Lab system, respectively. The effect of CPD on the wetting ability of the spacer fabrics was examined using dynamic adsorption measurement (DAM). Also, X-ray fluorescence (XRF) was utilized to investigate the durability of the nphs on the spacer fabrics. All the experiments were implemented in a Box-Behnken design (BBD) with three independent variables (CPD treatment time, dye concentration and irradiation time) in order to optimize the decolorization of RO16. The anticipated values of the decolorization efficiency were found to be in excellent agreement with the experimental values (R2 = 0.9996, Adjusted R2 = 0.9992). The kinetic analysis demonstrated that the photocatalytic decolorization followed the Langmuir-Hinshelwood kinetic model. In conclusion, this heterogeneous photocatalytic process is capable of decolorizing and mineralizing azoic reactive dye in textile wastewater. Moreover, the results confirmed that RSM based on the BBD was a suitable method to optimize the operating conditions of RO16 degradation.

Assessing the effects of severe heat treatment of milk on calcium bioavailability: in vitro and in vivo studies.

PubMed

Seiquer, I; Delgado-Andrade, C; Haro, A; Navarro, M P

2010-12-01

Thermal processing of milk is a common practice. As milk is the main source of dietary calcium, this study aimed to assess the effects of overheating milk on calcium availability. Thus, thermally damaged milk (overheated, OH, milk; 3 cycles of sterilization at 116 °C, 16 min) was compared with UHT milk (150 °C, 6s) in 2 types of assays: in vitro and in vivo (rats). In addition, the greater Maillard reaction rate associated with thermal treatment in OH milk was confirmed by determining specific (furosine) and unspecific markers (CieLab color). A negative effect on calcium solubility was observed after in vitro digestion of OH milk compared with UHT milk. Feeding rats the diet containing OH milk as the protein source led to significantly lower values of apparent calcium absorption and retention than those found among animals fed the UHT milk diet. Whereas reducing the absorption appears to result mainly from the decreased food intake, the negative effect on retention seems to be due to factors derived from milk thermal damage, such as the formation of Maillard reaction products. It was concluded that milk-processing conditions warrant special attention to prevent impaired dietary calcium utilization. This may be especially important in situations where milk and dairy products are the main dietary components, such as in early infancy. Copyright © 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Melanoma recognition framework based on expert definition of ABCD for dermoscopic images.

PubMed

Abbas, Qaisar; Emre Celebi, M; Garcia, Irene Fondón; Ahmad, Waqar

2013-02-01

Melanoma Recognition based on clinical ABCD rule is widely used for clinical diagnosis of pigmented skin lesions in dermoscopy images. However, the current computer-aided diagnostic (CAD) systems for classification between malignant and nevus lesions using the ABCD criteria are imperfect due to use of ineffective computerized techniques. In this study, a novel melanoma recognition system (MRS) is presented by focusing more on extracting features from the lesions using ABCD criteria. The complete MRS system consists of the following six major steps: transformation to the CIEL*a*b* color space, preprocessing to enhance the tumor region, black-frame and hair artifacts removal, tumor-area segmentation, quantification of feature using ABCD criteria and normalization, and finally feature selection and classification. The MRS system for melanoma-nevus lesions is tested on a total of 120 dermoscopic images. To test the performance of the MRS diagnostic classifier, the area under the receiver operating characteristics curve (AUC) is utilized. The proposed classifier achieved a sensitivity of 88.2%, specificity of 91.3%, and AUC of 0.880. The experimental results show that the proposed MRS system can accurately distinguish between malignant and benign lesions. The MRS technique is fully automatic and can easily integrate to an existing CAD system. To increase the classification accuracy of MRS, the CASH pattern recognition technique, visual inspection of dermatologist, contextual information from the patients, and the histopathological tests can be included to investigate the impact with this system. © 2012 John Wiley & Sons A/S.

Optimization of light quality from color mixing light-emitting diode systems for general lighting

NASA Astrophysics Data System (ADS)

Thorseth, Anders

2012-03-01

Given the problem of metamerisms inherent in color mixing in light-emitting diode (LED) systems with more than three distinct colors, a method for optimizing the spectral output of multicolor LED system with regards to standardized light quality parameters has been developed. The composite spectral power distribution from the LEDs are simulated using spectral radiometric measurements of single commercially available LEDs for varying input power, to account for the efficiency droop and other non-linear effects in electrical power vs. light output. The method uses electrical input powers as input parameters in a randomized steepest decent optimization. The resulting spectral power distributions are evaluated with regard to the light quality using the standard characteristics: CIE color rendering index, correlated color temperature and chromaticity distance. The results indicate Pareto optimal boundaries for each system, mapping the capabilities of the simulated lighting systems with regard to the light quality characteristics.

Corrections to MODIS Terra Calibration and Polarization Trending Derived from Ocean Color Products

NASA Technical Reports Server (NTRS)

Meister, Gerhard; Eplee, Robert E.; Franz, Bryan A.

2014-01-01

Remotely sensed ocean color products require highly accurate top-of-atmosphere (TOA) radiances, on the order of 0.5% or better. Due to incidents both prelaunch and on-orbit, meeting this requirement has been a consistent problem for the MODIS instrument on the Terra satellite, especially in the later part of the mission. The NASA Ocean Biology Processing Group (OBPG) has developed an approach to correct the TOA radiances of MODIS Terra using spatially and temporally averaged ocean color products from other ocean color sensors (such as the SeaWiFS instrument on Orbview-2 or the MODIS instrument on the Aqua satellite). The latest results suggest that for MODIS Terra, both linear polarization parameters of the Mueller matrix are temporally evolving. A change to the functional form of the scan angle dependence improved the quality of the derived coefficients. Additionally, this paper demonstrates that simultaneously retrieving polarization and gain parameters improves the gain retrieval (versus retrieving the gain parameter only).

Beyond [lambda][subscript max] Part 2: Predicting Molecular Color

ERIC Educational Resources Information Center

Williams, Darren L.; Flaherty, Thomas J.; Alnasleh, Bassam K.

2009-01-01

A concise roadmap for using computational chemistry programs (i.e., Gaussian 03W) to predict the color of a molecular species is presented. A color-predicting spreadsheet is available with the online material that uses transition wavelengths and peak-shape parameters to predict the visible absorbance spectrum, transmittance spectrum, chromaticity…

Color Image Enhancement Using Multiscale Retinex Based on Particle Swarm Optimization Method

NASA Astrophysics Data System (ADS)

Matin, F.; Jeong, Y.; Kim, K.; Park, K.

2018-01-01

This paper introduces, a novel method for the image enhancement using multiscale retinex and practical swarm optimization. Multiscale retinex is widely used image enhancement technique which intemperately pertains on parameters such as Gaussian scales, gain and offset, etc. To achieve the privileged effect, the parameters need to be tuned manually according to the image. In order to handle this matter, a developed retinex algorithm based on PSO has been used. The PSO method adjusted the parameters for multiscale retinex with chromaticity preservation (MSRCP) attains better outcome to compare with other existing methods. The experimental result indicates that the proposed algorithm is an efficient one and not only provides true color loyalty in low light conditions but also avoid color distortion at the same time.

Statistical Evaluation of VIIRS Ocean Color Products

NASA Astrophysics Data System (ADS)

Mikelsons, K.; Wang, M.; Jiang, L.

2016-02-01

Evaluation and validation of satellite-derived ocean color products is a complicated task, which often relies on precise in-situ measurements for satellite data quality assessment. However, in-situ measurements are only available in comparatively few locations, expensive, and not for all times. In the open ocean, the variability in spatial and temporal scales is longer, and the water conditions are generally more stable. We use this fact to perform extensive statistical evaluations of consistency for ocean color retrievals based on comparison of retrieved data at different times, and corresponding to various retrieval parameters. We have used the NOAA Multi-Sensor Level-1 to Level-2 (MSL12) ocean color data processing system for ocean color product data derived from the Visible Infrared Imaging Radiometer Suite (VIIRS). We show the results for statistical dependence of normalized water-leaving radiance spectra with respect to various parameters of retrieval geometry, such as solar- and sensor-zenith angles, as well as physical variables, such as wind speed, air pressure, ozone amount, water vapor, etc. In most cases, the results show consistent retrievals within the relevant range of retrieval parameters, showing a good performance with the MSL12 in the open ocean. The results also yield the upper bounds of solar- and sensor-zenith angles for reliable ocean color retrievals, and also show a slight increase of VIIRS-derived normalized water-leaving radiances with wind speed and water vapor concentration.

An improved method to estimate reflectance parameters for high dynamic range imaging

NASA Astrophysics Data System (ADS)

Li, Shiying; Deguchi, Koichiro; Li, Renfa; Manabe, Yoshitsugu; Chihara, Kunihiro

2008-01-01

Two methods are described to accurately estimate diffuse and specular reflectance parameters for colors, gloss intensity and surface roughness, over the dynamic range of the camera used to capture input images. Neither method needs to segment color areas on an image, or to reconstruct a high dynamic range (HDR) image. The second method improves on the first, bypassing the requirement for specific separation of diffuse and specular reflection components. For the latter method, diffuse and specular reflectance parameters are estimated separately, using the least squares method. Reflection values are initially assumed to be diffuse-only reflection components, and are subjected to the least squares method to estimate diffuse reflectance parameters. Specular reflection components, obtained by subtracting the computed diffuse reflection components from reflection values, are then subjected to a logarithmically transformed equation of the Torrance-Sparrow reflection model, and specular reflectance parameters for gloss intensity and surface roughness are finally estimated using the least squares method. Experiments were carried out using both methods, with simulation data at different saturation levels, generated according to the Lambert and Torrance-Sparrow reflection models, and the second method, with spectral images captured by an imaging spectrograph and a moving light source. Our results show that the second method can estimate the diffuse and specular reflectance parameters for colors, gloss intensity and surface roughness more accurately and faster than the first one, so that colors and gloss can be reproduced more efficiently for HDR imaging.

Nanosecond laser coloration on stainless steel surface.

PubMed

Lu, Yan; Shi, Xinying; Huang, Zhongjia; Li, Taohai; Zhang, Meng; Czajkowski, Jakub; Fabritius, Tapio; Huttula, Marko; Cao, Wei

2017-08-02

In this work, we present laser coloration on 304 stainless steel using nanosecond laser. Surface modifications are tuned by adjusting laser parameters of scanning speed, repetition rate, and pulse width. A comprehensive study of the physical mechanism leading to the appearance is presented. Microscopic patterns are measured and employed as input to simulate light-matter interferences, while chemical states and crystal structures of composites to figure out intrinsic colors. Quantitative analysis clarifies the final colors and RGB values are the combinations of structural colors and intrinsic colors from the oxidized pigments, with the latter dominating. Therefore, the engineering and scientific insights of nanosecond laser coloration highlight large-scale utilization of the present route for colorful and resistant steels.

Repetition priming in selective attention: A TVA analysis.

PubMed

Ásgeirsson, Árni Gunnar; Kristjánsson, Árni; Bundesen, Claus

2015-09-01

Current behavior is influenced by events in the recent past. In visual attention, this is expressed in many variations of priming effects. Here, we investigate color priming in a brief exposure digit-recognition task. Observers performed a masked odd-one-out singleton recognition task where the target-color either repeated or changed between subsequent trials. Performance was measured by recognition accuracy over exposure durations. The purpose of the study was to replicate earlier findings of perceptual priming in brief displays and to model those results based on a Theory of Visual Attention (TVA; Bundesen, 1990). We tested 4 different definitions of a generic TVA-model and assessed their explanatory power. Our hypothesis was that priming effects could be explained by selective mechanisms, and that target-color repetitions would only affect the selectivity parameter (α) of our models. Repeating target colors enhanced performance for all 12 observers. As predicted, this was only true under conditions that required selection of a target among distractors, but not when a target was presented alone. Model fits by TVA were obtained with a trial-by-trial maximum likelihood estimation procedure that estimated 4-15 free parameters, depending on the particular model. We draw two main conclusions. Color priming can be modeled simply as a change in selectivity between conditions of repetition or swap of target color. Depending on the desired resolution of analysis; priming can accurately be modeled by a simple four parameter model, where VSTM capacity and spatial biases of attention are ignored, or more fine-grained by a 10 parameter model that takes these aspects into account. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of varying core thicknesses and artificial aging on the color difference of different all-ceramic materials.

PubMed

Dikicier, Sibel; Ayyildiz, Simel; Ozen, Julide; Sipahi, Cumhur

2014-11-01

Clinicians should reserve all-ceramics with high translucency for clinical applications in which high-level esthetics are required. Furthermore, it is unclear whether a correlation exists between core thickness and color change. The aim of this study was to examine the effects of different core thicknesses and artificial aging on the color stability of three all-ceramic systems. Ninety disc-shaped cores with different thicknesses (0.5 mm, 0.8 mm and 1.0 mm) were prepared from three all-ceramic systems, In-Ceram Alumina (IC), IPS e.max Press (EM) and Katana (K). The colors of the samples were measured with a spectrophotometer and the color parameters (L*, a*, b*, ΔE) were calculated according to the CIE L*a*b* (Commission Internationale de L'Eclairage) color system before and after aging. The effects of aging on color parameters were statistically significant (p < 0.001), regardless of core thickness. For all systems, the CIE a* values increased as the thickness of the core increased. Conversely, such increases in core porcelain thickness were correlated with decreasing CIE L* and b* values. Core thickness had a statistically significant effect on color change among the groups. Different core thicknesses (from 1.0-0.5 mm) and artificial aging affected color stability of the all-ceramic materials tested.

Color enhancement and image defogging in HSI based on Retinex model

NASA Astrophysics Data System (ADS)

Gao, Han; Wei, Ping; Ke, Jun

2015-08-01

Retinex is a luminance perceptual algorithm based on color consistency. It has a good performance in color enhancement. But in some cases, the traditional Retinex algorithms, both Single-Scale Retinex(SSR) and Multi-Scale Retinex(MSR) in RGB color space, do not work well and will cause color deviation. To solve this problem, we present improved SSR and MSR algorithms. Compared to other Retinex algorithms, we implement Retinex algorithms in HSI(Hue, Saturation, Intensity) color space, and use a parameter αto improve quality of the image. Moreover, the algorithms presented in this paper has a good performance in image defogging. Contrasted with traditional Retinex algorithms, we use intensity channel to obtain reflection information of an image. The intensity channel is processed using a Gaussian center-surround image filter to get light information, which should be removed from intensity channel. After that, we subtract the light information from intensity channel to obtain the reflection image, which only includes the attribute of the objects in image. Using the reflection image and a parameter α, which is an arbitrary scale factor set manually, we improve the intensity channel, and complete the color enhancement. Our experiments show that this approach works well compared with existing methods for color enhancement. Besides a better performance in color deviation problem and image defogging, a visible improvement in the image quality for human contrast perception is also observed.

Kinetics of color development of peanuts during dry roasting using a batch roaster

USDA-ARS?s Scientific Manuscript database

The kinetics of color development during peanut roasting were investigated at roasting temperatures from 149 to 204 °C which produced Hunter L color values of 25 to 65. Preliminary and equivalent roasting trials were conducted using a batch roaster simulating the parameters of an industrial continuo...

When viewing natural scenes, do abnormal colors impact on spatial or temporal parameters of eye movements?

PubMed

Ho-Phuoc, Tien; Guyader, Nathalie; Landragin, Frédéric; Guérin-Dugué, Anne

2012-02-03

Since Treisman's theory, it has been generally accepted that color is an elementary feature that guides eye movements when looking at natural scenes. Hence, most computational models of visual attention predict eye movements using color as an important visual feature. In this paper, using experimental data, we show that color does not affect where observers look when viewing natural scene images. Neither colors nor abnormal colors modify observers' fixation locations when compared to the same scenes in grayscale. In the same way, we did not find any significant difference between the scanpaths under grayscale, color, or abnormal color viewing conditions. However, we observed a decrease in fixation duration for color and abnormal color, and this was particularly true at the beginning of scene exploration. Finally, we found that abnormal color modifies saccade amplitude distribution.

[Color stability of porcelain-fused-to-titanium restorations after repeated firings].

PubMed

Wu, Xiao-min; Zhou, Zheng

2004-08-01

To study the effect of repeated firings on color of porcelain-fused-to-titanium restorations. Twenty standard porcelain-fused-to-titanium specimens were made with Dentsply DETREY TiBond C3 and Dentaurum rematitan Til. Then they were fired 1, 2, 4, 7, and 10 times. Color measurement was done after each firing. Most of the color parameters had no significant difference after firing except for a* and Hab. All the color difference among groups were smaller than 1.0 (deltaE < 1.0). Repeated firings will not affect the color stability of porcelain-fused-to-titanium restorations.

Diagnosing synaesthesia with online colour pickers: maximising sensitivity and specificity.

PubMed

Rothen, Nicolas; Seth, Anil K; Witzel, Christoph; Ward, Jamie

2013-04-30

The most commonly used method for formally assessing grapheme-colour synaesthesia (i.e., experiencing colours in response to letter and/or number stimuli) involves selecting colours from a large colour palette on several occasions and measuring consistency of the colours selected. However, the ability to diagnose synaesthesia using this method depends on several factors that have not been directly contrasted. These include the type of colour space used (e.g., RGB, HSV, CIELUV, CIELAB) and different measures of consistency (e.g., city block and Euclidean distance in colour space). This study aims to find the most reliable way of diagnosing grapheme-colour synaesthesia based on maximising sensitivity (i.e., ability of a test to identify true synaesthetes) and specificity (i.e., ability of a test to identify true non-synaesthetes). We show, applying ROC (receiver operating characteristics) to binary classification of a large sample of self-declared synaesthetes and non-synaesthetes, that the consistency criterion (i.e., cut-off value) for diagnosing synaesthesia is considerably higher than the current standard in the field. We also show that methods based on perceptual CIELUV and CIELAB colour models (rather than RGB and HSV colour representations) and Euclidean distances offer an even greater sensitivity and specificity than most currently used measures. Together, these findings offer improved heuristics for the behavioural assessment of grapheme-colour synaesthesia. Copyright © 2013 Elsevier B.V. All rights reserved.

Modelling vehicle colour and pattern for multiple deployment environments

NASA Astrophysics Data System (ADS)

Liggins, Eric; Moorhead, Ian R.; Pearce, Daniel A.; Baker, Christopher J.; Serle, William P.

2016-10-01

Military land platforms are often deployed around the world in very different climate zones. Procuring vehicles in a large range of camouflage patterns and colour schemes is expensive and may limit the environments in which they can be effectively used. As such this paper reports a modelling approach for use in the optimisation and selection of a colour palette, to support operations in diverse environments and terrains. Three different techniques were considered based upon the differences between vehicle and background in L*a*b* colour space, to predict the optimum (initially single) colour to reduce the vehicle signature in the visible band. Calibrated digital imagery was used as backgrounds and a number of scenes were sampled. The three approaches used, and reported here are a) background averaging behind the vehicle b) background averaging in the area surrounding the vehicle and c) use of the spatial extension to CIE L*a*b*; S-CIELAB (Zhang and Wandell, Society for Information Display Symposium Technical Digest, vol. 27, pp. 731-734, 1996). Results are compared with natural scene colour statistics. The models used showed good agreement in the colour predictions for individual and multiple terrains or climate zones. A further development of the technique examines the effect of different patterns and colour combinations on the S-CIELAB spatial colour difference metric, when scaled for appropriate viewing ranges.

Effect of esthetic core shades on the final color of IPS Empress all-ceramic crowns.

PubMed

Azer, Shereen S; Ayash, Ghada M; Johnston, William M; Khalil, Moustafa F; Rosenstiel, Stephen F

2006-12-01

Clinically relevant assessment of all-ceramic crowns supported by esthetic composite resin foundations has not been evaluated with regard to color reproducibility. This in vitro study quantitatively evaluated the influence of different shades of composite resin foundations and resin cement on the final color of a leucite-reinforced all-ceramic material. A total of 128 disks were fabricated; 64 (20 x 1 mm) were made of all-ceramic material (IPS Empress) and 64 (20 x 4 mm) of 4 different shades composite resin (Tetric Ceram). The ceramic and composite resin disks were luted using 2 shades (A3 and Transparent) of resin cement (Variolink II). Color was measured using a colorimeter configured with a diffuse illumination/0-degree viewing geometry, and Commission Internationale de l'Eclairage (CIE) L( *)a( *)b( *) values were directly calculated. Descriptive statistical analysis was performed, and color differences (DeltaE) for the average L( *), a( *) and b( *) color parameters were calculated. Repeated measures analysis of variance (ANOVA) was used to compare mean values and SDs between the different color combinations (alpha=.05). The CIE L( *)a( *)b( *) color coordinate values showed no significant differences for variation in color parameters due to the effect of the different composite resin shades (P=.24) or cement shades (P=.12). The mean color difference (DeltaE) value between the groups was 0.8. Within the limitations of this study, the use of different shades for composite resin cores and resin cements presented no statistically significant effect on the final color of IPS Empress all-ceramic material.

Safety sign designs for children by considering effect of the colors preferences: A case study

NASA Astrophysics Data System (ADS)

Iftadi, Irwan; Nugraha, Dian Cahya; Jauhari, Wakhid Ahmad

2018-02-01

Color has become a major consideration in ergonomics. Color conveys a message and it is an important element in safety signs. The importance of colors usage in safety sign designs makes the colors research into one of the things that must be done before designing them. So far, research in the related field only focused on the adult's perspective without involving children's perspective in designing the safety signs. This paper aims to find out how children's perception towards colors affects the safety sign designs. This study consist of eight sections which are literature study, direct observation, determining referents and other parameters, determining research respondents, making the booklet, assessing the colors preferences, determining the design's parameter value and creating the safety sign designs. Limitation of the research are the objects are the students with the age of 10 - 11 years old in Grade IV and then the research is conducted in the school day and hours that apply to the school. Chi square test and odds ratio are employed to assess the colors preferences. Twelve safety sign designs are proposed by considering the children's colors perception. The designs are grouped into three types of sign which are Mandatory Action Sign, Warning Sign and Prohibition Sign. Six colors are used to draw the safety signs i.e. red, orange, yellow, green, blue and black. On the basis of the study, it is concluded that the colors that often appears in safety signs is green with the percentage of 75% and that rarely appears is red with the percentage of 8.33%.

[Natural selection associated with color vision defects in some population groups of Eurasia].

PubMed

Evsiukov, A N

2014-01-01

Fitness coefficients and other quantitative parameters of selection associated with the generalized color blindness gene CB+ were obtained for three ethnogeographic population groups, including Belarusians from Belarus, ethnic populations of the Volga-Ural region, and ethnic populations of Siberia and the Far East of Russia. All abnormalities encoded by the OPN1LW and OPN1MW loci were treated as deviations from normal color perception. Coefficients were estimated from an approximation of the observed CB+ frequency distributions to the theoretical stationary distribution for the Wright island model. This model takes into account the pressure of migrations, selection, and random genetic drift, while the selection parameters are represented in the form of the distribution parameters. In the populations of Siberia and Far East, directional selection in favor of normal color vision and the corresponding allele CB- was observed. In the Belarusian and ethnic populations of the Volga-Ural region, stabilizing selection was observed. The selection intensity constituted 0.03 in the Belarusian; 0.22 in the ethnic populations of the Volga-Ural region; and 0.24 in ethnic populations of Siberia and Far East.

Real-time color change monitoring of apple slices using image processing during intermittent microwave convective drying.

PubMed

Aghilinategh, Nahid; Rafiee, Shahin; Hosseinpour, Soleiman; Omid, Mahmoud; Mohtasebi, Seyed Saeid

2016-10-01

An intermittent microwave convective drying method combined with a real-time computer vision technique was employed to detect the effect of drying parameters on color properties of apple slices. The experiments were performed at air temperature of 40 to 80℃, air velocities of 1-2 m/s, microwave powers of 200-600 W, and pulse ratios (PRs) of 2-6. Drying rate and drying time varied from 0.014 to 0.000001 min -1 and 27 to 244 min, respectively. The normalized lightness values had ascending and descending parabolic trends with decrease in product moisture content. With descending dimensionless moisture content, redness, yellowness, color change, hue angle, and chroma were enlarged. The normalized redness values changed from -4 to 3. Models relating drying parameters with drying time, drying rate, and lightness were obtained and found to be significant (P < 0.01). Results indicated that microwave power and PRs had more influence on lightness and color change than other parameters. © The Author(s) 2016.

Color distribution of a shade guide in the value, chroma, and hue scale.

PubMed

Ahn, Jin-Soo; Lee, Yong-Keun

2008-07-01

Shade tabs in a shade guide are matched to teeth in the order of value, hue, and chroma; therefore, information on the distribution of shade tabs is essential for clinical application of a shade guide. However, there is limited information on the color distribution as sorted by these 3 parameters of a recently introduced shade guide. The purposes of this study were to determine the color distributions of tabs from a shade guide in the value (CIE L*), chroma (C*(ab)), and hue scale, and to determine the distribution of step intervals between adjacent tabs by value and chroma. The color of shade tabs (n=29) from a shade guide (Vitapan 3D-Master) was measured to determine the distribution of shade tabs by the value, chroma, hue angle, and CIE a* and b* values. The distribution of the ratios of the value and the chroma of each tab, when compared with the lowest value tab or the lowest chroma tab, was also determined. The data for each color parameter were analyzed by a 3-way ANOVA with the factors of value, chroma, and hue designations of the tabs (alpha=.05). The value, chroma, hue angle, and CIE a* and b* values were influenced by the value, chroma, and hue designations of shade tabs (P<.001). The distributions of the chroma of the tabs within the same value group were relatively ordered, but the values of different value groups overlapped in several instances. Distributions for the CIE a* and b* values reflected the chroma designations in each value group. In the same value group, L, M, and R hue designations corresponded with the manufacturer's stated hue, such as a yellow hue for the L designation and a red hue for the R designation. The distance in the value and chroma scales between adjacent tabs was not uniform. The color distribution of the Vitapan 3D-Master shade guide was more ordered than previously reported color distributions of other, traditional shade guides. However, the interval in the color parameters between adjacent tabs was not uniform; therefore, shade tabs spaced equally, according to the color parameters, should be studied based on the observer's response data.

An approach of characterizing the degree of spatial color mixture

NASA Astrophysics Data System (ADS)

Chu, Miao; Tian, Shaohui

2017-07-01

The digital camouflage technology arranges different color mosaics according to a certain rules, compared with traditional camouflage, it has more outstanding results deal with different distance reconnaissance. The better result of digital camouflage is mainly attributed to spatial color mixture, and is also a key factor to improve digital camouflage design. However, the research of space color mixture is relatively lack, cannot provide inadequate support for digital camouflage design. Therefore, according to the process of spatial color mixture, this paper proposes an effective parameter, spatial-color-mixture ratio, to characterize the degree of spatial color mixture. The experimental results show that spatial-color-mixture ratio is feasible and effective in practice, which could provide a new direction for further research on digital camouflage.

Calculation of evapotranspiration using color-infrared photography. [remote sensing in Arizona

NASA Technical Reports Server (NTRS)

Jones, J. E.

1977-01-01

Data from 38 color-infrared photographic missions flown during a five year period over the Gila River Phreatophyte Project in southeastern Arizona were analyzed to determine the possibility of identifying and measuring vegetative parameters and their associated hydrologic variables by spectral analysis of the photographs. The derived spectra equations are discussed, and a table of 24 statistical parameters describing the spectral and hydrologic variables is included.

[Colorimetric investigation of normal tongue and lip colors from 516 healthy adults by visible reflection spectrum].

PubMed

Zeng, Chang-chun; Yang, Li; Xu, Ying; Liu, Pei-pei; Guo, Shi-jun; Liu, Song-hao

2011-09-01

Using the data from normal tongue and lip colors of normal people which were collected by the visible reflection spectrum, we analyzed the colorimetric parameters of tongue and lip colors. In this study, 516 healthy students aging from 19 to 26 from the colleges and universities of Guangdong Province of China were taken as research subjects. After collecting the data of tongue and lip colors of the 516 subjects using visible reflectance spectroscopy, CIE XYZ tristimulus values as defined by the International Commission on Illumination in 1964 were calculated, and the colorimetric parameters of the normal tongue and lip colors were obtained, such as the CIE 1964 chromaticity coordinate, brightness, dominant wavelength and excitation purity. The results of CIE 1964 chromaticity diagram calculated on the visible reflection spectrum showed that the normal tongue color chromaticity coordinate x(10) was 0.341 3±0.008 5 and y(10) was 0.332 6±0.005 1, and the normal lip color chromaticity coordinate x(10) was 0.357 7±0.009 2 and y(10) was 0.338 3±0.005 7; the brightness Y values of the normal tongue color and lip colors were 17.96±3.78 and 19.78±3.72, the dominant wavelength values of the normal tongue color and lip color were (626.3±51.6) nm and (600.4±18.2) nm, and the excitation purity values of the normal tongue color and lip color were 0.083±0.031 and 0.144±0.036, respectively. Application of the visible reflection spectrum is a standard way to collect colorimetric data for inspection of the complexion. The investigation of chromaticity coordinates, brightness, dominant wavelength and excitation purity of the normal tongue and lip colors may offer the basic reference for diagnosing morbid complexion on the tongue and lip colors in traditional Chinese medicine.

Minimization of operational impacts on spectrophotometer color measurements for cotton

USDA-ARS?s Scientific Manuscript database

A key cotton quality and processing property that is gaining increasing importance is the color of the cotton. Cotton fiber in the U.S. is classified for color using the Uster® High Volume Instrument (HVI), using the parameters Rd and +b. Rd and +b are specific to cotton fiber and are not typical ...

Fiber sample presentation system for spectrophotometer cotton fiber color measurements

USDA-ARS?s Scientific Manuscript database

The Uster® High Volume Instrument (HVI) is used to class U.S. cotton for fiber color, yielding the industry accepted, cotton-specific color parameters Rd and +b. The HVI examines a 9 square inch fiber sample, and it is also used to test large AMS standard cotton “biscuits” or rectangles. Much inte...

Predicting minimum uncertainties in the inversion of ocean color geophysical parameters based on Cramer-Rao bounds.

PubMed

Jay, Sylvain; Guillaume, Mireille; Chami, Malik; Minghelli, Audrey; Deville, Yannick; Lafrance, Bruno; Serfaty, Véronique

2018-01-22

We present an analytical approach based on Cramer-Rao Bounds (CRBs) to investigate the uncertainties in estimated ocean color parameters resulting from the propagation of uncertainties in the bio-optical reflectance modeling through the inversion process. Based on given bio-optical and noise probabilistic models, CRBs can be computed efficiently for any set of ocean color parameters and any sensor configuration, directly providing the minimum estimation variance that can be possibly attained by any unbiased estimator of any targeted parameter. Here, CRBs are explicitly developed using (1) two water reflectance models corresponding to deep and shallow waters, resp., and (2) four probabilistic models describing the environmental noises observed within four Sentinel-2 MSI, HICO, Sentinel-3 OLCI and MODIS images, resp. For both deep and shallow waters, CRBs are shown to be consistent with the experimental estimation variances obtained using two published remote-sensing methods, while not requiring one to perform any inversion. CRBs are also used to investigate to what extent perfect a priori knowledge on one or several geophysical parameters can improve the estimation of remaining unknown parameters. For example, using pre-existing knowledge of bathymetry (e.g., derived from LiDAR) within the inversion is shown to greatly improve the retrieval of bottom cover for shallow waters. Finally, CRBs are shown to provide valuable information on the best estimation performances that may be achieved with the MSI, HICO, OLCI and MODIS configurations for a variety of oceanic, coastal and inland waters. CRBs are thus demonstrated to be an informative and efficient tool to characterize minimum uncertainties in inverted ocean color geophysical parameters.

Rec.2100 color gamut revelation using spectrally ultranarrow emitters

NASA Astrophysics Data System (ADS)

Genc, Sinan; Uguz, Mustafa; Yilmaz, Osman; Mutlugun, Evren

2017-11-01

We theoretically simulate the performance of ultranarrow emitters for the first time to achieve record high coverage for the International Telecommunication Union Radiocommunication Sector BT.2100 (Rec.2100) and National Television System Committee (NTSC) color gamut. Our results, employing more than 130-m parameter sets, include the investigation into peak emission wavelength and full width at half maximum (FWHM) values for three primaries that show ultranarrow emitters, i.e., nanoplatelets are potentially promising materials to fully cover the Rec.2100 color gamut. Using ultranarrow emitters having FWHM as low as 6 nm can provide the ability to attain 99.7% coverage area of the Rec.2100 color gamut as well as increasing the NTSC triangle to 133.7% with full coverage. The parameter set that provides possibility to fully reach Rec.2100 also has been shown to match with D65 white light by making use of the correct combination of those three primaries. Furthermore, we investigate the effect of the fourth color component on the CIE 1931 color space without sacrificing the achieved coverage percentages. The investigation into the fourth color component, cyan, is shown for the first time to enhance the Rec.2100 gamut area to 127.7% with 99.9% coverage. The fourth color component also provides an NTSC coverage ratio of 171.5%. The investigation into the potential of emitters with ultranarrow emission bandwidth holds great promise for future display applications.

Trihydroxybenzoic acid glucoside as a global skin color modulator and photo-protectant

PubMed Central

Chajra, Hanane; Redziniak, Gérard; Auriol, Daniel; Schweikert, Kuno; Lefevre, Fabrice

2015-01-01

Background 3,4,5-Trihydroxybenzoic acid glucoside (THBG), a molecule produced by an original biocatalysis-based technology, was assessed in this study with respect to its skin photoprotective capacity and its skin color control property on Asian-type skin at a clinical level and on skin explant culture models. Methods The double-blinded clinical study was done in comparison to a vehicle by the determination of objective color parameters thanks to recognized quantitative and qualitative analysis tools, including Chroma-Meter, VISIA-CR™, and SIAscope™. Determination of L* (brightness), a* and b* (green–red and blue–yellow chromaticity coordinates), individual typology angle, and C* (chroma) and h* (hue angle) parameters using a Chroma-Meter demonstrated that THBG is able to modify skin color while quantification of ultraviolet (UV) spots by VISIA-CR™ confirmed its photoprotective effect. The mechanism of action of THBG molecule was determined using explant skin culture model coupled to histological analysis (epidermis melanin content staining). Results We have demonstrated that THBG was able to modulate significantly several critical parameters involved in skin color control such as L* (brightness), a* (redness), individual typology angle (pigmentation), and hue angle (yellowness in this study), whereas no modification occurs on b* and C* parameters. We have demonstrated using histological staining that THBG decrease epidermis melanin content under unirradiated and irradiated condition. We also confirmed that THBG molecule is not a sunscreen agent. Conclusion This study demonstrated that THBG controls skin tone via the inhibition of melanin synthesis as well as the modulation of skin brightness, yellowness, and redness. PMID:26648748

Real-time Supervised Detection of Pink Areas in Dermoscopic Images of Melanoma: Importance of Color Shades, Texture and Location

PubMed Central

Kaur, Ravneet; Albano, Peter P.; Cole, Justin G.; Hagerty, Jason; LeAnder, Robert W.; Moss, Randy H.; Stoecker, William V.

2015-01-01

Background/Purpose Early detection of malignant melanoma is an important public health challenge. In the USA, dermatologists are seeing more melanomas at an early stage, before classic melanoma features have become apparent. Pink color is a feature of these early melanomas. If rapid and accurate automatic detection of pink color in these melanomas could be accomplished, there could be significant public health benefits. Methods Detection of three shades of pink (light pink, dark pink, and orange pink) was accomplished using color analysis techniques in five color planes (red, green, blue, hue and saturation). Color shade analysis was performed using a logistic regression model trained with an image set of 60 dermoscopic images of melanoma that contained pink areas. Detected pink shade areas were further analyzed with regard to the location within the lesion, average color parameters over the detected areas, and histogram texture features. Results Logistic regression analysis of a separate set of 128 melanomas and 128 benign images resulted in up to 87.9% accuracy in discriminating melanoma from benign lesions measured using area under the receiver operating characteristic curve. The accuracy in this model decreased when parameters for individual shades, texture, or shade location within the lesion were omitted. Conclusion Texture, color, and lesion location analysis applied to multiple shades of pink can assist in melanoma detection. When any of these three details: color location, shade analysis, or texture analysis were omitted from the model, accuracy in separating melanoma from benign lesions was lowered. Separation of colors into shades and further details that enhance the characterization of these color shades are needed for optimal discrimination of melanoma from benign lesions. PMID:25809473

Real-time supervised detection of pink areas in dermoscopic images of melanoma: importance of color shades, texture and location.

PubMed

Kaur, R; Albano, P P; Cole, J G; Hagerty, J; LeAnder, R W; Moss, R H; Stoecker, W V

2015-11-01

Early detection of malignant melanoma is an important public health challenge. In the USA, dermatologists are seeing more melanomas at an early stage, before classic melanoma features have become apparent. Pink color is a feature of these early melanomas. If rapid and accurate automatic detection of pink color in these melanomas could be accomplished, there could be significant public health benefits. Detection of three shades of pink (light pink, dark pink, and orange pink) was accomplished using color analysis techniques in five color planes (red, green, blue, hue, and saturation). Color shade analysis was performed using a logistic regression model trained with an image set of 60 dermoscopic images of melanoma that contained pink areas. Detected pink shade areas were further analyzed with regard to the location within the lesion, average color parameters over the detected areas, and histogram texture features. Logistic regression analysis of a separate set of 128 melanomas and 128 benign images resulted in up to 87.9% accuracy in discriminating melanoma from benign lesions measured using area under the receiver operating characteristic curve. The accuracy in this model decreased when parameters for individual shades, texture, or shade location within the lesion were omitted. Texture, color, and lesion location analysis applied to multiple shades of pink can assist in melanoma detection. When any of these three details: color location, shade analysis, or texture analysis were omitted from the model, accuracy in separating melanoma from benign lesions was lowered. Separation of colors into shades and further details that enhance the characterization of these color shades are needed for optimal discrimination of melanoma from benign lesions. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

An ecological valence theory of human color preference.

PubMed

Palmer, Stephen E; Schloss, Karen B

2010-05-11

Color preference is an important aspect of visual experience, but little is known about why people in general like some colors more than others. Previous research suggested explanations based on biological adaptations [Hurlbert AC, Ling YL (2007) Curr Biol 17:623-625] and color-emotions [Ou L-C, Luo MR, Woodcock A, Wright A (2004) Color Res Appl 29:381-389]. In this article we articulate an ecological valence theory in which color preferences arise from people's average affective responses to color-associated objects. An empirical test provides strong support for this theory: People like colors strongly associated with objects they like (e.g., blues with clear skies and clean water) and dislike colors strongly associated with objects they dislike (e.g., browns with feces and rotten food). Relative to alternative theories, the ecological valence theory both fits the data better (even with fewer free parameters) and provides a more plausible, comprehensive causal explanation of color preferences.

Exogenous Applications of Brassinosteroids Improve Color of Red Table Grape (Vitis vinifera L. Cv. "Redglobe") Berries.

PubMed

Vergara, Alexis E; Díaz, Katy; Carvajal, Rodrigo; Espinoza, Luis; Alcalde, José A; Pérez-Donoso, Alonso G

2018-01-01

Color and other quality parameters of "Redglobe" grape ( Vitis vinifera L.) berries were evaluated after treatment with brassinosteroid (BR) analogs. Three BRs analogs (24-epibrassinolide, Triol, or Lactone) were applied at three concentrations (0.0, 0.4, or 0.8 mg⋅L -1 ), at the onset of veraison. A commercial formulation (B-2000 ® ) was also applied, at a recommended rate of 0.06 mg⋅L -1 . The tested BR analogs were effective improving berry color (evaluated as color index for red grapes, CIRG), increasing the levels of soluble solids and anthocyanins, and changing the types of anthocyanins present without altering other quality and yield parameters. The effects of BR analogs on color enhancement could be explained by an increase in soluble solids content and/or anthocyanin content. Treatment with 24-epibrassinolide (at 0.4 mg⋅L -1 ) or the commercial formulation tended to favor the production of dihydroxylated anthocyanins, which are responsible for the red and pink colors of grape berries. Results indicate that the use of BRs constitutes a potential tool in the production of table grapes. This is the first report of this enhancement effect in a productive context.

Exogenous Applications of Brassinosteroids Improve Color of Red Table Grape (Vitis vinifera L. Cv. “Redglobe”) Berries

PubMed Central

Vergara, Alexis E.; Díaz, Katy; Carvajal, Rodrigo; Espinoza, Luis; Alcalde, José A.; Pérez-Donoso, Alonso G.

2018-01-01

Color and other quality parameters of “Redglobe” grape (Vitis vinifera L.) berries were evaluated after treatment with brassinosteroid (BR) analogs. Three BRs analogs (24-epibrassinolide, Triol, or Lactone) were applied at three concentrations (0.0, 0.4, or 0.8 mg⋅L-1), at the onset of veraison. A commercial formulation (B-2000®) was also applied, at a recommended rate of 0.06 mg⋅L-1. The tested BR analogs were effective improving berry color (evaluated as color index for red grapes, CIRG), increasing the levels of soluble solids and anthocyanins, and changing the types of anthocyanins present without altering other quality and yield parameters. The effects of BR analogs on color enhancement could be explained by an increase in soluble solids content and/or anthocyanin content. Treatment with 24-epibrassinolide (at 0.4 mg⋅L-1) or the commercial formulation tended to favor the production of dihydroxylated anthocyanins, which are responsible for the red and pink colors of grape berries. Results indicate that the use of BRs constitutes a potential tool in the production of table grapes. This is the first report of this enhancement effect in a productive context. PMID:29681907

Color image cryptosystem using Fresnel diffraction and phase modulation in an expanded fractional Fourier transform domain

NASA Astrophysics Data System (ADS)

Chen, Hang; Liu, Zhengjun; Chen, Qi; Blondel, Walter; Varis, Pierre

2018-05-01

In this letter, what we believe is a new technique for optical color image encryption by using Fresnel diffraction and a phase modulation in an extended fractional Fourier transform domain is proposed. Different from the RGB component separation based method, the color image is converted into one component by improved Chirikov mapping. The encryption system is addressed with Fresnel diffraction and phase modulation. A pair of lenses is placed into the fractional Fourier transform system for the modulation of beam propagation. The structure parameters of the optical system and parameters in Chirikov mapping serve as extra keys. Some numerical simulations are given to test the validity of the proposed cryptosystem.

Effects of heating method and conditions on the evaporation rate and quality attributes of black mulberry (Morus nigra) juice concentrate.

PubMed

Fazaeli, Mahboubeh; Hojjatpanah, Ghazale; Emam-Djomeh, Zahra

2013-02-01

Black mulberry juice was concentrated by different heating methods, including conventional heating and microwave heating, at different operational pressures (7.3, 38.5 and 100 kPa). The effects of each method on evaporation rate, quality attributes of concentrated juice were investigated. The final juice concentration of 42° Brix was achieved in 140, 120, and 95 min at 100, 38.5, and 7.3 kPa respectively by using a rotary evaporator. Applying microwave energy decreased required times to 115, 95, and 60 min. The changes in color, anthocyanin content during the concentration processes were investigated. Hunter parameters (L, a, and b) were measured to estimate the intensity of color loss. All Hunter color parameters decreased with time. Results showed that the degradation of color and consequently anthocyanins, was more pronounced in rotary evaporation compared to microwave heating method.

Evaluation of reliability and validity of three dental color-matching devices.

PubMed

Tsiliagkou, Aikaterini; Diamantopoulou, Sofia; Papazoglou, Efstratios; Kakaboura, Afrodite

2016-01-01

To assess the repeatability and accuracy of three dental color-matching devices under standardized and freehand measurement conditions. Two shade guides (Vita Classical A1-D4, Vita; and Vita Toothguide 3D-Master, Vita), and three color-matching devices (Easyshade, Vita; SpectroShade, MHT Optic Research; and ShadeVision, X-Rite) were used. Five shade tabs were selected from the Vita Classical A1-D4 (A2, A3.5, B1, C4, D3), and five from the Vita Toothguide 3D-Master (1M1, 2R1.5, 3M2, 4L2.5, 5M3) shade guides. Each shade tab was recorded 15 continuous, repeated times with each device under two different measurement conditions (standardized, and freehand). Both qualitative (color shade) and quantitative (L, a, and b) color characteristics were recorded. The color difference (ΔE) of each recorded value with the known values of the shade tab was calculated. The repeatability of each device was evaluated by the coefficient of variance. The accuracy of each device was determined by comparing the recorded values with the known values of the reference shade tab (one sample t test; α = 0.05). The agreement between the recorded shade and the reference shade tab was calculated. The influence of the parameters (devices and conditions) on the parameter ΔE was investigated (two-way ANOVA). Comparison of the devices was performed with Bonferroni pairwise post-hoc analysis. Under standardized conditions, repeatability of all three devices was very good, except for ShadeVision with Vita Classical A1-D4. Accuracy ranged from good to fair, depending on the device and the shade guide. Under freehand conditions, repeatability and accuracy for Easyshade and ShadeVision were negatively influenced, but not for SpectroShade, regardless of the shade guide. Based on the total of the color parameters assessed per device, SpectroShade was the most reliable of the three color-matching devices studied.

Medical color displays and their color calibration: investigations of various calibration methods, tools, and potential improvement in color difference ΔE

NASA Astrophysics Data System (ADS)

Roehrig, Hans; Hashmi, Syed F.; Dallas, William J.; Krupinski, Elizabeth A.; Rehm, Kelly; Fan, Jiahua

2010-08-01

Our laboratory has investigated the efficacy of a suite of color calibration and monitor profiling packages which employ a variety of color measurement sensors. Each of the methods computes gamma correction tables for the red, green and blue color channels of a monitor that attempt to: a) match a desired luminance range and tone reproduction curve; and b) maintain a target neutral point across the range of grey values. All of the methods examined here produce International Color Consortium (ICC) profiles that describe the color rendering capabilities of the monitor after calibration. Color profiles incorporate a transfer matrix that establishes the relationship between RGB driving levels and the International Commission on Illumination (CIE) XYZ (tristimulus) values of the resulting on-screen color; the matrix is developed by displaying color patches of known RGB values on the monitor and measuring the tristimulus values with a sensor. The number and chromatic distribution of color patches varies across methods and is usually not under user control. In this work we examine the effect of employing differing calibration and profiling methods on rendition of color images. A series of color patches encoded in sRGB color space were presented on the monitor using color-management software that utilized the ICC profile produced by each method. The patches were displayed on the calibrated monitor and measured with a Minolta CS200 colorimeter. Differences in intended and achieved luminance and chromaticity were computed using the CIE DE2000 color-difference metric, in which a value of ΔE = 1 is generally considered to be approximately one just noticeable difference (JND) in color. We observed between one and 17 JND's for individual colors, depending on calibration method and target. As an extension of this fundamental work1, we further improved our calibration method by defining concrete calibration parameters for the display, using the NEC wide gamut puck, and making sure that those calibration parameters did conform, with the help of a state of the art Spectroradiometer, PR670. As a result of this addition of the PR670, and also an in-house developed method of profiling and characterization, it appears that there was much improvement in ΔE, the color difference.

Use of stereo vision and 24-bit false-color imagery to enhance visualization of multimodal confocal images

NASA Astrophysics Data System (ADS)

Beltrame, Francesco; Diaspro, Alberto; Fato, Marco; Martin, I.; Ramoino, Paola; Sobel, Irwin E.

1995-03-01

Confocal microscopy systems can be linked to 3D data oriented devices for the interactive navigation of the operator through a 3D object space. Sometimes, such environments are named `virtual reality' or `augmented reality' systems. We consider optical confocal laser scanning microscopy images, in fluorescence with various excitations and emissions, and versus time The aim of our study has been the quantitative spatial analysis of confocal data using the false-color composition technique. Starting from three 2D confocal fluorescent images at the same slice location in a given biological specimen, a new single image representation of all three parameters has been generated by the false-color technique on a HP 9000/735 workstation, connected to the confocal microscope. The color composite result of the mapping of the three parameters is displayed using a resolution of 24 bits per pixel. The operator may independently vary the mix of each of the three components in the false-color composite via three (R, G, B) mixing sliders. Furthermore, by using the pixel data in the three fluorescent component images, a 3D space containing the density distribution of these three parameters has been constructed. The histogram has been displayed in stereo: it can be used for clustering purposes from the operator, through an original thresholding algorithm.

[Influence of all-ceramic and porcelain-fused-to-metal restorations on peri-implant gingival discoloration:a spectrophotometric comparison].

PubMed

Peng, Min; Fei, Wei; Mandana, Hosseini; Klaus, Gotfredsen

2013-04-01

To compare the gingival discoloration of implant supported all-ceramic and porcelain-fused-to-metal (PFM) restorations in anterior maxillary region by spectrophotometric evaluation. Eighteen patients with 29 implant-supported single crowns (11 all-ceramic restorations, 9 PFM restorations with titanium abutment and 9 PFM restorations with golden alloy abutment) in anterior maxillary area were recruited. The color difference between peri-implant gingiva and contra-lateral/neighboring mucosa was assessed using a spectrophotometer in CIELab coordinates. Subjective gingival discoloration scores were evaluated by clinician. SPSS17.0 software package was used to analyze the data. There was no significant difference between all-ceramic group (3.4±1.8) and PFM group (4.9±3.4) spectrophotometrically. No significant difference was found between all-ceramic restorations and PFM restorations with titanium abutment (3.5±2.5), and no significant difference was found between PFM restorations with titanium abutment and PFM restorations with gold alloy abutment (6.3±3.8) either. There was, however, significant difference between all-ceramic restorations and PFM restorations with gold alloy abutment (P=0.037). There was no significant difference between all-ceramic group and PFM group regarding the clinical gingival discoloration score (GDS), and this gingival discoloration score was found to have significant correlation with the spectrophotometric evaluation (rs=0.426, P=0.021). There is no significant difference between all-ceramic group and PFM group as regard to both spectrophotometric and clinical evaluation of gingival discoloration, but the PFM restorations with gold alloy abutment induce significantly higher discoloration than all-ceramic restorations.

Low-temperature atmospheric pressure plasma enhanced tooth whitening: the next-generation technology.

PubMed

Claiborne, D; McCombs, G; Lemaster, M; Akman, M A; Laroussi, M

2014-05-01

To evaluate the safety and effectiveness of the plasma pencil (PP) device in conjunction with H2 O2 gel. The purpose of this study was to determine whether LTAPP delivered using the PP would enhance the tooth-whitening process while causing no thermal threat. The study consisted of thirty extracted human teeth that were randomized into two groups: Group I received LTAPP plus 36% H2 O2 gel at 10, 15 and 20 min and Group II received 36% H2 O2 gel only at the same time intervals. Tooth surface temperature was measured periodically throughout the experiment using a non-contact thermometer. Digital photographs were taken pre- and post-treatment and transferred to Adobe Photoshop for comparison, using the CIELAB Color Value System. Only L* (lightness) values were evaluated in this study. Data were analysed using descriptive statistics and t-test at the 0.05 level. The results revealed a statistically significant difference in mean CIE L* values after exposure to LTAPP plus 36% H2 O2 gel, compared with 36% H2 O2 only, in the 10- and 20-min groups (P = 0.0003 and 0.0103, respectively). The temperature in both treatment groups remained under 80°F throughout the study, which is below the thermal threat for vital tooth bleaching. Utilizing PP device in conjunction with 36% H2 O2 safely accelerates and enhances the tooth-whitening process. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Vessel discoloration detection in malarial retinopathy

NASA Astrophysics Data System (ADS)

Agurto, C.; Nemeth, S.; Barriga, S.; Soliz, P.; MacCormick, I.; Taylor, T.; Harding, S.; Lewallen, S.; Joshi, V.

2016-03-01

Cerebral malaria (CM) is a life-threatening clinical syndrome associated with malarial infection. It affects approximately 200 million people, mostly sub-Saharan African children under five years of age. Malarial retinopathy (MR) is a condition in which lesions such as whitening and vessel discoloration that are highly specific to CM appear in the retina. Other unrelated diseases can present with symptoms similar to CM, therefore the exact nature of the clinical symptoms must be ascertained in order to avoid misdiagnosis, which can lead to inappropriate treatment and, potentially, death. In this paper we outline the first system to detect the presence of discolored vessels associated with MR as a means to improve the CM diagnosis. We modified and improved our previous vessel segmentation algorithm by incorporating the `a' channel of the CIELab color space and noise reduction. We then divided the segmented vasculature into vessel segments and extracted features at the wall and in the centerline of the segment. Finally, we used a regression classifier to sort the segments into discolored and not-discolored vessel classes. By counting the abnormal vessel segments in each image, we were able to divide the analyzed images into two groups: normal and presence of vessel discoloration due to MR. We achieved an accuracy of 85% with sensitivity of 94% and specificity of 67%. In clinical practice, this algorithm would be combined with other MR retinal pathology detection algorithms. Therefore, a high specificity can be achieved. By choosing a different operating point in the ROC curve, our system achieved sensitivity of 67% with specificity of 100%.

Continuous hierarchical slope-aspect color display for parametric surfaces

NASA Technical Reports Server (NTRS)

Moellering, Harold J. (Inventor); Kimerling, A. Jon (Inventor)

1994-01-01

A method for generating an image of a parametric surface, such as the aspect of terrain which maximizes color contrast to permit easy discrimination of the magnitude, ranges, intervals or classes of a surface parameter while making it easy for the user to visualize the form of the surface, such as a landscape. The four pole colors of the opponent process color theory are utilized to represent intervals or classes at 90 degree angles. The color perceived as having maximum measured luminance is selected to portray the color having an azimuth of an assumed light source and the color showing minimum measured luminance portrays the diametrically opposite azimuth. The 90 degree intermediate azimuths are portrayed by unique colors of intermediate measured luminance, such as red and green. Colors between these four pole colors are used which are perceived as mixtures or combinations of their bounding colors and are arranged progressively between their bounding colors to have perceived proportional mixtures of the bounding colors which are proportional to the interval's angular distance from its bounding colors.

A design study for an advanced ocean color scanner system. [spaceborne equipment

NASA Technical Reports Server (NTRS)

Kim, H. H.; Fraser, R. S.; Thompson, L. L.; Bahethi, O.

1980-01-01

Along with a colorimetric data analysis scheme, the instrumental parameters which need to be optimized in future spaceborne ocean color scanner systems are outlined. With regard to assessing atmospheric effects from ocean colorimetry, attention is given to computing size parameters of the aerosols in the atmosphere, total optical depth measurement, and the aerosol optical thickness. It is suggested that sensors based on the use of linear array technology will meet hardware objectives.

Reducing LANDSAT data to parameters with physical significance and signature extension: A view of LANDSAT capabilities

NASA Technical Reports Server (NTRS)

Salmon-Drexler, B. C.

1977-01-01

The premise is the LANDSAT is capable of sensing only a few physical parameters. Much of the contrast provided in LANDSAT data is provided by differences in vegetation cover. Although dominant, vegetation is not the only physical parameter that can be detected with LANDSAT; a ratio of MSS Channel 5 to MSS Channel 4 (R5,4), two visible channels, separates materials by color hue. Additional information is attained by the addition of MSS channels 5 and 4 to approximate brightness, permitting separation of materials by color value. Other spectral combinations may provide correlations with these physical parameters or new ones. An iron absorption in the infrared can also be recognized in LANDSAT data when iron content is present in sufficient percentages, Although by color, limonite-rich soils are distinctive as bright yellow, they are not unique in the R5,4. A fairly strong iron absorption is present in the infrared band MSS Channel 7 for these soils, although the wideband configuration of LANDSAT is not optimal for its enhancement and the effects of vegetation often obscure it.

Variation of thermal parameters in two different color morphs of a diurnal poison toad, Melanophryniscus rubriventris (Anura: Bufonidae).

PubMed

Sanabria, Eduardo A; Vaira, Marcos; Quiroga, Lorena B; Akmentins, Mauricio S; Pereyra, Laura C

2014-04-01

We study the variation in thermal parameters in two contrasting populations Yungas Redbelly Toads (Melanophryniscus rubriventris) with different discrete color phenotypes comparing field body temperatures, critical thermal maximum and heating rates. We found significant differences in field body temperatures of the different morphs. Temperatures were higher in toads with a high extent of dorsal melanization. No variation was registered in operative temperatures between the study locations at the moment of capture and processing. Critical thermal maximum of toads was positively related with the extent of dorsal melanization. Furthermore, we founded significant differences in heating rates between morphs, where individuals with a high extent of dorsal melanization showed greater heating rates than toads with lower dorsal melanization. The color pattern-thermal parameter relationship observed may influence the activity patterns and body size of individuals. Body temperature is a modulator of physiological and behavioral functions in amphibians, influencing daily and seasonal activity, locomotor performance, digestion rate and growth rate. It is possible that some growth constraints may arise due to the relationship of color pattern-metabolism allowing different morphs to attain similar sizes at different locations instead of body-size clines. Copyright © 2014. Published by Elsevier Ltd.

Effect of γ-irradiation on the physicochemical and sensory properties of hazelnuts ( Corylus avellana L.)

NASA Astrophysics Data System (ADS)

Mexis, S. F.; Kontominas, M. G.

2009-06-01

The present study evaluated the quality of hazelnuts as a function of irradiation dose to determine dose levels causing minimal undesirable changes to hazelnuts. Physicochemical (color, peroxide value (PV), hexanal content, fatty acid composition and volatile compounds) and sensory (color, texture, odor and taste) properties were determined. Results showed a twenty fold increase in peroxide value and twenty-eight fold increase in hexanal content after irradiation at a dose of 7 kGy. An increase was also observed in saturated fatty acids (10%-23%) with a parallel decrease in unsaturated fatty acids (90-77%). Volatile compounds such as ketones, alkanes, alcohols, aldehydes, furans, aromatic hydrocarbons, bicyclic monoterpenes and acids were produced mostly comprising secondary oxidation products of hazelnut lipids after irradiation. Color parameter b* increased ( p<0.05) after irradiation at a dose of ⩾5 kGy, while color parameters L* and a* remained unchanged by irradiation. Sensory evaluation showed that texture and color were not affected by irradiation. Taste, the most sensitive sensory attribute showed that hazelnuts retain acceptable sensory quality when irradiated up to a dose of 1.5 kGy.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zadora, A. S., E-mail: as.zadora@physics.msu.ru

The objective of the present study is to consider in more detail the exotic color-charge-glow effect discovered recently and to analyze its possible physical manifestations associated with the treatment of ensembles of color-charged particles at a classical level. The ways in which this effect may appear in arbitrary systems consisting of pointlike massive particles and admitting the partition into elementary configurations like color charges and color dipoles are studied. The possible influence of this effect on particle dynamics (in particular, on gluon distributions) is also examined. Particle collisions at a given impact parameters are considered for a natural regularization ofmore » emerging expressions. It is shown that, in the case of reasonable impact-parameter values, collisions may proceed in the electrodynamic mode, in which case the charge-glow contribution to field strengths is suppressed in relation to what we have in the electrodynamic picture. From an analysis of the color-echo situation, it follows that the above conclusion remains valid for more complicated particle configurations as well, since hard gluon fields may arise only owing to a direct collision rather than owing to any echo-like effects.« less

LANDSAT menhaden and thread herring resources investigation. [Gulf of Mexico

NASA Technical Reports Server (NTRS)

Kemmerer, A. J. (Principal Investigator); Brucks, J. T.; Butler, J. A.; Faller, K. H.; Holley, H. J.; Leming, T. D.; Savastano, K. J.; Vanselous, T. M.

1977-01-01

The author has identified the following significant results. The relationship between the distribution of menhaden and selected oceanographic parameters (water color, turbidity, and possibly chlorophyll concentrations) was established. Similar relationships for thread herring were not established nor were relationships relating to the abundance of either species. Use of aircraft and LANDSAT remote sensing instruments to measure or infer a set of basic oceanographic parameters was evaluated. Parameters which could be accurately inferred included surface water temperature, salinity, and color. Water turbidity (Secchi disk) was evaluated as marginally inferrable from the LANDSAT MSS data and chlorophyll-a concentrations as less than marginal. These evaluations considered the parameters only as experienced in the two test areas using available sensors and statistical techniques.

Colour detection thresholds in faces and colour patches.

PubMed

Tan, Kok Wei; Stephen, Ian D

2013-01-01

Human facial skin colour reflects individuals' underlying health (Stephen et al 2011 Evolution & Human Behavior 32 216-227); and enhanced facial skin CIELab b* (yellowness), a* (redness), and L* (lightness) are perceived as healthy (also Stephen et al 2009a International Journal of Primatology 30 845-857). Here, we examine Malaysian Chinese participants' detection thresholds for CIELab L* (lightness), a* (redness), and b* (yellowness) colour changes in Asian, African, and Caucasian faces and skin coloured patches. Twelve face photos and three skin coloured patches were transformed to produce four pairs of images of each individual face and colour patch with different amounts of red, yellow, or lightness, from very subtle (deltaE = 1.2) to quite large differences (deltaE = 9.6). Participants were asked to decide which of sequentially displayed, paired same-face images or colour patches were lighter, redder, or yellower. Changes in facial redness, followed by changes in yellowness, were more easily discriminated than changes in luminance. However, visual sensitivity was not greater for redness and yellowness in nonface stimuli, suggesting red facial skin colour special salience. Participants were also significantly better at recognizing colour differences in own-race (Asian) and Caucasian faces than in African faces, suggesting the existence of cross-race effect in discriminating facial colours. Humans' colour vision may have been selected for skin colour signalling (Changizi et al 2006 Biology Letters 2 217-221), enabling individuals to perceive subtle changes in skin colour, reflecting health and emotional status.

Pixel-based skin segmentation in psoriasis images.

PubMed

George, Y; Aldeen, M; Garnavi, R

2016-08-01

In this paper, we present a detailed comparison study of skin segmentation methods for psoriasis images. Different techniques are modified and then applied to a set of psoriasis images acquired from the Royal Melbourne Hospital, Melbourne, Australia, with aim of finding the best technique suited for application to psoriasis images. We investigate the effect of different colour transformations on skin detection performance. In this respect, explicit skin thresholding is evaluated with three different decision boundaries (CbCr, HS and rgHSV). Histogram-based Bayesian classifier is applied to extract skin probability maps (SPMs) for different colour channels. This is then followed by using different approaches to find a binary skin map (SM) image from the SPMs. The approaches used include binary decision tree (DT) and Otsu's thresholding. Finally, a set of morphological operations are implemented to refine the resulted SM image. The paper provides detailed analysis and comparison of the performance of the Bayesian classifier in five different colour spaces (YCbCr, HSV, RGB, XYZ and CIELab). The results show that histogram-based Bayesian classifier is more effective than explicit thresholding, when applied to psoriasis images. It is also found that decision boundary CbCr outperforms HS and rgHSV. Another finding is that the SPMs of Cb, Cr, H and B-CIELab colour bands yield the best SMs for psoriasis images. In this study, we used a set of 100 psoriasis images for training and testing the presented methods. True Positive (TP) and True Negative (TN) are used as statistical evaluation measures.

Estimation of kinetic parameters of anthocyanins and color degradation in vitamin C fortified cranberry juice during storage.

PubMed

Roidoung, Sunisa; Dolan, Kirk D; Siddiq, Muhammad

2017-04-01

Color degradation in cranberry juice during storage is the most common consumer complaint. To enhance nutritional quality, juice is typically fortified with vitamin C. This study determined effect of gallic acid, a natural antioxidant, for the preservation of anthocyanins (ACYs) and color, and estimated kinetics of ACYs and color degradation. Juice, fortified with 40-80mg/100mL vitamin C and 0-320mg/100mL gallic acid, was pasteurized at 85°C for 1min and stored at 23°C for 16days. Total monomeric anthocyanins and red color intensity were evaluated spectrophotometrically and data were used to determine degradation rate constants (k values) and order of reaction (n) of ACYs and color. Due to high correlation, k and n could not be estimated simultaneously. To overcome this difficulty, both n and k were held at different constant values in separate analyses to allow accurate estimation of each. Parameters n and k were modeled empirically as functions of vitamin C, and of vitamin C and gallic acid, respectively. Reaction order n ranged from 1.2 to 4.4, and decreased with increasing vitamin C concentration. The final model offers an effective tool that could be used for predicting ACYs and color retention in cranberry juice during storage. Copyright © 2017. Published by Elsevier Ltd.

Spectroscopy of late type giant stars

NASA Astrophysics Data System (ADS)

Spaenhauer, A.; Thevenin, F.

1984-06-01

An attempt to calibrate broadband RGU colors of late type giant stars in terms of the physical parameters of the objects is reported. The parameters comprise the effective temperature, surface gravity and global metal abundance with respect to the sun. A selection of 21 giant star candidates in the Basel fields Plaut 1, Centaurus III and near HD 95540 were examined to obtain a two color plot. Attention is focused on the G-R color range 1.5-2.15 mag, i.e., spectral types K0-K5. A relationship between R and the metallicity is quantified and shown to have a correlation coefficient of 0.93. No correlation is found between metallicity and gravity or R and the effective temperature.

An ecological valence theory of human color preference

PubMed Central

Palmer, Stephen E.; Schloss, Karen B.

2010-01-01

Color preference is an important aspect of visual experience, but little is known about why people in general like some colors more than others. Previous research suggested explanations based on biological adaptations [Hurlbert AC, Ling YL (2007) Curr Biol 17:623–625] and color-emotions [Ou L-C, Luo MR, Woodcock A, Wright A (2004) Color Res Appl 29:381–389]. In this article we articulate an ecological valence theory in which color preferences arise from people’s average affective responses to color-associated objects. An empirical test provides strong support for this theory: People like colors strongly associated with objects they like (e.g., blues with clear skies and clean water) and dislike colors strongly associated with objects they dislike (e.g., browns with feces and rotten food). Relative to alternative theories, the ecological valence theory both fits the data better (even with fewer free parameters) and provides a more plausible, comprehensive causal explanation of color preferences. PMID:20421475

Nimbus 7 Coastal Zone Color Scanner (CZCS). Level 1 data product users' guide

NASA Technical Reports Server (NTRS)

Williams, S. P.; Szajna, E. F.; Hovis, W. A.

1985-01-01

The coastal zone color scanner (CZCS) is a scanning multispectral radiometer designed specifically for the remote sensing of Ocean Color parameters from an Earth orbiting space platform. A technical manual which is intended for users of NIMBUS 7 CZCS Level 1 data products is presented. It contains information needed by investigators and data processing personnel to operate on the data using digital computers and related equipment.

Color quality of pigments in cochineals (Dactylopius coccus Costa). Geographical origin characterization using multivariate statistical analysis.

PubMed

Méndez, Jesús; González, Mónica; Lobo, M Gloria; Carnero, Aurelio

2004-03-10

The commercial value of a cochineal (Dactylopius coccus Costa) sample is associated with its color quality. Because the cochineal is a legal food colorant, its color quality is generally understood as its pigment content. Simply put, the higher this content, the more valuable the sample is to the market. In an effort to devise a way to measure the color quality of a cochineal, the present study evaluates different parameters of color measurement such as chromatic attributes (L*, and a*), percentage of carminic acid, tint determination, and chromatographic profile of pigments. Tint determination did not achieve this objective because this parameter does not correlate with carminic acid content. On the other hand, carminic acid showed a highly significant correlation (r = - 0.922, p = 0.000) with L* values determined from powdered cochineal samples. The combination of the information from the spectrophotometric determination of carminic acid with that of the pigment profile acquired by liquid chromatography (LC) and the composition of the red and yellow pigment groups, also acquired by LC, enables greater accuracy in judging the quality of the final sample. As a result of this study, it was possible to achieve the separation of cochineal samples according to geographical origin using two statistical techniques: cluster analysis and principal component analysis.

How to characterize terrains on 4 Vesta using Dawn Framing Camera color bands?

NASA Astrophysics Data System (ADS)

Le Corre, Lucille; Reddy, Vishnu; Nathues, Andreas; Cloutis, Edward A.

2011-12-01

We present methods for terrain classification on 4 Vesta using Dawn Framing Camera (FC) color information derived from laboratory spectra of HED meteorites and other Vesta-related assemblages. Color and spectral parameters have been derived using publicly available spectra of these analog materials to identify the best criteria for distinguishing various terrains. We list the relevant parameters for identifying eucrites, diogenites, mesosiderites, pallasites, clinopyroxenes and olivine + orthopyroxene mixtures using Dawn FC color cubes. Pseudo Band I minima derived by fitting a low order polynomial to the color data are found to be useful for extracting the pyroxene chemistry. Our investigation suggests a good correlation (R2 = 0.88) between laboratory measured ferrosilite (Fs) pyroxene chemistry vs. those from pseudo Band I minima using equations from Burbine et al. (Burbine, T.H., Buchanan, P.C., Dolkar, T., Binzel, R.P. [2009]. Planetary Science 44, 1331-1341). The pyroxene chemistry information is a complementary terrain classification capability beside the color ratios. We also investigated the effects of exogenous material (i.e., CM2 carbonaceous chondrites) on the spectra of HEDs using laboratory mixtures of these materials. Our results are the basis for an automated software pipeline that will allow us to classify terrains on 4 Vesta efficiently.

Integrated High Resolution Digital Color Light Sensor in 130 nm CMOS Technology.

PubMed

Strle, Drago; Nahtigal, Uroš; Batistell, Graciele; Zhang, Vincent Chi; Ofner, Erwin; Fant, Andrea; Sturm, Johannes

2015-07-22

This article presents a color light detection system integrated in 130 nm CMOS technology. The sensors and corresponding electronics detect light in a CIE XYZ color luminosity space using on-chip integrated sensors without any additional process steps, high-resolution analog-to-digital converter, and dedicated DSP algorithm. The sensor consists of a set of laterally arranged integrated photodiodes that are partly covered by metal, where color separation between the photodiodes is achieved by lateral carrier diffusion together with wavelength-dependent absorption. A high resolution, hybrid, ∑∆ ADC converts each photo diode's current into a 22-bit digital result, canceling the dark current of the photo diodes. The digital results are further processed by the DSP, which calculates normalized XYZ or RGB color and intensity parameters using linear transformations of the three photo diode responses by multiplication of the data with a transformation matrix, where the coefficients are extracted by training in combination with a pseudo-inverse operation and the least-mean square approximation. The sensor system detects the color light parameters with 22-bit accuracy, consumes less than 60 μA on average at 10 readings per second, and occupies approx. 0.8 mm(2) of silicon area (including three photodiodes and the analog part of the ADC). The DSP is currently implemented on FPGA.

Illustrating Chromatography with Colorful Proteins

ERIC Educational Resources Information Center

Lefebvre, Brian G.; Farrell, Stephanie; Dominiak, Richard S.

2007-01-01

Advances in biology are prompting new discoveries in the biotechnology, pharmaceutical, medical technology, and chemical industries. This paper presents a detailed description of an anion exchange chromatography experiment using a pair of colorful proteins and summarizes the effect of operating parameters on protein separation. This experiment…

Design of the scanning mode coated glass color difference online detection system

NASA Astrophysics Data System (ADS)

Bi, Weihong; Zhang, Yu; Wang, Dajiang; Zhang, Baojun; Fu, Guangwei

2008-03-01

A design of scanning mode coated glass color difference online detection system was introduced. The system consisted of color difference data acquirement part and orbit control part. The function of the color difference data acquirement part was to acquire glass spectral reflectance and then processed them to get the color difference value. Using fiber for light guiding, the reflected light from surface of glass was transmitted into light division part, and the dispersive light was imaged on linear CCD, and then the output signals from the CCD was sampled pixel by pixel, and the spectral reflectance of coated glass was obtained finally. Then, the acquired spectral reflectance signals was sent to industrial personal computer through USB interface, using standard color space and color difference formula nominated by International Commission on Illumination (CIE) in 1976 to process these signals, and the reflected color parameter and color difference of coated glass was gained in the end. The function of the orbit control part was to move the detection probe by way of transverse scanning mode above the glass strip, and control the measuring start-stop time of the color difference data acquirement part at the same time. The color difference data acquirement part of the system was put on the orbit which is after annealing area in coated glass production line, and the protected fiber probe was placed on slide of the orbit. Using single chip microcomputer to control transmission mechanism of the slide, which made the slide move by way of transverse scanning mode on the glass strip, meanwhile, the color difference data acquirement part of the system was also controlled by the single chip microcomputer, and it made the acquirement part measure color difference data when the probe reached the needed working speed and required place on the glass strip. The scanning mode coated glass color difference online detection system can measure color parameter and color difference of each transverse point on glass strip, it can also measure lengthways color stability on glass strip. Furthermore, the measuring results can be transmitted to coated control room through intranet, so it is very useful to improve producing technique in time. In addition, equipping necessary marking machine, this system can classify glass board automatically based on the measuring result.

Color normalization for robust evaluation of microscopy images

NASA Astrophysics Data System (ADS)

Švihlík, Jan; Kybic, Jan; Habart, David

2015-09-01

This paper deals with color normalization of microscopy images of Langerhans islets in order to increase robustness of the islet segmentation to illumination changes. The main application is automatic quantitative evaluation of the islet parameters, useful for determining the feasibility of islet transplantation in diabetes. First, background illumination inhomogeneity is compensated and a preliminary foreground/background segmentation is performed. The color normalization itself is done in either lαβ or logarithmic RGB color spaces, by comparison with a reference image. The color-normalized images are segmented using color-based features and pixel-wise logistic regression, trained on manually labeled images. Finally, relevant statistics such as the total islet area are evaluated in order to determine the success likelihood of the transplantation.

Maceration enzymes and mannoproteins: a possible strategy to increase colloidal stability and color extraction in red wines.

PubMed

Guadalupe, Zenaida; Palacios, Antonio; Ayestaran, Belén

2007-06-13

Different strategies were adopted to achieve increases in color stability in Tempranillo wines: (i) addition of maceration enzymes directly to the must, (ii) addition of commercial mannoproteins to the must, and (iii) inoculation of must with yeast overexpressed of mannoproteins. The addition of enzymes favored color extraction, and the wines obtained presented higher values of wine color, color intensity, bisulfite-stable color, and visually enhanced color intensity. The enzyme hydrolytic activity produced an increase in the acid polysaccharide content and polyphenol index and yielded to wines with more astringency, tannin, and length. Added mannoproteins had clearer effects on the analyzed parameters than yeast. Contrary to what may be thought, mannoproteins did not maintain the extracted polyphenols in colloidal dispersion and neither ensured color stability. These compounds clearly modified the gustative structure of the wines, enhancing the sweetness and roundness.

Polarization independent subtractive color printing based on ultrathin hexagonal nanodisk-nanohole hybrid structure arrays.

PubMed

Zhao, Jiancun; Yu, Xiaochang; Yang, Xiaoming; Xiang, Quan; Duan, Huigao; Yu, Yiting

2017-09-18

Structural color printing based on plasmonic metasurfaces has been recognized as a promising alternative to the conventional dye colorants, though the color brightness and polarization tolerance are still a great challenge for practical applications. In this work, we report a novel plasmonic metasurface for subtractive color printing employing the ultrathin hexagonal nanodisk-nanohole hybrid structure arrays. Through both the experimental and numerical investigations, the subtractive color thus generated taking advantages of extraordinary low transmission (ELT) exhibits high brightness, polarization independence and wide color tunability by varying key geometrical parameters. In addition, other regular patterns including square, pentagonal and circular shapes are also surveyed, and reveal a high color brightness, wide gamut and polarization independence as well. These results indicate that the demonstrated plasmonic metasurface has various potential applications in high-definition displays, high-density optical data storage, imaging and filtering technologies.

Slope-aspect color shading for parametric surfaces

NASA Technical Reports Server (NTRS)

Moellering, Harold J. (Inventor); Kimerling, A. Jon (Inventor)

1991-01-01

The invention is a method for generating an image of a parametric surface, such as the compass direction toward which each surface element of terrain faces, commonly called the slope-aspect azimuth of the surface element. The method maximizes color contrast to permit easy discrimination of the magnitude, ranges, intervals or classes of a surface parameter while making it easy for the user to visualize the form of the surface, such as a landscape. The four pole colors of the opponent process color theory are utilized to represent intervals or classes at 90 degree angles. The color perceived as having maximum measured luminance is selected to portray the color having an azimuth of an assumed light source and the color showing minimum measured luminance portrays the diametrically opposite azimuth. The 90 degree intermediate azimuths are portrayed by unique colors of intermediate measured luminance, such as red and green. Colors between these four pole colors are used which are perceived as mixtures or combinations of their bounding colors and are arranged progressively between their bounding colors to have perceived proportional mixtures of the bounding colors which are proportional to the interval's angular distance from its bounding colors.

Prediction of HDR quality by combining perceptually transformed display measurements with machine learning

NASA Astrophysics Data System (ADS)

Choudhury, Anustup; Farrell, Suzanne; Atkins, Robin; Daly, Scott

2017-09-01

We present an approach to predict overall HDR display quality as a function of key HDR display parameters. We first performed subjective experiments on a high quality HDR display that explored five key HDR display parameters: maximum luminance, minimum luminance, color gamut, bit-depth and local contrast. Subjects rated overall quality for different combinations of these display parameters. We explored two models | a physical model solely based on physically measured display characteristics and a perceptual model that transforms physical parameters using human vision system models. For the perceptual model, we use a family of metrics based on a recently published color volume model (ICT-CP), which consists of the PQ luminance non-linearity (ST2084) and LMS-based opponent color, as well as an estimate of the display point spread function. To predict overall visual quality, we apply linear regression and machine learning techniques such as Multilayer Perceptron, RBF and SVM networks. We use RMSE and Pearson/Spearman correlation coefficients to quantify performance. We found that the perceptual model is better at predicting subjective quality than the physical model and that SVM is better at prediction than linear regression. The significance and contribution of each display parameter was investigated. In addition, we found that combined parameters such as contrast do not improve prediction. Traditional perceptual models were also evaluated and we found that models based on the PQ non-linearity performed better.

Skin color parameters and Fitzpatrick phototypes in estimating the risk of skin cancer: A case-control study in the Polish population.

PubMed

Sitek, Aneta; Rosset, Iwona; Żądzińska, Elżbieta; Kasielska-Trojan, Anna; Neskoromna-Jędrzejczak, Aneta; Antoszewski, Bogusław

2016-04-01

Light skin pigmentation is a known risk factor for skin cancer. Skin color parameters and Fitzpatrick phototypes were evaluated in terms of their usefulness in predicting the risk of skin cancer. A case-control study involved 133 individuals with skin cancer (100 with basal cell carcinoma, 21 with squamous cell carcinoma, 12 with melanoma) and 156 healthy individuals. All of them had skin phototype determined and spectrophotometric skin color measurements were done on the inner surfaces of their arms and on the buttock. Using those data, prediction models were built and subjected to 17-fold stratified cross-validation. A model, based on skin phototypes, was characterized by area under the receiver operating characteristic curve = 0.576 and exhibited a lower predictive power than the models, which were mostly based on spectrophotometric variables describing pigmentation levels. The best predictors of skin cancer were R coordinate of RGB color space (area under the receiver operating characteristic curve 0.687) and melanin index (area under the receiver operating characteristic curve 0.683) for skin on the buttock. A small number of patients were studied. Models were not externally validated. Skin color parameters are more accurate predictors of skin cancer occurrence than skin phototypes. Spectrophotometry is a quick, easy, and affordable method offering relatively good predictive power. Copyright © 2015 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

Solution of multi-element LED light sources development automation problem

NASA Astrophysics Data System (ADS)

Chertov, Aleksandr N.; Gorbunova, Elena V.; Korotaev, Valery V.; Peretyagin, Vladimir S.

2014-09-01

The intensive development of LED technologies resulted in the creation of multicomponent light sources in the form of controlled illumination devices based on usage of mentioned LED technologies. These light sources are used in different areas of production (for example, in the food industry for sorting products or in the textile industry for quality control, etc.). The use of LED lighting products in the devices used in specialized lighting, became possible due to wide range of colors of light, LED structures (which determines the direction of radiation, the spatial distribution and intensity of the radiation, electrical, heat, power and other characteristics), and of course, the possibility of obtaining any shade in a wide dynamic range of brightness values. LED-based lighting devices are notable for the diversity of parameters and characteristics, such as color radiation, location and number of emitters, etc. Although LED technologies have several advantages, however, they require more attention if you need to ensure a certain character of illumination distribution and/or distribution of the color picture at a predetermined distance (for example, at flat surface, work zone, area of analysis or observation). This paper presents software designed for the development of the multicomponent LED light sources. The possibility of obtaining the desired color and energy distribution at the zone of analysis by specifying the spatial parameters of the created multicomponent light source and using of real power, spectral and color parameters and characteristics of the LEDs is shown as well.

The extended Kubelka-Munk theory and its application to colloidal systems

NASA Astrophysics Data System (ADS)

Alcaraz de la Osa, R.; Fernández, A.; Gutiérrez, Y.; Ortiz, D.; González, F.; Moreno, F.; Saiz, J. M.

2017-08-01

The use of nanoparticles is spreading in many fields and a frequent way of preparing them is in the form of colloids, whose characterization becomes increasingly important. The spectral reflectance and transmittance curves of such colloids exhibit a strong dependence with the main parameters of the system. By means of a two-flux model we have performed a colorimetric study of gold colloids varying several parameters of the system, including the radius of the particles, the particle number density, the thickness of the system and the refractive index of the surrounding medium. In all cases, trajectories in the L*a*b* color space have been obtained, as well as the evolution of the luminosity, chroma and hue, either for reflectance or transmittance. The observed colors agree well with typical colors found in the literature for colloidal gold, and could allow for a fast assessment of the parameters involved, e.g., the radius of the nanoparticle during the fabrication process.

Adhesive Systems as an Alternative Material for Color Masking of White Spot Lesions: Do They Work?

PubMed

de Lacerda, Ana Júlia Farias; da Silva Ávila, Daniele Mara; Borges, Alessandra Buhler; Pucci, Cesar Rogerio; Rocha Gomes Torres, Carlos

2016-01-01

To evaluate the color masking effect of infiltration treatment of artificial white spot lesions (AWSL) using a dedicated resin in comparison to different adhesive systems. Enamel/dentin specimens were obtained from bovine incisors and baseline color was assessed using a reflectance spectrophotometer, according to the CIE L*a*b* system. AWSL were produced using a buffered acid solution and a new color evaluation was performed. The specimens were divided into 8 groups: control: artificial saliva changed daily for 7 days; IC: infiltrating resin Icon; EC: EquiaCoat; FU: Futurabond U; SBU: Single Bond U; SBMP: Scotchbond MP; OB: OptibondFL; BF: Bioforty. After the treatments, the color was evaluated again and the values for the parameters ΔL (change in lightness), Δa (change in chroma), Δb (change in hue), and ΔE (general color difference) were calculated in relation to baseline. Data were analyzed by one-way ANOVA and Tukey's tests. After treatment, ANOVA showed significant differences for all parameters (p = 0.001). Tukey's test showed the greatest lightness reduction (ΔL) for the IC group, followed by EC, FU, and SBU. The SBMP, OB, and BF groups were similar to the control. For Δb values, all groups showed differences in relation to the control, with no differences between them. In relation to ΔE, all groups showed differences in relation to the control (ΔE = 5.24), with no significant differences between them. ΔE values after application of all resinous materials were lower than the threshold of 3.7, indicating effective color masking. The Icon infiltrant produced a greater lightness reduction of white lesions (ΔL). For general color difference (ΔE), all the resinous materials tested were able to color mask artificial AWSL.

The colors of cometary nuclei and other primitive bodies

NASA Astrophysics Data System (ADS)

Toth, I.; Lamy, P. L.

2005-12-01

Primitive minor objects like Kuiper-belt objects (KBOs), Centaurs, cometary nuclei and low-albedo asteroids contain a considerable amount of information regarding the formation of early solar system planetesimals and some of the primordial processes. Broadband colors by themselves offer limited insight into surface composition but correlations either between different color indices or with other (e.g., orbital) parameters can shed some light on the questions of the composition and the evolution of the minor objects. Furthermore, a systematic comparison of the color indices of various populations may provide clues on their relationships, and concur along with dynamical studies, to establish a scenario of their formation and evolution in the solar system. We present new color results on cometary nuclei obtained with the Hubble Space Telescope (HST) whose superior resolution enables us to accurately isolate the nucleus signals from the surrounding comae. By combining with scrutinized available data obtained with ground-based telescopes, we accumulated a sample of 39 cometary nuclei, 34 ecliptic comets (ECs) and 5 nearly-isotropic comets (NICs) using the nomenclature of Levison (1996). We analyze color distributions and color-color correlations as well as correlations with other physical parameters. We present our own compilation of colors of 282 objects in the outer solar system, separately considering the different dynamical populations, classical KBOs in low and high-inclination orbits, resonant KBOs (practically Plutinos), scattered-disk objects (SDOs) and Centaurs. We perform a systematic analysis of color distributions of all plausible parent-child combinations and conclude by synthesizing the implications of the colors for the origin of ecliptic comets. We acknowledge the support of the French "Programme National de Planétologie", jointly funded by CNRS and CNES, and of the bilateral French--Hungarian cooperation program. I. Toth further acknowledges the support of the Université de Provence, of the Hungarian Academy of Sciences through grant No. 9871.

Effect of ultrasound irradiation on the evolution of color properties and major phenolic compounds in wine during storage.

PubMed

Zhang, Qing-An; Wang, Ting-Ting

2017-11-01

In this paper, the effects of ultrasound irradiation were investigated on the evolution of color properties and major phenolic compounds during wine storage. The results indicate that the changing trends of color parameters are very similar in both the ultrasonically-treated and untreated wines, meanwhile the evolutions of malvidin-3-O-glucoside, monomeric flavan-3-ols and phenolic acids also demonstrate some similar patterns in all wines during storage, respectively. In summary, the ultrasound irradiation does not only temporally influence the color characteristics and phenolic compounds of wine, but also have a longer effect on their evolutions during wine storage. Furthermore, the ultrasonically-treated wine had a quicker changing trend than that of the untreated wine regarding the studied parameters. All these results indicate that the ultrasound might be as a feasible and promising novel technology for wineries to produce more red wines with the similar quality as the traditionally-aged wine in a shorter time. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of high hydrostatic pressure on the color and texture parameters of refrigerated Caiman (Caiman crocodilus yacare) tail meat.

PubMed

Canto, A C V C S; Lima, B R C C; Cruz, A G; Lázaro, C A; Freitas, D G C; Faria, Jose A F; Torrezan, R; Freitas, M Q; Silva, T P J

2012-07-01

The effect of applying high hydrostatic pressure (HHP) on the instrumental parameters of color and texture and sensory characteristics of alligator meat were evaluated. Samples of alligator tail meat were sliced, vacuum-packed, pressurized and distributed into four groups: control, treated with 200 MPa/10 min, 300 MPa/10 min and 400 MPa/10 min, then stored at 4°C±1°C for 45 days. Instrumental color, texture profile and a sensory profiling using quantitative descriptive analysis were carried out on the 1st, 15th, 30th and 45th days of storage. HHP was shown to affect the color and texture of the product, and the sensory descriptors (p<0.05). The results suggest that high pressure is a promising technology for the processing of alligator meat, especially low pressures (200 MPa) which can have positive effects on the quality of the product. Copyright © 2012 Elsevier Ltd. All rights reserved.

Sseven-color Photometry and Classification of Stars in the Vicinity of the Emission Nebula Sh2-205

NASA Astrophysics Data System (ADS)

Čepas, V.; Zdanavičius, J.; Zdanavičius, K.; Straižys, V.; Laugalys, V.

We present the results of CCD photometry in the seven-color Vilnius system for 922 stars down to V = 17 mag in a 1.5 square degree field at the northern edge of the H II region Sh2-205, at the Perseus and Camelopardalis border. Using the intrinsic color indices and photometric reddening-free Q-parameters, two-dimensional spectral types for most stars are determined.

Beef quality parameters estimation using ultrasound and color images

PubMed Central

2015-01-01

Background Beef quality measurement is a complex task with high economic impact. There is high interest in obtaining an automatic quality parameters estimation in live cattle or post mortem. In this paper we set out to obtain beef quality estimates from the analysis of ultrasound (in vivo) and color images (post mortem), with the measurement of various parameters related to tenderness and amount of meat: rib eye area, percentage of intramuscular fat and backfat thickness or subcutaneous fat. Proposal An algorithm based on curve evolution is implemented to calculate the rib eye area. The backfat thickness is estimated from the profile of distances between two curves that limit the steak and the rib eye, previously detected. A model base in Support Vector Regression (SVR) is trained to estimate the intramuscular fat percentage. A series of features extracted on a region of interest, previously detected in both ultrasound and color images, were proposed. In all cases, a complete evaluation was performed with different databases including: color and ultrasound images acquired by a beef industry expert, intramuscular fat estimation obtained by an expert using a commercial software, and chemical analysis. Conclusions The proposed algorithms show good results to calculate the rib eye area and the backfat thickness measure and profile. They are also promising in predicting the percentage of intramuscular fat. PMID:25734452

Degradation kinetics of peroxidase enzyme, phenolic content, and physical and sensorial characteristics in broccoli (Brassica oleracea L. ssp. Italica) during blanching.

PubMed

Gonçalves, Elsa M; Pinheiro, Joaquina; Alegria, Carla; Abreu, Marta; Brandão, Teresa R S; Silva, Cristina L M

2009-06-24

The effects of water blanching treatment on peroxidase inactivation, total phenolic content, color parameters [-a*/b* and hue (h degrees*)], texture (maximum shear force), and sensory attributes (color and texture, evaluated by a trained panel) of broccoli (Brassica oleracea L. ssp. Italica) were studied at five temperatures (70, 75, 80, 85, and 90 degrees C). Experimental results showed that all studied broccoli quality parameters suffered significative changes due to blanching treatments. The vegetal total phenolic content showed a marked decline. Degradation on objective color and texture measurements and alterations in sensorial attributes were detected. Correlations between sensory and instrumental measurements have been found. Under the conditions 70 degrees C and 6.5 min or 90 degrees C and 0.4 min, 90% of the initial peroxidase activity was reduced. At these conditions, no significant alterations were detected by panelists, and a small amount of phenolic content was lost (ca. 16 and 10%, respectively). The peroxidase inactivation and phenolic content degradation were found to follow first-order reaction models. The zero-order reaction model showed a good fit to the broccoli color (-a*/b* and h degrees*), texture, and sensory parameters changes. The temperature effect was well-described by the Arrhenius law.

Color Correction Parameter Estimation on the Smartphone and Its Application to Automatic Tongue Diagnosis.

PubMed

Hu, Min-Chun; Cheng, Ming-Hsun; Lan, Kun-Chan

2016-01-01

An automatic tongue diagnosis framework is proposed to analyze tongue images taken by smartphones. Different from conventional tongue diagnosis systems, our input tongue images are usually in low resolution and taken under unknown lighting conditions. Consequently, existing tongue diagnosis methods cannot be directly applied to give accurate results. We use the SVM (support vector machine) to predict the lighting condition and the corresponding color correction matrix according to the color difference of images taken with and without flash. We also modify the state-of-the-art work of fur and fissure detection for tongue images by taking hue information into consideration and adding a denoising step. Our method is able to correct the color of tongue images under different lighting conditions (e.g. fluorescent, incandescent, and halogen illuminant) and provide a better accuracy in tongue features detection with less processing complexity than the prior work. In this work, we proposed an automatic tongue diagnosis framework which can be applied to smartphones. Unlike the prior work which can only work in a controlled environment, our system can adapt to different lighting conditions by employing a novel color correction parameter estimation scheme.

Star-forming Galaxies as AGN Imposters? A Theoretical Investigation of the Mid-infrared Colors of AGNs and Extreme Starbursts

NASA Astrophysics Data System (ADS)

Satyapal, Shobita; Abel, Nicholas P.; Secrest, Nathan J.

2018-05-01

We conduct for the first time a theoretical investigation of the mid-infrared spectral energy distribution (SED) produced by dust heated by an active galactic nucleus (AGN) and an extreme starburst. These models employ an integrated modeling approach using photoionization and stellar population synthesis models in which both the line and emergent continuum is predicted from gas exposed to the ionizing radiation from a young starburst and an AGN. In this work, we focus on the infrared colors from the Wide-field Infrared Survey Explorer, predicting the dependence of the colors on the input radiation field, the interstellar medium conditions, the obscuring column, and the metallicity. We find that an extreme starburst can mimic an AGN in two band mid-infrared color cuts employed in the literature. However, the three-band color cuts employed in the literature require starbursts with extremely high ionization parameters or gas densities. We show that the extreme mid-infrared colors seen in some blue compact dwarf galaxies are not due to metallicity but rather a combination of high ionization parameters and high column densities. Based on our theoretical calculations, we present a theoretical mid-infrared color cut that will exclude even the most extreme starburst that we have modeled in this work. The theoretical AGN demarcation region presented here can be used to identify elusive AGN candidates for future follow-up studies with the James Webb Space Telescope. The full suite of simulated SEDs are available online.

The application of color display techniques for the analysis of Nimbus infrared radiation data

NASA Technical Reports Server (NTRS)

Allison, L. J.; Cherrix, G. T.; Ausfresser, H.

1972-01-01

A color enhancement system designed for the Applications Technology Satellite (ATS) spin scan experiment has been adapted for the analysis of Nimbus infrared radiation measurements. For a given scene recorded on magnetic tape by the Nimbus scanning radiometers, a virtually unlimited number of color images can be produced at the ATS Operations Control Center from a color selector paper tape input. Linear image interpolation has produced radiation analyses in which each brightness-color interval has a smooth boundary without any mosaic effects. An annotated latitude-longitude gridding program makes it possible to precisely locate geophysical parameters, which permits accurate interpretation of pertinent meteorological, geological, hydrological, and oceanographic features.

Development and usage of a false color display technique for presenting Seasat-A scatterometer data

NASA Technical Reports Server (NTRS)

Jackson, C. B.

1980-01-01

A computer generated false color program which creates digital multicolor graphics to display geophysical surface parameters measured by the Seasat-A satellite scatterometer (SASS) is described. The data is incrementally scaled over the range of acceptable values and each increment and its data points are assigned a color. The advantage of the false color display is that it visually infers cool or weak data versus hot or intense data by using the rainbow of colors. For example, with wind speeds, levels of yellow and red could be used to imply high winds while green and blue could imply calmer air. The SASS data is sorted into geographic regions and the final false color images are projected onto various world maps with superimposed land/water boundaries.

Alcohol-containing mouthwasheses: effect on composite color.

PubMed

Settembrini, L; Penugonda, B; Scherer, W; Strassler, H; Hittelman, E

1995-01-01

This study investigated whether commercially available mouthwashes could affect or change the color of a hybrid composite resin. Twenty-four disks were fabricated and divided into eight equal groups for testing. At baseline, six colorimetric recordings and color parameters (L*, a*, b*) were recorded for each grouping of disks using a Chroma Meter CR-300 in reflectance mode. The groups of disks were immersed in their respective mouthwashes for 2 minutes a day in a vibratory fashion over a 6-month period. At the end of 6 months, color differences, delta E, were calculated between the base line and test recordings. The results indicate that rinsing with mouthwashes for 6 months can cause a hybrid resin to undergo color variations. Except for one product the color variations were not clinically significant.

Optimal design and evaluation of a color separation grating using rigorous coupled wave analysis

NASA Astrophysics Data System (ADS)

Nagayoshi, Mayumi; Oka, Keiko; Klaus, Werner; Komai, Yuki; Kodate, Kashiko

2006-02-01

In recent years, the technology which separates white light into the three primary colors of Red (R), Green (G) and Blue (B) and adjusts each optical intensity and composites R, G and B to display various colors is required in the development and spread of color visual equipments. Various color separation devices have been proposed and have been put to practical use in color visual equipments. We have focused on a small and light grating-type device which has the possibility of reduction in cost and large-scale production and generates only the three primary colors of R, G and B so that a high saturation level can be obtained. To perform a rigorous analysis and design of color separation gratings, our group has developed a program that is based on the Rigorous Coupled Wave Analysis (RCWA). We then calculated the parameters to obtain a diffraction efficiency of higher than 70% and the color gamut of about 70%. We will report on the design, fabrication and evaluation of color separation gratings that have been optimized for fabrication by laser drawing.

Cathodoluminescent characteristics and light technical parameters of thin-film screens based on oxides and oxysulfides of rare-earth elements

NASA Astrophysics Data System (ADS)

Bondar, Vyacheslav D.; Grytsiv, Myroslav; Groodzinsky, Arkady; Vasyliv, Mykhailo

1995-11-01

Results on creation of thin-film single-crystal high-resolution screens with energy control of luminescence color are presented. In order to create phosphor films ion-plasma technology for deposition of yttrium and lanthanum oxides and oxysulfides activated by rare earth elements has been developed. The screen consists of phosphor film on phosphor substrate with different colors of luminescence (e.g. Y2O3-Eu film with red color on Y3Al5O12- Tb, Ce substrate with green color of luminescence). Electron irradiation causes luminescence with color that depends on energy of the electron beam. The physical reason for color change is that electron beam energy defines electron penetration depth. If the energy is weak, only the film is excited. More powerful beam penetrates into the substrate and thus changes the color of luminescence.

Radiochromic film dosimetry for UV-C treatments of apple fruit

USDA-ARS?s Scientific Manuscript database

Radiochromic films were evaluated for their suitability to estimate UV-C doses and dose uniformity on apple fruit surface. Parameters investigated included film type, color changes of the films in response to different UV-C doses, color stability of films, UV-C light intensity, and temperature. In...

The use of a MODIS band-ratio algorithm versus a new hybrid approach for estimating colored dissolved organic matter (CDOM)

EPA Science Inventory

Satellite remote sensing offers synoptic and frequent monitoring of optical water quality parameters, such as chlorophyll-a, turbidity, and colored dissolved organic matter (CDOM). While traditional satellite algorithms were developed for the open ocean, these algorithms often do...

Ocean color, a three component system?

NASA Technical Reports Server (NTRS)

Yentsch, C. S.; Owen, W. P.

1972-01-01

This study measures the concentrations of phytoplankton chlorophyll and yellow substance in the coastal waters of the Gulf of Maine. Sea surface observations attempt to delineate the principal biochemical parameters responsible for sea surface color. It is shown that the reddish-brown water changed to a blue-green in the open gulf.

Integrated High Resolution Digital Color Light Sensor in 130 nm CMOS Technology

PubMed Central

Strle, Drago; Nahtigal, Uroš; Batistell, Graciele; Zhang, Vincent Chi; Ofner, Erwin; Fant, Andrea; Sturm, Johannes

2015-01-01

This article presents a color light detection system integrated in 130 nm CMOS technology. The sensors and corresponding electronics detect light in a CIE XYZ color luminosity space using on-chip integrated sensors without any additional process steps, high-resolution analog-to-digital converter, and dedicated DSP algorithm. The sensor consists of a set of laterally arranged integrated photodiodes that are partly covered by metal, where color separation between the photodiodes is achieved by lateral carrier diffusion together with wavelength-dependent absorption. A high resolution, hybrid, ∑∆ ADC converts each photo diode’s current into a 22-bit digital result, canceling the dark current of the photo diodes. The digital results are further processed by the DSP, which calculates normalized XYZ or RGB color and intensity parameters using linear transformations of the three photo diode responses by multiplication of the data with a transformation matrix, where the coefficients are extracted by training in combination with a pseudo-inverse operation and the least-mean square approximation. The sensor system detects the color light parameters with 22-bit accuracy, consumes less than 60 μA on average at 10 readings per second, and occupies approx. 0.8 mm2 of silicon area (including three photodiodes and the analog part of the ADC). The DSP is currently implemented on FPGA. PMID:26205275

Translucency of Zirconia Ceramics before and after Artificial Aging.

PubMed

Walczak, Katarzyna; Meißner, Heike; Range, Ursula; Sakkas, Andreas; Boening, Klaus; Wieckiewicz, Mieszko; Konstantinidis, Ioannis

2018-03-11

The aging of zirconia ceramics (Y-TZP) is associated with tetragonal to monoclinic phase transformation. This change in microstructure may affect the optical properties of the ceramic. This study examines the effect of aging on the translucency of different zirconia materials. 120 disc-shaped specimens were fabricated from four zirconia materials: Cercon ht white, BruxZir Solid Zirconia, Zenostar T0, Lava Plus (n = 30 per group). Accelerated aging was performed in a steam autoclave (134°C, 0.2 MPa, 5 hours). CIELab coordinates (L*, a*, b*) and luminous reflectance (Y) were measured with a spectrophotometer before and after aging. Contrast ratio (CR) and translucency parameter (TP) were calculated from the L*, a*, b*, and Y tristimulus values. The general linear model (Bonferroni adjusted) was used to compare both parameters before and after aging, as well as between the different zirconia materials (p ≤ 0.05). CR and TP differed significantly before and after aging in all groups tested. Before aging, Zenostar T showed the highest and Lava Plus showed the lowest translucency. After aging, Cercon ht and Zenostar T showed the highest and BruxZir and Lava Plus the lowest translucency. Aging reduced the translucency in all specimens tested. Furthermore, translucency differed between the zirconia brands tested. Nevertheless, the differences were below the detectability threshold of the human eye. The aging process can influence the translucency and thus the esthetic outcome of zirconia restorations; however, the changes in translucency were minimal and probably undetectable by the human eye. © 2018 by the American College of Prosthodontists.

Daytime Changes of Skin Biophysical Characteristics: A Study of Hydration, Transepidermal Water Loss, pH, Sebum, Elasticity, Erythema, and Color Index on Middle Eastern Skin.

PubMed

Firooz, Alireza; Zartab, Hamed; Sadr, Bardia; Bagherpour, Leili Naraghi; Masoudi, Aidin; Fanian, Ferial; Dowlati, Yahya; Ehsani, Amir Hooshang; Samadi, Aniseh

2016-01-01

The exposure of skin to ultraviolet radiation and temperature differs significantly during the day. It is reasonable that biophysical parameters of human skin have periodic daily fluctuation. The objective of this study was to study the fluctuations of various biophysical characteristics of Middle Eastern skin in standardized experimental conditions. Seven biophysical parameters of skin including stratum corneum hydration, transepidermal water loss, pH, sebum, elasticity, skin color, and erythema index were measured at three time points (8 a.m., 12 p.m. and 4 p.m.) on the forearm of 12 healthy participants (mean age of 28.4 years) without any ongoing skin disease using the CK MPA 580 device in standard temperature and humidity conditions. A significant difference was observed between means of skin color index at 8 a.m. (175.42 ± 13.92) and 4 p.m. (164.44 ± 13.72, P = 0.025), between the pH at 8 a.m. (5.72 ± 0.48) and 4 p.m. (5.33 ± 0.55, P = 0.001) and pH at 12 p.m. (5.60 ± 0.48) and 4 p.m. (5.33 ± 0.55, P = 0.001). Other comparisons between the means of these parameters at different time points resulted in nonsignificant P values. There are daytime changes in skin color index and pH. Skin color index might be higher and cutaneous pH more basic in the early morning compared to later of the day.

Effects of the Deslagging Process on some Physicochemical Parameters of Honey

PubMed Central

Ranjbar, Ali Mohammad; Sadeghpour, Omid; Khanavi, Mahnaz; Shams Ardekani, Mohammad Reza; Moloudian, Hamid; Hajimahmoodi, Mannan

2015-01-01

Some physicochemical parameters of honey have been introduced by the International Honey Commission to evaluate its quality and origin but processes such as heating and filtering can affect these parameters. In traditional Iranian medicine, deslagging process involves boiling honey in an equal volume of water and removing the slag formed during process. The aim of this study was to determine the effects of deslagging process on parameters of color intensity, diastase evaluation, electrical conductivity, pH, free acidity, refractive index, hydroxy methyl furfural (HMF), proline and water contents according to the International Honey Committee (IHC) standards. The results showed that deslagged honey was significantly different from control honey in terms of color intensity, pH, diastase number, HMF and proline content. It can be concluded that the new standards are needed to regulate deslagged honey. PMID:25901175

Grouping of Bulgarian wines according to grape variety by using statistical methods

NASA Astrophysics Data System (ADS)

Milev, M.; Nikolova, Kr.; Ivanova, Ir.; Minkova, St.; Evtimov, T.; Krustev, St.

2017-12-01

68 different types of Bulgarian wines were studied in accordance with 9 optical parameters as follows: color parameters in XYZ and SIE Lab color systems, lightness, Hue angle, chroma, fluorescence intensity and emission wavelength. The main objective of this research is using hierarchical cluster analysis to evaluate the similarity and the distance between examined different types of Bulgarian wines and their grouping based on physical parameters. We have found that wines are grouped in clusters on the base of the degree of identity between them. There are two main clusters each one with two subclusters. The first one contains white wines and Sira, the second contains red wines and rose. The results from cluster analysis are presented graphically by a dendrogram. The other statistical technique used is factor analysis performed by the Method of Principal Components (PCA). The aim is to reduce the large number of variables to a few factors by grouping the correlated variables into one factor and subdividing the noncorrelated variables into different factors. Moreover the factor analysis provided the possibility to determine the parameters with the greatest influence over the distribution of samples in different clusters. In our study after the rotation of the factors with Varimax method the parameters were combined into two factors, which explain about 80 % of the total variation. The first one explains the 61.49% and correlates with color characteristics, the second one explains 18.34% from the variation and correlates with the parameters connected with fluorescence spectroscopy.

The practical application of reflectance spectrophotometry for the demonstration of haemoglobin and its degradation in bruises

PubMed Central

Hughes, V K; Ellis, P S; Burt, T; Langlois, N E I

2004-01-01

Aims: To develop a non-invasive method to demonstrate the presence of haemoglobin and its degradation products in bruises in live human subjects for the purposes of objectively assisting in the determination of the age of a bruise. Methods: The cuvette holder unit of a Cary 100 Bio UV-Visible Spectrophotometer was replaced with the manufacture’s fibre optic cable and optical reflectance probe. The probe was placed on the skin surface. The absorption spectrum from 780 to 380 nm was collected and transformed into the first derivative. Calculation of the first derivative permits absorption attributed to haemoglobin degradation (primarily to bilirubin, but also haemosiderin) to be separated from absorption by haemoglobin. First derivative and colorimetry values, expressed as CIEL*a*b data, were derived from scans of 50 bruises. Results: The fibre optic cable and probe allowed the spectrophotometer to collect reproducible absorption spectra of bruises in the skin of living subjects. A bruise at three days has greater negative first derivative values at 480 and 490 nm than does a fresh bruise, indicating the local degradation of haemoglobin. Correlation between the first derivative and the CIEL*a*b “b” values in a series of bruises indicates that the yellow colour in a bruise is proportional to the amount of local haemoglobin breakdown. Conclusion: The ability to demonstrate the presence of haemoglobin and measure its degradation in bruises in living human subjects by a non-invasive method has not been described previously, and may be of use in the objective ageing of bruises for forensic purposes. PMID:15047735

Pigmentary and photonic coloration mechanisms reveal taxonomic relationships of the Cattlehearts (Lepidoptera: Papilionidae: Parides)

PubMed Central

2014-01-01

Background The colorful wing patterns of butterflies, a prime example of biodiversity, can change dramatically within closely related species. Wing pattern diversity is specifically present among papilionid butterflies. Whether a correlation between color and the evolution of these butterflies exists so far remained unsolved. Results We here investigate the Cattlehearts, Parides, a small Neotropical genus of papilionid butterflies with 36 members, the wings of which are marked by distinctly colored patches. By applying various physical techniques, we investigate the coloration toolkit of the wing scales. The wing scales contain two different, wavelength-selective absorbing pigments, causing pigmentary colorations. Scale ridges with multilayered lamellae, lumen multilayers or gyroid photonic crystals in the scale lumen create structural colors that are variously combined with these pigmentary colors. Conclusions The pigmentary and structural traits strongly correlate with the taxonomical distribution of Parides species. The experimental findings add crucial insight into the evolution of butterfly wing scales and show the importance of morphological parameter mapping for butterfly phylogenetics. PMID:25064167

The study of protein biomarkers to understand the biochemical processes underlying beef color development in young bulls.

PubMed

Gagaoua, Mohammed; Terlouw, E M Claudia; Picard, Brigitte

2017-12-01

This study investigates relationships between 21 biomarkers and meat color traits of Longissimus thoracis muscles of young Aberdeen Angus and Limousin bulls. The relationships found allowed to propose metabolic processes underlying meat color. The color coordinates were related with several biomarkers. The relationships were in some cases breed-dependent and the variability explained in the regression models varied between 31 and 56%. The correlations between biomarkers and color parameters were sometimes opposite between breeds. The PCA using the 21 biomarkers and the instrumental color coordinates showed that these variables discriminated efficiently between the two studied breeds. Results are coherent with earlier studies on other beef breeds showing that several proteins belonging to different but partly related biological pathways involved in muscle contraction, metabolism, heat stress and apoptosis are related to beef color. The results suggest that in future, biomarkers may be used to classify meat cuts sampled early post-mortem according to their forthcoming color. Copyright © 2017 Elsevier Ltd. All rights reserved.

Study on color identification for monitoring and controlling fermentation process of branched chain amino acid

NASA Astrophysics Data System (ADS)

Ma, Lei; Wang, Yizhong; Chen, Ning; Liu, Tiegen; Xu, Qingyang; Kong, Fanzhi

2008-12-01

In this paper, a new method for monitoring and controlling fermentation process of branched chain amino acid (BCAA) was proposed based on color identification. The color image of fermentation broth of BCAA was firstly taken by a CCD camera. Then, it was changed from RGB color model to HIS color model. Its histograms of hue H and saturation S were calculated, which were used as the input of a designed BP network. The output of the BP network was the description of the color of fermentation broth of BCAA. After training, the color of fermentation broth was identified by the BP network according to the histograms of H and S of a fermentation broth image. Along with other parameters, the fermentation process of BCAA was monitored and controlled to start the stationary phase of fermentation soon. Experiments were conducted with satisfied results to show the feasibility and usefulness of color identification of fermentation broth in fermentation process control of BCAA.

Probabilistic distribution and stochastic P-bifurcation of a hybrid energy harvester under colored noise

NASA Astrophysics Data System (ADS)

Mokem Fokou, I. S.; Nono Dueyou Buckjohn, C.; Siewe Siewe, M.; Tchawoua, C.

2018-03-01

In this manuscript, a hybrid energy harvesting system combining piezoelectric and electromagnetic transduction and subjected to colored noise is investigated. By using the stochastic averaging method, the stationary probability density functions of amplitudes are obtained and reveal interesting dynamics related to the long term behavior of the device. From stationary probability densities, we discuss the stochastic bifurcation through the qualitative change which shows that noise intensity, correlation time and other system parameters can be treated as bifurcation parameters. Numerical simulations are made for a comparison with analytical findings. The Mean first passage time (MFPT) is numerical provided in the purpose to investigate the system stability. By computing the Mean residence time (TMR), we explore the stochastic resonance phenomenon; we show how it is related to the correlation time of colored noise and high output power.

Subsurface water parameters: optimization approach to their determination from remotely sensed water color data.

PubMed

Jain, S C; Miller, J R

1976-04-01

A method, using an optimization scheme, has been developed for the interpretation of spectral albedo (or spectral reflectance) curves obtained from remotely sensed water color data. This method used a two-flow model of the radiation flow and solves for the albedo. Optimization fitting of predicted to observed reflectance data is performed by a quadratic interpolation method for the variables chlorophyll concentration and scattering coefficient. The technique is applied to airborne water color data obtained from Kawartha Lakes, Sargasso Sea, and Nova Scotia coast. The modeled spectral albedo curves are compared to those obtained experimentally, and the computed optimum water parameters are compared to ground truth values. It is shown that the backscattered spectral signal contains information that can be interpreted to give quantitative estimates of the chlorophyll concentration and turbidity in the waters studied.

Astrophysical parameters of open star clusters using 2MASS JHKs data

NASA Astrophysics Data System (ADS)

Durgapal, Alok; Bisht, Devendra; Yadav, Ramakant Singh

2018-04-01

In the present analysis we have estimated the fundamental parameters of two poorly studied open star clusters, namely Teutsch 61 and Czernik 3, using 2MASS JHKs data. We have used the color-magnitude and colour-colour diagrams to determine their fundamental parameters.

Shade changing effectiveness of plasdone and blue covarine-based whitening toothpaste on teeth stained with chlorhexidine and black tea.

PubMed

Bergesch, Vania; Baggio Aguiar, Flávio Henrique; Turssi, Cecilia Pedroso; Gomes França, Fabiana Mantovani; Basting, Roberta Tarkany; Botelho Amaral, Flávia Lucisano

2017-01-01

This study evaluated the effectiveness of toothbrushing with whitening toothpaste in altering the shade of stained human enamel. Thirty fragments of human enamel, stained with chlorhexidine/black tea underwent 1000 and 5000 brushing cycles (BC) with ( n = 10): PLS (Gel Dental Day, Bitufo), Close Up White Now, Unilever (COVB) and regular (Gel Dental Night, Bitufo) toothpaste. Images were taken before staining (baseline), after staining (STN) and following 1000 and 5000 BC and were analyzed using the CIELAB parameters (ΔE, Δb and ΔL). Data were submitted to two-way ANOVA (α = 0.05). ΔE was higher from STN to baseline; 1000 BC to STN and 5000 BC to STN ( P < 0.001). Significant differences in Δb values were found from 1000 BC to STN and 5000 BC to STN. For COVB, greater ΔL was observed from 1000 BC to STN, what differed statistically from the regular toothpaste ( P < 0.05). There was no difference between toothpaste when ΔL was calculated from 5000 CB to STN. Toothpaste containing COVB or PLS in association with 5000 BCs showed similar effectiveness in changing enamel shade; but after the first 1000 toothbrushing cycles, the use of COVB toothpaste promoted higher lightness in stained enamel.

LHC constraints on color octet scalars

NASA Astrophysics Data System (ADS)

Hayreter, Alper; Valencia, German

2017-08-01

We extract constraints on the parameter space of the Manohar and Wise model by comparing the cross sections for dijet, top-pair, dijet-pair, t t ¯t t ¯ and b b ¯b b ¯ productions at the LHC with the strongest available experimental limits from ATLAS or CMS at 8 or 13 TeV. Overall we find mass limits around 1 TeV in the most sensitive regions of parameter space, and lower elsewhere. This is at odds with generic limits for color octet scalars often quoted in the literature where much larger production cross sections are assumed. The constraints that can be placed on coupling constants are typically weaker than those from existing theoretical considerations, with the exception of the parameter ηD.

Quality Parameters of Six Cultivars of Blueberry Using Computer Vision

PubMed Central

Celis Cofré, Daniela; Silva, Patricia; Enrione, Javier; Osorio, Fernando

2013-01-01

Background. Blueberries are considered an important source of health benefits. This work studied six blueberry cultivars: “Duke,” “Brigitta”, “Elliott”, “Centurion”, “Star,” and “Jewel”, measuring quality parameters such as °Brix, pH, moisture content using standard techniques and shape, color, and fungal presence obtained by computer vision. The storage conditions were time (0–21 days), temperature (4 and 15°C), and relative humidity (75 and 90%). Results. Significant differences (P < 0.05) were detected between fresh cultivars in pH, °Brix, shape, and color. However, the main parameters which changed depending on storage conditions, increasing at higher temperature, were color (from blue to red) and fungal presence (from 0 to 15%), both detected using computer vision, which is important to determine a shelf life of 14 days for all cultivars. Similar behavior during storage was obtained for all cultivars. Conclusion. Computer vision proved to be a reliable and simple method to objectively determine blueberry decay during storage that can be used as an alternative approach to currently used subjective measurements. PMID:26904598

Color changes kinetics during deep fat frying of carrot slice

NASA Astrophysics Data System (ADS)

Salehi, Fakhreddin

2018-05-01

Heat and mass transfer phenomena take place during frying cause physicochemical changes, which affect the colour and surface of the fried products. The effect of frying temperature on the colour changes and heat transfer during deep fat frying of carrot has been investigated. The colour scale parameters redness (a*), yellowness (b*) and lightness (L*), and color change intensity (ΔE) were used to estimate colour changes during frying as a function of oil temperature. L* value of fried carrot decreased during frying. The redness of fried carrot decreased during the early stages of frying, while it increased afterwards (become more red). A first-order kinetic equation was used for each one of the three colour parameters, in which the rate constant is a function of oil temperatures. The results showed that oil temperature has a significant effect on the colour parameters. Different kinetic models were used to fit the experimental data and the results revealed that the quadratic model was the most suitable to describe the color change intensity (ΔE) (R > 0.96). Center temperature of carrot slice increased with increase in oil temperature and time during frying.

State-of-the-art for large area high resolution gray scale and full color AC plasma flat panel displays

NASA Technical Reports Server (NTRS)

Stoller, Ray A.; Wedding, Donald K.; Friedman, Peter S.

1993-01-01

A development status evaluation is presented for gas plasma display technology, noting how tradeoffs among the parameters of size, resolution, speed, portability, color, and image quality can yield cost-effective solutions for medical imaging, CAD, teleconferencing, multimedia, and both civil and military applications. Attention is given to plasma-based large-area displays' suitability for radar, sonar, and IR, due to their lack of EM susceptibility. Both monochrome and color displays are available.

Interactive color display for multispectral imagery using correlation clustering

NASA Technical Reports Server (NTRS)

Haskell, R. E. (Inventor)

1979-01-01

A method for processing multispectral data is provided, which permits an operator to make parameter level changes during the processing of the data. The system is directed to production of a color classification map on a video display in which a given color represents a localized region in multispectral feature space. Interactive controls permit an operator to alter the size and change the location of these regions, permitting the classification of such region to be changed from a broad to a narrow classification.

The research of statistical properties of colorimetric features of screens with a three-component color formation principle

NASA Astrophysics Data System (ADS)

Zharinov, I. O.; Zharinov, O. O.

2017-12-01

The problem of the research is concerned with quantitative analysis of influence of technological variation of the screen color profile parameters on chromaticity coordinates of the displayed image. Some mathematical expressions which approximate the two-dimensional distribution of chromaticity coordinates of an image, which is displayed on the screen with a three-component color formation principle were proposed. Proposed mathematical expressions show the way to development of correction techniques to improve reproducibility of the colorimetric features of displays.

Nimbus 7 Coastal Zone Color Scanner (CZCS). Level 2 data product users' guide

NASA Technical Reports Server (NTRS)

Williams, S. P.; Szajna, E. F.; Hovis, W. A.

1985-01-01

The coastal zone color scanner (CZCS) is a scanning multispectral radiometer designed for the remote sensing of ocean color parameters from an earth orbiting space platform. A Technical Manual was designed for users of NIMBUS 7 CZCS Level 2 data products. It contains information which describes how the Level 1 data was process to obtain the Level 2 (derived) product. It contains information needed to operate on the data using digital computers and related equipment.

Color quench correction for low level Cherenkov counting.

PubMed

Tsroya, S; Pelled, O; German, U; Marco, R; Katorza, E; Alfassi, Z B

2009-05-01

The Cherenkov counting efficiency varies strongly with color quenching, thus correction curves must be used to obtain correct results. The external (152)Eu source of a Quantulus 1220 liquid scintillation counting (LSC) system was used to obtain a quench indicative parameter based on spectra area ratio. A color quench correction curve for aqueous samples containing (90)Sr/(90)Y was prepared. The main advantage of this method over the common spectra indicators is its usefulness also for low level Cherenkov counting.

Basic calibrations of the photographic RGU system. III - Intermediate and extreme Population II dwarf stars

NASA Astrophysics Data System (ADS)

Buser, R.; Fenkart, R. P.

1990-11-01

This paper presents an extended calibration of the color-magnitude and two-color diagrams and the metal-abundance parameter for the intermediate Population II and the extreme halo dwarfs observed in the Basel Palomar-Schmidt RGU three-color photometric surveys of the galaxy. The calibration covers the metallicity range between values +0.50 and -3.00. It is shown that the calibrations presented are sufficiently accurate to be useful for the future analyses of photographic survey data.

Development of on package indicator sensor for real-time monitoring of meat quality

PubMed Central

Shukla, Vivek; Kandeepan, G.; Vishnuraj, M. R.

2015-01-01

Aim: The aim was to develop an indicator sensor for real-time monitoring of meat quality and to compare the response of indicator sensor with meat quality parameters at ambient temperature. Materials and Methods: Indicator sensor was prepared using bromophenol blue (1% w/v) as indicator solution and filter paper as indicator carrier. Indicator sensor was fabricated by coating indicator solution onto carrier by centrifugation. To observe the response of indicator sensor buffalo meat was packed in polystyrene foam trays covered with PVC film and indicator sensor was attached to the inner side of packaging film. The pattern of color change in indicator sensor was monitored and compared with meat quality parameters viz. total volatile basic nitrogen, D-glucose, standard plate count and tyrosine value to correlate ability of indicator sensor for its suitability to predict the meat quality and storage life. Results: The indicator sensor changed its color from yellow to blue starting from margins during the storage period of 24 h at ambient temperature and this correlated well with changes in meat quality parameters. Conclusions: The indicator sensor can be used for real-time monitoring of meat quality as the color of indicator sensor changed from yellow to blue starting from margins when meat deteriorates with advancement of the storage period. Thus by observing the color of indicator sensor quality of meat and shelf life can be predicted. PMID:27047103

Physical and combustion properties of nonwoven fabrics produced from conventional and naturally colored cottons

USDA-ARS?s Scientific Manuscript database

A comparative study was conducted to identify the effects of processing parameters on physical and combustion properties of needlepunched (NP) and hydroentangled (H-E) nonwoven fabrics produced from fibers of a standard Mid-South white fiber cotton and a naturally colored brown fiber cotton. The fl...

Online Denoising Based on the Second-Order Adaptive Statistics Model.

PubMed

Yi, Sheng-Lun; Jin, Xue-Bo; Su, Ting-Li; Tang, Zhen-Yun; Wang, Fa-Fa; Xiang, Na; Kong, Jian-Lei

2017-07-20

Online denoising is motivated by real-time applications in the industrial process, where the data must be utilizable soon after it is collected. Since the noise in practical process is usually colored, it is quite a challenge for denoising techniques. In this paper, a novel online denoising method was proposed to achieve the processing of the practical measurement data with colored noise, and the characteristics of the colored noise were considered in the dynamic model via an adaptive parameter. The proposed method consists of two parts within a closed loop: the first one is to estimate the system state based on the second-order adaptive statistics model and the other is to update the adaptive parameter in the model using the Yule-Walker algorithm. Specifically, the state estimation process was implemented via the Kalman filter in a recursive way, and the online purpose was therefore attained. Experimental data in a reinforced concrete structure test was used to verify the effectiveness of the proposed method. Results show the proposed method not only dealt with the signals with colored noise, but also achieved a tradeoff between efficiency and accuracy.

On statistical analysis of factors affecting anthocyanin extraction from Ixora siamensis

NASA Astrophysics Data System (ADS)

Mat Nor, N. A.; Arof, A. K.

2016-10-01

This study focused on designing an experimental model in order to evaluate the influence of operative extraction parameters employed for anthocyanin extraction from Ixora siamensis on CIE color measurements (a*, b* and color saturation). Extractions were conducted at temperatures of 30, 55 and 80°C, soaking time of 60, 120 and 180 min using acidified methanol solvent with different trifluoroacetic acid (TFA) contents of 0.5, 1.75 and 3% (v/v). The statistical evaluation was performed by running analysis of variance (ANOVA) and regression calculation to investigate the significance of the generated model. Results show that the generated regression models adequately explain the data variation and significantly represented the actual relationship between the independent variables and the responses. Analysis of variance (ANOVA) showed high coefficient determination values (R2) of 0.9687 for a*, 0.9621 for b* and 0.9758 for color saturation, thus ensuring a satisfactory fit of the developed models with the experimental data. Interaction between TFA content and extraction temperature exhibited to the highest significant influence on CIE color parameter.

Automatic patient-adaptive bleeding detection in a capsule endoscopy

NASA Astrophysics Data System (ADS)

Jung, Yun Sub; Kim, Yong Ho; Lee, Dong Ha; Lee, Sang Ho; Song, Jeong Joo; Kim, Jong Hyo

2009-02-01

We present a method for patient-adaptive detection of bleeding region for a Capsule Endoscopy (CE) images. The CE system has 320x320 resolution and transmits 3 images per second to receiver during around 10-hour. We have developed a technique to detect the bleeding automatically utilizing color spectrum transformation (CST) method. However, because of irregular conditions like organ difference, patient difference and illumination condition, detection performance is not uniform. To solve this problem, the detection method in this paper include parameter compensation step which compensate irregular image condition using color balance index (CBI). We have investigated color balance through sequential 2 millions images. Based on this pre-experimental result, we defined ΔCBI to represent deviate of color balance compared with standard small bowel color balance. The ΔCBI feature value is extracted from each image and used in CST method as parameter compensation constant. After candidate pixels were detected using CST method, they were labeled and examined with a bleeding character. We tested our method with 4,800 images in 12 patient data set (9 abnormal, 3 normal). Our experimental results show the proposed method achieves (before patient adaptive method : 80.87% and 74.25%, after patient adaptive method : 94.87% and 96.12%) of sensitivity and specificity.

Optimization of Bleaching Parameters in Refining Process of Kenaf Seed Oil with a Central Composite Design Model.

PubMed

Chew, Sook Chin; Tan, Chin Ping; Nyam, Kar Lin

2017-07-01

Kenaf seed oil has been suggested to be used as nutritious edible oil due to its unique fatty acid composition and nutritional value. The objective of this study was to optimize the bleaching parameters of the chemical refining process for kenaf seed oil, namely concentration of bleaching earth (0.5 to 2.5% w/w), temperature (30 to 110 °C) and time (5 to 65 min) based on the responses of total oxidation value (TOTOX) and color reduction using response surface methodology. The results indicated that the corresponding response surface models were highly statistical significant (P < 0.0001) and sufficient to describe and predict TOTOX value and color reduction with R 2 of 0.9713 and 0.9388, respectively. The optimal parameters in the bleaching stage of kenaf seed oil were: 1.5% w/w of the concentration of bleaching earth, temperature of 70 °C, and time of 40 min. These optimum parameters produced bleached kenaf seed oil with TOTOX value of 8.09 and color reduction of 32.95%. There were no significant differences (P > 0.05) between experimental and predicted values, indicating the adequacy of the fitted models. © 2017 Institute of Food Technologists®.

Prediction of beef color using time-domain nuclear magnetic resonance (TD-NMR) relaxometry data and multivariate analyses.

PubMed

Moreira, Luiz Felipe Pompeu Prado; Ferrari, Adriana Cristina; Moraes, Tiago Bueno; Reis, Ricardo Andrade; Colnago, Luiz Alberto; Pereira, Fabíola Manhas Verbi

2016-05-19

Time-domain nuclear magnetic resonance and chemometrics were used to predict color parameters, such as lightness (L*), redness (a*), and yellowness (b*) of beef (Longissimus dorsi muscle) samples. Analyzing the relaxation decays with multivariate models performed with partial least-squares regression, color quality parameters were predicted. The partial least-squares models showed low errors independent of the sample size, indicating the potentiality of the method. Minced procedure and weighing were not necessary to improve the predictive performance of the models. The reduction of transverse relaxation time (T 2 ) measured by Carr-Purcell-Meiboom-Gill pulse sequence in darker beef in comparison with lighter ones can be explained by the lower relaxivity Fe 2+ present in deoxymyoglobin and oxymyoglobin (red beef) to the higher relaxivity of Fe 3+ present in metmyoglobin (brown beef). These results point that time-domain nuclear magnetic resonance spectroscopy can become a useful tool for quality assessment of beef cattle on bulk of the sample and through-packages, because this technique is also widely applied to measure sensorial parameters, such as flavor, juiciness and tenderness, and physicochemical parameters, cooking loss, fat and moisture content, and instrumental tenderness using Warner Bratzler shear force. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Changes in quality and biochemical parameters in 'Idared' apples during prolonged shelf life and 1-MCP treatment.

PubMed

Bizjak, Jan; Slatnar, Ana; Stampar, Franci; Veberic, Robert

2012-12-01

In this study, changes in quality and various biochemical parameters of 'Idared' apples during prolonged shelf life period after ultra-low oxygen (ULO) storage were investigated. Additionally, the impact of the postharvest application of 1-methylcyclopropene (1-MCP) on different parameters was evaluated. After the harvest, apples were stored in the ULO storage for 6 months and then exposed to room temperature. Fruit firmness, peel color, and changes in sugars, organic acids and phenolics were monitored during the 3 weeks of shelf life. Malic acid, sugars and firmness decreased at room temperature. However, the color of the apples remained unchanged. The level of citric and ascorbic acid remained constant. Levels of phenolics in the peel increased significantly, whereas remained constant in the pulp of apples. 1-MCP treatment resulted in higher amounts of fructose and glucose, malic acid and greater firmness of apples. However, 1-MCP did not influence the phenolic content, ascorbic acid or color. The results obtained indicate that the content of different health-promoting compounds of apples does not change dramatically at room temperature. At the same time these results suggest that 1-MCP could be useful for maintaining certain quality and biochemical parameters and might extend the shelf life of apples.

Construction of general colored R matrices for the Yang-Baxter equation and q-boson realization of quantum algebra SL[sub q](2) when q is a root of unity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ge, M.L.; Sun, C.P.; Xue, K.

1992-10-20

In this paper, through a general q-boson realization of quantum algebra sl[sub q](2) and its universal R matrix an operator R matrix with many parameters is obtained in terms of q-boson operators. Building finite-dimensional representations of q-boson algebra, the authors construct various colored R matrices associated with nongeneric representations of sl[sub q](2) with dimension-independent parameters. The nonstandard R matrices obtained by Lee-Couture and Murakami are their special examples.

Assessment of color parameters of composite resin shade guides using digital imaging versus colorimeter.

PubMed

Yamanel, Kivanc; Caglar, Alper; Özcan, Mutlu; Gulsah, Kamran; Bagis, Bora

2010-12-01

This study evaluated the color parameters of resin composite shade guides determined using a colorimeter and digital imaging method. Four composite shade guides, namely: two nanohybrid (Grandio [Voco GmbH, Cuxhaven, Germany]; Premise [KerrHawe SA, Bioggio, Switzerland]) and two hybrid (Charisma [Heraeus Kulzer, GmbH & Co. KG, Hanau, Germany]; Filtek Z250 [3M ESPE, Seefeld, Germany]) were evaluated. Ten shade tabs were selected (A1, A2, A3, A3,5, A4, B1, B2, B3, C2, C3) from each shade guide. CIE Lab values were obtained using digital imaging and a colorimeter (ShadeEye NCC Dental Chroma Meter, Shofu Inc., Kyoto, Japan). The data were analyzed using two-way analysis of variance and Bonferroni post hoc test. Overall, the mean ΔE values from different composite pairs demonstrated statistically significant differences when evaluated with the colorimeter (p < 0.001) but there was no significant difference with the digital imaging method (p = 0.099). With both measurement methods in total, 80% of the shade guide pairs from different composites (97/120) showed color differences greater than 3.7 (moderately perceptible mismatch), and 49% (59/120) had obvious mismatch (ΔE > 6.8). For all shade pairs evaluated, the most significant shade mismatches were obtained between Grandio-Filtek Z250 (p = 0.021) and Filtek Z250-Premise (p = 0.01) regarding ΔE mean values, whereas the best shade match was between Grandio-Charisma (p = 0.255) regardless of the measurement method. The best color match (mean ΔE values) was recorded for A1, A2, and A3 shade pairs in both methods. When proper object-camera distance, digital camera settings, and suitable illumination conditions are provided, digital imaging method could be used in the assessment of color parameters. Interchanging use of shade guides from different composite systems should be avoided during color selection. © 2010, COPYRIGHT THE AUTHORS. JOURNAL COMPILATION © 2010, WILEY PERIODICALS, INC.

Carded Tow Real-Time Color Assessment: A Spectral Camera-Based System.

PubMed

Furferi, Rocco; Governi, Lapo; Volpe, Yary; Carfagni, Monica

2016-08-31

One of the most important parameters to be controlled during the production of textile yarns obtained by mixing pre-colored fibers, is the color correspondence between the manufactured yarn and a given reference, usually provided by a designer or a customer. Obtaining yarns from raw pre-colored fibers is a complex manufacturing process entailing a number of steps such as laboratory sampling, color recipe corrections, blowing, carding and spinning. Carding process is the one devoted to transform a "fuzzy mass" of tufted fibers into a regular mass of untwisted fibers, named "tow". During this process, unfortunately, the correspondence between the color of the tow and the target one cannot be assured, thus leading to yarns whose color differs from the one used for reference. To solve this issue, the main aim of this work is to provide a system able to perform a spectral camera-based real-time measurement of a carded tow, to assess its color correspondence with a reference carded fabric and, at the same time, to monitor the overall quality of the tow during the carding process. Tested against a number of differently colored carded fabrics, the proposed system proved its effectiveness in reliably assessing color correspondence in real-time.

Art in a new light: Design and assessment of illuminants to reduce photochemical degradation of works of art

NASA Astrophysics Data System (ADS)

Delgado Ramos, Monica Fabiola

The purpose of this research is to design the best lighting that will minimize long term photochemical degradation of Old Master Drawings and/or other works of art, while maintaining the patron's appreciation of the object's color and detail. The present approach is a technological refinement to the basic underlying earlier work on fluorescent lighting by W. A. Thornton, W.A. at General Electric1. Thin-film dielectric, multi-coating technology is used to create filters that eliminate ultraviolet light, near infrared light and significant unnecessary parts from the visible spectrum, thus maximizing the reduction in photochemical degradation, while maintaining optimal color rendering. Three interference filters, were designed and manufactured successfully. The filters are designated Mark 1, Mark 2, & Mark 3. In this dissertation, the filters are analyzed with regard to their performance parameters. This includes color rendering, retardation in fading or color change, beam angle effects, filter stability, perceived brightness, and visual appreciation parameters. To a high confidence level, all three filters are perceived as being indistinguishable from Unfiltered light with regard to the color confusion index parameter (CCI). Subjective assessments by tests subjects suggest the Mark 3 filter may display some distinguishability with a confidence level for distinguishability of 35% for the overall satisfaction parameter. The Mark 3 filter is the most complex three-color type spectral profile and this might be expected due to beam angle effects or departures in accuracy of color theory. Beam angle affects suggest that the Mark 1 and Mark 2 filters do not display significant color rendering aberrations due to Newton's colors interference effects, except possibly at the periphery of the broadest (55-60+°) beam angle lamps. Filtered and Unfiltered light are effectively of the same perceived brightness, though to a low confidence level, Unfiltered light might be perceived brighter. Accelerated aging studies of the filters indicate useful mean time before failures of >20 years. In fact, no failure was observed in any of the accelerated studies, The Mark 2 and Mark 3 filters were evaluated in equal-luminosity studies with regard to their effect on limiting fading of both standard fading samples such as the ISO Blue Wool series, and also other commercial pigments or stains. Within experimental error, the Mark 2 filter either slowed fading or had no effect on fading for all pigments relative to Unfiltered light and OptivexRTM filtered light, OptivexRTM being a common commercial filter used to protect works of art. Mark 3 protected in many cases, but for some pigments it was less protective than OptivexRTM filtered light. This failure is interpreted in terms of the wavelength dependence of the excess light in certain wavelength regions on an equal luminosity condition, and suggests that more subtle wavelength dependent optimizations have to be undertaken for filters which possess significant band separation.

Comparative sensory and proximate evaluation of spontaneously fermenting kunu-zaki made from germinated and ungerminated composite cereal grains

PubMed Central

Oluwajoba, Solakunmi O; Akinyosoye, Felix A; Oyetayo, Olusegun V

2013-01-01

This study evaluated the sensory properties, proximate composition, and overall consumer acceptability of kunu-zaki using germinated and ungerminated Sorghum bicolor (sorghum), Pennisetum americanum (millet), and Digitaria exilis (acha) cereal grains. The three cereal grains were used in nongerminated and germinated composite and noncomposite proportions coded A (Acha), S (Sorghum), M (Millet), AS (Acha–Sorghum), AM (Acha–Millet), SM (Sorghum–Millet), ASG (Acha–Sorghum Germinated), AMG (Acha–Millet Germinated), and SMG (Sorghum–Millet Germinated). Proximate analysis determined the moisture content, ash, crude fiber, fat, and crude protein content of the fermented grains. The 9-point hedonic scale was used to judge the sensory parameters of taste, color, and aroma. The paired comparison test was used to judge consumer preference between kunu-zaki made from germinated grains and the ungerminated counterpart. Scores were statistically analyzed using the Kruskal–Wallis test in the SPSS analytical software package. Panelists ranked the ASG-coded drink highest in terms of taste and aroma, the AMG-coded drink highest in terms of color. SM ranked least in terms of taste; SMG ranked least in terms of aroma; and AM ranked the least in terms of color. Preference for each parameter was significantly different (P < 0.001). Panelists ranked overall preference for the drinks from the most liked to the least liked in the order ASG>AMG>A>AS>S>M>SMG>AM>SM. The overall preference for the drinks was also significantly different (P < 0.001). Panelists pairing both ungerminated drinks with the germinated drinks ranked the ungerminated drink AS as most preferred in terms of taste, color, and aroma above its germinated counterpart ASG with preference not significantly dependent on the parameters (P = 0.065 > 0.05). Ungerminated AM was also preferred above the germinated counterpart AMG in terms of taste, color, and aroma with preference not significantly dependent on parameters (P = 0.055 > 0.05). However, panelists showed preference for the taste and aroma of the germinated drink SMG but more preference for the color of the ungerminated drink SM with preference significantly dependent on the parameters (P = 0.028 < 0.05). Crude fiber values were higher – 11.3%, 13.1%, and 17.37% for SMG, AMG and ASG, respectively. Germination increased %Fat values slightly but the %Ash was relatively stable in both germinated and ungerminated drinks. Addition of germinated acha cereal grains to either sorghum or millet prior to fermentation offers desirable sensory and nutritional quality attributes in kunu-zaki. PMID:24804038

Comparative sensory and proximate evaluation of spontaneously fermenting kunu-zaki made from germinated and ungerminated composite cereal grains.

PubMed

Oluwajoba, Solakunmi O; Akinyosoye, Felix A; Oyetayo, Olusegun V

2013-07-01

This study evaluated the sensory properties, proximate composition, and overall consumer acceptability of kunu-zaki using germinated and ungerminated Sorghum bicolor (sorghum), Pennisetum americanum (millet), and Digitaria exilis (acha) cereal grains. The three cereal grains were used in nongerminated and germinated composite and noncomposite proportions coded A (Acha), S (Sorghum), M (Millet), AS (Acha-Sorghum), AM (Acha-Millet), SM (Sorghum-Millet), ASG (Acha-Sorghum Germinated), AMG (Acha-Millet Germinated), and SMG (Sorghum-Millet Germinated). Proximate analysis determined the moisture content, ash, crude fiber, fat, and crude protein content of the fermented grains. The 9-point hedonic scale was used to judge the sensory parameters of taste, color, and aroma. The paired comparison test was used to judge consumer preference between kunu-zaki made from germinated grains and the ungerminated counterpart. Scores were statistically analyzed using the Kruskal-Wallis test in the SPSS analytical software package. Panelists ranked the ASG-coded drink highest in terms of taste and aroma, the AMG-coded drink highest in terms of color. SM ranked least in terms of taste; SMG ranked least in terms of aroma; and AM ranked the least in terms of color. Preference for each parameter was significantly different (P < 0.001). Panelists ranked overall preference for the drinks from the most liked to the least liked in the order ASG>AMG>A>AS>S>M>SMG>AM>SM. The overall preference for the drinks was also significantly different (P < 0.001). Panelists pairing both ungerminated drinks with the germinated drinks ranked the ungerminated drink AS as most preferred in terms of taste, color, and aroma above its germinated counterpart ASG with preference not significantly dependent on the parameters (P = 0.065 > 0.05). Ungerminated AM was also preferred above the germinated counterpart AMG in terms of taste, color, and aroma with preference not significantly dependent on parameters (P = 0.055 > 0.05). However, panelists showed preference for the taste and aroma of the germinated drink SMG but more preference for the color of the ungerminated drink SM with preference significantly dependent on the parameters (P = 0.028 < 0.05). Crude fiber values were higher - 11.3%, 13.1%, and 17.37% for SMG, AMG and ASG, respectively. Germination increased %Fat values slightly but the %Ash was relatively stable in both germinated and ungerminated drinks. Addition of germinated acha cereal grains to either sorghum or millet prior to fermentation offers desirable sensory and nutritional quality attributes in kunu-zaki.

A mathematical analysis of the ABCD criteria for diagnosing malignant melanoma

NASA Astrophysics Data System (ADS)

Lee, Hyunju; Kwon, Kiwoon

2017-03-01

The medical community currently employs the ABCD (asymmetry, border irregularity, color variegation, and diameter of the lesion) criteria in the early diagnosis of a malignant melanoma. Although many image segmentation and classification methods are used to analyze the ABCD criteria, it is rare to see a study containing mathematical justification of the parameters that are used to quantify the ABCD criteria. In this paper, we suggest new parameters to assess asymmetry, border irregularity, and color variegation, and explain the mathematical meaning of the parameters. The suggested parameters are then tested with 24 skin samples. The parameters suggested for the 24 skin samples are displayed in three-dimensional coordinates and are compared to those presented in other studies (Ercal et al 1994 IEEE Trans. Biomed. Eng. 41 837-45, Cheerla and Frazier 2014 Int. J. Innovative Res. Sci., Eng. Technol. 3 9164-83) in terms of Pearson correlation coefficient and classification accuracy in determining the malignancy of the lesions.

Reanalyzing the visible colors of Centaurs and KBOs: what is there and what we might be missing

NASA Astrophysics Data System (ADS)

Peixinho, Nuno; Delsanti, Audrey; Doressoundiram, Alain

2015-05-01

Since the discovery of the Kuiper belt, broadband surface colors were thoroughly studied as a first approximation to the object reflectivity spectra. Visible colors (BVRI) have proven to be a reasonable proxy for real spectra, which are rather linear in this range. In contrast, near-IR colors (JHK bands) could be misleading when absorption features of ices are present in the spectra. Although the physical and chemical information provided by colors are rather limited, broadband photometry remains the best tool for establishing the bulk surface properties of Kuiper belt objects (KBOs) and Centaurs. In this work, we explore for the first time general, recurrent effects in the study of visible colors that could affect the interpretation of the scientific results: i) how a correlation could be missed or weakened as a result of the data error bars; ii) the "risk" of missing an existing trend because of low sampling, and the possibility of making quantified predictions on the sample size needed to detect a trend at a given significance level - assuming the sample is unbiased; iii) the use of partial correlations to distinguish the mutual effect of two or more (physical) parameters; and iv) the sensitivity of the "reddening line" tool to the central wavelength of the filters used. To illustrate and apply these new tools, we have compiled the visible colors and orbital parameters of about 370 objects available in the literature - assumed, by default, as unbiased samples - and carried out a traditional analysis per dynamical family. Our results show in particular how a) data error bars impose a limit on the detectable correlations regardless of sample size and that therefore, once that limit is achieved, it is important to diminish the error bars, but it is pointless to enlarge the sampling with the same or larger errors; b) almost all dynamical families still require larger samplings to ensure the detection of correlations stronger than ±0.5, that is, correlations that may explain ~25% or more of the color variability; c) the correlation strength between (V - R) vs. (R - I) is systematically lower than the one between (B - V) vs. (V - R) and is not related with error-bar differences between these colors; d) it is statistically equivalent to use any of the different flavors of orbital excitation or collisional velocity parameters regarding the famous color-inclination correlation among classical KBOs - which no longer appears to be a strong correlation - whereas the inclination and Tisserand parameter relative to Neptune cannot be separated from one another; and e) classical KBOs are the only dynamical family that shows neither (B - V) vs. (V - R) nor (V - R) vs. (R - I) correlations. It therefore is the family with the most unpredictable visible surface reflectivities. Tables 4 and 5 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/577/A35

Simulation of multicomponent light source for optical-electronic system of color analysis objects

NASA Astrophysics Data System (ADS)

Peretiagin, Vladimir S.; Alekhin, Artem A.; Korotaev, Valery V.

2016-04-01

Development of lighting technology has led to possibility of using LEDs in the specialized devices for outdoor, industrial (decorative and accent) and domestic lighting. In addition, LEDs and devices based on them are widely used for solving particular problems. For example, the LED devices are widely used for lighting of vegetables and fruit (for their sorting or growing), textile products (for the control of its quality), minerals (for their sorting), etc. Causes of active introduction LED technology in different systems, including optical-electronic devices and systems, are a large choice of emission color and LED structure, that defines the spatial, power, thermal and other parameters. Furthermore, multi-element and color devices of lighting with adjustable illumination properties can be designed and implemented by using LEDs. However, devices based on LEDs require more attention if you want to provide a certain nature of the energy or color distribution at all the work area (area of analysis or observation) or surface of the object. This paper is proposed a method of theoretical modeling of the lighting devices. The authors present the models of RGB multicomponent light source applied to optical-electronic system for the color analysis of mineral objects. The possibility of formation the uniform and homogeneous on energy and color illumination of the work area for this system is presented. Also authors showed how parameters and characteristics of optical radiation receiver (by optical-electronic system) affect on the energy, spatial, spectral and colorimetric properties of a multicomponent light source.

Polarization-sensitive color in butterfly scales: polarization conversion from ridges with reflecting elements.

PubMed

Zhang, Ke; Tang, Yiwen; Meng, Jinsong; Wang, Ge; Zhou, Han; Fan, Tongxiang; Zhang, Di

2014-11-03

Polarization-sensitive color originates from polarization-dependent reflection or transmission, exhibiting abundant light information, including intensity, spectral distribution, and polarization. A wide range of butterflies are physiologically sensitive to polarized light, but the origins of polarized signal have not been fully understood. Here we systematically investigate the colorful scales of six species of butterfly to reveal the physical origins of polarization-sensitive color. Microscopic optical images under crossed polarizers exhibit their polarization-sensitive characteristic, and micro-structural characterizations clarify their structural commonality. In the case of the structural scales that have deep ridges, the polarization-sensitive color related with scale azimuth is remarkable. Periodic ridges lead to the anisotropic effective refractive indices in the parallel and perpendicular grating orientations, which achieves form-birefringence, resulting in the phase difference of two different component polarized lights. Simulated results show that ridge structures with reflecting elements reflect and rotate the incident p-polarized light into s-polarized light. The dimensional parameters and shapes of grating greatly affect the polarization conversion process, and the triangular deep grating extends the outstanding polarization conversion effect from the sub-wavelength period to the period comparable to visible light wavelength. The parameters of ridge structures in butterfly scales have been optimized to fulfill the polarization-dependent reflection for secret communication. The structural and physical origin of polarization conversion provides a more comprehensive perspective on the creation of polarization-sensitive color in butterfly wing scales. These findings show great potential in anti-counterfeiting technology and advanced optical material design.

Objective Measurement of Erythema in Psoriasis using Digital Color Photography with Color Calibration

PubMed Central

Raina, Abhay; Hennessy, Ricky; Rains, Michael; Allred, James; Hirshburg, Jason M; Diven, Dayna; Markey, Mia K.

2016-01-01

Background Traditional metrics for evaluating the severity of psoriasis are subjective, which complicates efforts to measure effective treatments in clinical trials. Methods We collected images of psoriasis plaques and calibrated the coloration of the images according to an included color card. Features were extracted from the images and used to train a linear discriminant analysis classifier with cross-validation to automatically classify the degree of erythema. The results were tested against numerical scores obtained by a panel of dermatologists using a standard rating system. Results Quantitative measures of erythema based on the digital color images showed good agreement with subjective assessment of erythema severity (κ = 0.4203). The color calibration process improved the agreement from κ = 0.2364 to κ = 0.4203. Conclusions We propose a method for the objective measurement of the psoriasis severity parameter of erythema and show that the calibration process improved the results. PMID:26517973

Visual long-term memory has the same limit on fidelity as visual working memory.

PubMed

Brady, Timothy F; Konkle, Talia; Gill, Jonathan; Oliva, Aude; Alvarez, George A

2013-06-01

Visual long-term memory can store thousands of objects with surprising visual detail, but just how detailed are these representations, and how can one quantify this fidelity? Using the property of color as a case study, we estimated the precision of visual information in long-term memory, and compared this with the precision of the same information in working memory. Observers were shown real-world objects in random colors and were asked to recall the colors after a delay. We quantified two parameters of performance: the variability of internal representations of color (fidelity) and the probability of forgetting an object's color altogether. Surprisingly, the fidelity of color information in long-term memory was comparable to the asymptotic precision of working memory. These results suggest that long-term memory and working memory may be constrained by a common limit, such as a bound on the fidelity required to retrieve a memory representation.

Color representation and interpretation of special effect coatings.

PubMed

Ferrero, A; Perales, E; Rabal, A M; Campos, J; Martínez-Verdú, F M; Chorro, E; Pons, A

2014-02-01

A representation of the color gamut of special effect coatings is proposed and shown for six different samples, whose colors were calculated from spectral bidirectional reflectance distribution function (BRDF) measurements at different geometries. The most important characteristic of the proposed representation is that it allows a straightforward understanding of the color shift to be done both in terms of conventional irradiation and viewing angles and in terms of flake-based parameters. A different line was proposed to assess the color shift of special effect coatings on a*,b*-diagrams: the absorption line. Similar to interference and aspecular lines (constant aspecular and irradiation angles, respectively), an absorption line is the locus of calculated color coordinates from measurement geometries with a fixed bistatic angle. The advantages of using the absorption lines to characterize the contributions to the spectral BRDF of the scattering at the absorption pigments and the reflection at interference pigments for different geometries are shown.

Color management of porcelain veneers: influence of dentin and resin cement colors.

PubMed

Dozic, Alma; Tsagkari, Maria; Khashayar, Ghazal; Aboushelib, Moustafa

2010-01-01

Porcelain veneers have become an interesting treatment option to correct the shape and color of anterior teeth. Because of their limited thickness and high translucency, achieving a good color match is influenced by several variables. The aim of this work was to investigate the influence of natural dentin and resin cement colors on final color match of porcelain veneers. A preselected shade tab (A1) was chosen as the target color for a maxillary central incisor, and its color parameters (L*a*b*) were measured using a digital spectrophotometer (SpectroShade, MHT). Nine natural dentin colors (Natural Die Material, Ivoclar Vivadent) representing a wide range of tooth colors were used to prepare resin replicas of the maxillary central incisor with a standard preparation for porcelain veneers. The prepared porcelain veneers (IPS Empress Esthetic, A1, 0.6 mm thick, Ivoclar Vivadent) were cemented on the resin dies (nine groups of natural dentin colors) using seven shades of resin cement (Variolink Veneers, Ivoclar Vivadent). The L*a*b* values of the cemented veneers were measured, and DE values were calculated against the preselected target color (A1). DE greater than 3.3 was considered as a significant color mismatch detectable by the human eye. The seven shades of resin cement had no significant influence on the final color of the veneers, as the measured DE values were almost identical for every test group. On the other hand, the color of natural dentin was a significant factor that influenced final color match. None of the 63 tested combinations (nine natural dentin colors and seven resin cement colors) produced an acceptable color match. Thin porcelain veneers cannot mask underlying tooth color even when different shades of resin cement are used. Incorporation of opaque porcelain (high chroma) may improve final color match.

Dome diagnostics system of optical parameters and characteristics of LEDs

NASA Astrophysics Data System (ADS)

Peretyagin, Vladimir S.; Pavlenko, Nikita A.

2017-09-01

Scientific and technological progress of recent years in the production of the light emitting diodes (LEDs) has led to the expansion of areas of their application from the simplest systems to high precision lighting devices used in various fields of human activity. However, development and production (especially mass production) of LED lighting devices are impossible without a thorough analysis of its parameters and characteristics. There are many ways and devices for analysis the spatial, energy and colorimetric parameters of LEDs. The most methods are intended for definition only one parameter (for example, luminous flux) or one characteristic (for example, the angular distribution of energy or the spectral characteristics). Besides, devices used these methods are intended for measuring parameters in only one point or plane. This problem can be solved by using a dome diagnostics system of optical parameters and characteristics of LEDs, developed by specialists of the department OEDS chair of ITMO University in Russia. The paper presents the theoretical aspects of the analysis of LED's spatial (angular), energy and color parameters by using mentioned of diagnostics system. The article also presents the results of spatial), energy and color parameters measurements of some LEDs brands.

Influence of red jersey color on physical parameters in combat sports.

PubMed

Dreiskaemper, Dennis; Strauss, Bernd; Hagemann, Norbert; Büsch, Dirk

2013-02-01

Hill and Barton (2005) showed that fighters in tae kwon do, boxing, and wrestling who wore red jerseys during the 2004 Olympic Games won more often than those wearing blue jerseys. Regarding these results, this study investigated the effects of jersey color during a combat situation on fighters' physical parameters of strength and heart rate. An artificial, experimental combat situation was created in which the color of sport attire was assigned randomly. Fourteen pairs of male athletes matched for weight, height, and age had to fight each other: once in a red jersey and once in a blue. Heart rate (before, during, and after the fight) and strength (before the fight) were tested wearing the blue and the red jerseys. Participants wearing red jerseys had significantly higher heart rates and significantly higher pre-contest values on the strength test. Results showed that participants' body functions are influenced by wearing red equipment.

Estimating extinction using unsupervised machine learning

NASA Astrophysics Data System (ADS)

Meingast, Stefan; Lombardi, Marco; Alves, João

2017-05-01

Dust extinction is the most robust tracer of the gas distribution in the interstellar medium, but measuring extinction is limited by the systematic uncertainties involved in estimating the intrinsic colors to background stars. In this paper we present a new technique, Pnicer, that estimates intrinsic colors and extinction for individual stars using unsupervised machine learning algorithms. This new method aims to be free from any priors with respect to the column density and intrinsic color distribution. It is applicable to any combination of parameters and works in arbitrary numbers of dimensions. Furthermore, it is not restricted to color space. Extinction toward single sources is determined by fitting Gaussian mixture models along the extinction vector to (extinction-free) control field observations. In this way it becomes possible to describe the extinction for observed sources with probability densities, rather than a single value. Pnicer effectively eliminates known biases found in similar methods and outperforms them in cases of deep observational data where the number of background galaxies is significant, or when a large number of parameters is used to break degeneracies in the intrinsic color distributions. This new method remains computationally competitive, making it possible to correctly de-redden millions of sources within a matter of seconds. With the ever-increasing number of large-scale high-sensitivity imaging surveys, Pnicer offers a fast and reliable way to efficiently calculate extinction for arbitrary parameter combinations without prior information on source characteristics. The Pnicer software package also offers access to the well-established Nicer technique in a simple unified interface and is capable of building extinction maps including the Nicest correction for cloud substructure. Pnicer is offered to the community as an open-source software solution and is entirely written in Python.

Daytime Changes of Skin Biophysical Characteristics: A Study of Hydration, Transepidermal Water Loss, pH, Sebum, Elasticity, Erythema, and Color Index on Middle Eastern Skin

PubMed Central

Firooz, Alireza; Zartab, Hamed; Sadr, Bardia; Bagherpour, Leili Naraghi; Masoudi, Aidin; Fanian, Ferial; Dowlati, Yahya; Ehsani, Amir Hooshang; Samadi, Aniseh

2016-01-01

Background: The exposure of skin to ultraviolet radiation and temperature differs significantly during the day. It is reasonable that biophysical parameters of human skin have periodic daily fluctuation. The objective of this study was to study the fluctuations of various biophysical characteristics of Middle Eastern skin in standardized experimental conditions. Materials and Methods: Seven biophysical parameters of skin including stratum corneum hydration, transepidermal water loss, pH, sebum, elasticity, skin color, and erythema index were measured at three time points (8 a.m., 12 p.m. and 4 p.m.) on the forearm of 12 healthy participants (mean age of 28.4 years) without any ongoing skin disease using the CK MPA 580 device in standard temperature and humidity conditions. Results: A significant difference was observed between means of skin color index at 8 a.m. (175.42 ± 13.92) and 4 p.m. (164.44 ± 13.72, P = 0.025), between the pH at 8 a.m. (5.72 ± 0.48) and 4 p.m. (5.33 ± 0.55, P = 0.001) and pH at 12 p.m. (5.60 ± 0.48) and 4 p.m. (5.33 ± 0.55, P = 0.001). Other comparisons between the means of these parameters at different time points resulted in nonsignificant P values. Conclusion: There are daytime changes in skin color index and pH. Skin color index might be higher and cutaneous pH more basic in the early morning compared to later of the day. PMID:27904203

Fabry-Perot color filter with antireflective nano-grating surface

NASA Astrophysics Data System (ADS)

Zhang, Jiayuan; Zhang, Jie; Dong, Xiaoxuan

2013-12-01

In order to improve the color saturation of reflective Fabry-Perot(FP) color filter, we proposed a reflective color filter incorporating FP resonator with a dielectric grating. The FP resonator consists of high reflection metal film, dielectric film and semi-transparent metal film. The dielectric grating, above the semi-transparent metal film, can reduce the reflection from the semi-transparent film in which case high saturation will be achieved. By using Finite Difference Time Domain(FDTD) method, the reflection spectra characteristic is analyzed as a function of duty cycle, period, refractive index and thickness of the dielectric grating. Based on the simulation results, a high performance color filter is proposed by optimizing the structural parameters. The full width at half-maximum (FWHM) reflection spectrum of the filters are reduced from 100 nm to 70 nm and the peak reflection efficiency of the filters are about 90%. The overlap of the tricolor output spectra decreases effectively, which will increase the color saturation of the color filter.

Skin Color Segmentation Using Coarse-to-Fine Region on Normalized RGB Chromaticity Diagram for Face Detection

NASA Astrophysics Data System (ADS)

Soetedjo, Aryuanto; Yamada, Koichi

This paper describes a new color segmentation based on a normalized RGB chromaticity diagram for face detection. Face skin is extracted from color images using a coarse skin region with fixed boundaries followed by a fine skin region with variable boundaries. Two newly developed histograms that have prominent peaks of skin color and non-skin colors are employed to adjust the boundaries of the skin region. The proposed approach does not need a skin color model, which depends on a specific camera parameter and is usually limited to a particular environment condition, and no sample images are required. The experimental results using color face images of various races under varying lighting conditions and complex backgrounds, obtained from four different resources on the Internet, show a high detection rate of 87%. The results of the detection rate and computation time are comparable to the well known real-time face detection method proposed by Viola-Jones [11], [12].

Features of color reflection in psychogenic pain in patients with somatoform disorders during psychotherapeutic treatment.

PubMed

Ishinova, Vera A; Svyatogor, Irina A; Reznikova, Tatiana N

2009-11-01

The present work examines the change in color reflection in psychogenic pain in patients with somatoform disorders (SFD) during psychotherapeutic treatment, for which empatho-techniques were used. At the start and end of the course the psychophysiological condition was determined according to psychological parameters and assessment of bioelectrical brain activity. All initial indicators for the patients significantly differed from those for the healthy subjects. At the same time, color reflection in the psychogenic pain was characterised by colors in the longwave part of the spectrum, in contradistinction to healthy subjects for whom achromatic and shortwave colors predominated. After the completed course patients with SFD had a significant improvement of all psychophysiological indicators and a lack of color reflectons in the longwave part of the spectrum. The data obtained permits the proposition that there exists a link between the psychogenic pain, its color reflection and anxiety, and also changes in the functional condition of the CNS.

Correlations among Galaxy Properties from the Sloan Digital Sky Survey

NASA Astrophysics Data System (ADS)

Li, Zhongmu; Mao, Caiyan

2013-07-01

Galaxies are complex systems with many properties. Correlations among galaxy properties can supply important clues for studying the formation and evolution of galaxies. Using principal component analysis and least-squares fitting, this paper investigates the correlations among galactic parameters involving more properties (color, morphology, stellar population, and absolute magnitude) than previous studies. We use a volume-limited sample (whole sample) of 75,423 galaxies that was selected from the Sloan Digital Sky Survey Data Release 2 and divided into two subsamples (blue and red samples) using a critical color of (g - r) = 0.70 mag. In addition to recovering some previous results, we also obtain some new results. First, all separators for dividing galaxies into two groups can be related via good parameter-first principal component (PC1) correlations. A critical PC1 that indicates whether or not stellar age (or the evolution of a stellar population over time) is important can be used to separate galaxies. This suggests that a statistical parameter, PC1, is helpful in understanding the physical separators of galaxies. In addition, stellar age is shown to be unimportant for red galaxies, while both stellar age and mass are dominating parameters of blue galaxies. This suggests that the various numbers of dominating parameters of galaxies may result from the use of different samples. Finally, some parameters are shown to be correlated, and quantitative fits for a few correlations are obtained, e.g., log(t) = 8.57 + 1.65 (g - r) for the age (log t) and color (g - r) of blue galaxies and log (M *) = 4.31 - 0.30 M r for the stellar mass (log M *) and absolute magnitude (M r) of red galaxies. The median relationships between various parameter pairs are also presented for comparison.

Decoding and reconstructing color from responses in human visual cortex.

PubMed

Brouwer, Gijs Joost; Heeger, David J

2009-11-04

How is color represented by spatially distributed patterns of activity in visual cortex? Functional magnetic resonance imaging responses to several stimulus colors were analyzed with multivariate techniques: conventional pattern classification, a forward model of idealized color tuning, and principal component analysis (PCA). Stimulus color was accurately decoded from activity in V1, V2, V3, V4, and VO1 but not LO1, LO2, V3A/B, or MT+. The conventional classifier and forward model yielded similar accuracies, but the forward model (unlike the classifier) also reliably reconstructed novel stimulus colors not used to train (specify parameters of) the model. The mean responses, averaged across voxels in each visual area, were not reliably distinguishable for the different stimulus colors. Hence, each stimulus color was associated with a unique spatially distributed pattern of activity, presumably reflecting the color selectivity of cortical neurons. Using PCA, a color space was derived from the covariation, across voxels, in the responses to different colors. In V4 and VO1, the first two principal component scores (main source of variation) of the responses revealed a progression through perceptual color space, with perceptually similar colors evoking the most similar responses. This was not the case for any of the other visual cortical areas, including V1, although decoding was most accurate in V1. This dissociation implies a transformation from the color representation in V1 to reflect perceptual color space in V4 and VO1.

Constraining Dust and Color Variations of High-z SNe Using NICMOS on the

Science.gov Websites

Hubble SAO/NASA ADS Astronomy Abstract Service Title: Constraining Dust and Color Variations of Road, Oxford OX1 3RH, UK), AN(Department of Astronomy and Astrophysics, University of Toronto, 60 St ). Publication Date: 08/2009 Origin: IOP Astronomy Keywords: cosmology: observations, cosmological parameters

Differentiation of Wines Treated with Wood Chips Based on Their Phenolic Content, Volatile Composition, and Sensory Parameters.

PubMed

Kyraleou, Maria; Kallithraka, Stamatina; Chira, Kleopatra; Tzanakouli, Eleni; Ligas, Ioannis; Kotseridis, Yorgos

2015-12-01

The effects of both wood chips addition and contact time on phenolic content, volatile composition, color parameters, and organoleptic character of red wine made by a native Greek variety (Agiorgitiko) were evaluated. For this purpose, chips from American, French, Slavonia oak, and Acacia were added in the wine after fermentation. A mixture consisting of 50% French and 50% Americal oak chips was also evaluated. In an attempt to categorize wine samples, various chemical parameters of wines and sensory parameters were studied after 1, 2, and 3 mo of contact time with chips. The results showed that regardless of the type of wood chips added in the wines, it was possible to differentiate the samples according to the contact time based on their phenolic composition and color parameters. In addition, wood-extracted volatile compounds seem to be the critical parameter that could separate the samples according to the wood type. The wines that were in contact with Acacia and Slavonia chips could be separated from the rest mainly due to their distinct sensory characters. © 2015 Institute of Food Technologists®

The concept of physical surface in nuclear matter

NASA Astrophysics Data System (ADS)

Mazilu, Nicolae; Agop, Maricel

2015-02-01

The main point of a physical definition of surface forces in the matter in general, especially in the nuclear matter, is that the curvature of surfaces and its variation should be physically defined. The forces are therefore just the vehicles of introducing physics. The problem of mathematical definition of a surface in term of the curvature parameters thus naturally occurs. The present work addresses this problem in terms of the asymptotic directions of a surface in a point. A physical meaning of these parameters is given, first in terms of inertial forces, then in terms of a differential theory of colors, whereby the space of curvature parameters is identified with the color space. The work concludes with an image of the evolution of a local portion of a surface.

Spectral colors capture and reproduction based on digital camera

NASA Astrophysics Data System (ADS)

Chen, Defen; Huang, Qingmei; Li, Wei; Lu, Yang

2018-01-01

The purpose of this work is to develop a method for the accurate reproduction of the spectral colors captured by digital camera. The spectral colors being the purest color in any hue, are difficult to reproduce without distortion on digital devices. In this paper, we attempt to achieve accurate hue reproduction of the spectral colors by focusing on two steps of color correction: the capture of the spectral colors and the color characterization of digital camera. Hence it determines the relationship among the spectral color wavelength, the RGB color space of the digital camera device and the CIEXYZ color space. This study also provides a basis for further studies related to the color spectral reproduction on digital devices. In this paper, methods such as wavelength calibration of the spectral colors and digital camera characterization were utilized. The spectrum was obtained through the grating spectroscopy system. A photo of a clear and reliable primary spectrum was taken by adjusting the relative parameters of the digital camera, from which the RGB values of color spectrum was extracted in 1040 equally-divided locations. Calculated using grating equation and measured by the spectrophotometer, two wavelength values were obtained from each location. The polynomial fitting method for the camera characterization was used to achieve color correction. After wavelength calibration, the maximum error between the two sets of wavelengths is 4.38nm. According to the polynomial fitting method, the average color difference of test samples is 3.76. This has satisfied the application needs of the spectral colors in digital devices such as display and transmission.

[Evaluation of crude drugs by means of colorimeter (I). Study on correlation between color and alkaloids content of coptidis rhizoma].

PubMed

Yoshimitsu, Michiyo; Qu, Xian-You; Luo, Wei-Zao; Qin, Song-Yun

2014-05-01

To examine the correlation between alkaloids content and L*, a* and b* color indices of Rhizoma Coptidis for quality control. A colorimeter was used for the measurement of reflected light from sieved powder samples using the CIE 1976 L* a* b* color system. The content of six alkaloids were determined by HPLC. The correlation between alkaloids content and color indices of Rhizoma Coptidis was analyzed. When the particle size of Rhizoma Coptidis was less than 355 microm and the colorimeter parameters were set as measurement diameter of 3 mm, observation degree of 10, and light source of F2 and F7, the measured color was significantly correlated with total alkaloids content (r = 0.793, P < 0.05). As light source of F11, the measured color was significantly correlated with berberine content (r = 0.867, P < 0.01). The correlation between the color of powdered Coptidis Rhizoma and its alkaloids contents was found in this study. Measurment of the color of Coptidis Rhizoma can be used to assess its quality.

A robust color image fusion for low light level and infrared images

NASA Astrophysics Data System (ADS)

Liu, Chao; Zhang, Xiao-hui; Hu, Qing-ping; Chen, Yong-kang

2016-09-01

The low light level and infrared color fusion technology has achieved great success in the field of night vision, the technology is designed to make the hot target of fused image pop out with intenser colors, represent the background details with a nearest color appearance to nature, and improve the ability in target discovery, detection and identification. The low light level images have great noise under low illumination, and that the existing color fusion methods are easily to be influenced by low light level channel noise. To be explicit, when the low light level image noise is very large, the quality of the fused image decreases significantly, and even targets in infrared image would be submerged by the noise. This paper proposes an adaptive color night vision technology, the noise evaluation parameters of low light level image is introduced into fusion process, which improve the robustness of the color fusion. The color fuse results are still very good in low-light situations, which shows that this method can effectively improve the quality of low light level and infrared fused image under low illumination conditions.

Choosing colors for map display icons using models of visual search.

PubMed

Shive, Joshua; Francis, Gregory

2013-04-01

We show how to choose colors for icons on maps to minimize search time using predictions of a model of visual search. The model analyzes digital images of a search target (an icon on a map) and a search display (the map containing the icon) and predicts search time as a function of target-distractor color distinctiveness and target eccentricity. We parameterized the model using data from a visual search task and performed a series of optimization tasks to test the model's ability to choose colors for icons to minimize search time across icons. Map display designs made by this procedure were tested experimentally. In a follow-up experiment, we examined the model's flexibility to assign colors in novel search situations. The model fits human performance, performs well on the optimization tasks, and can choose colors for icons on maps with novel stimuli to minimize search time without requiring additional model parameter fitting. Models of visual search can suggest color choices that produce search time reductions for display icons. Designers should consider constructing visual search models as a low-cost method of evaluating color assignments.

THE UBV(RI){sub C} COLORS OF THE SUN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramirez, I.; Michel, R.; Schuster, W. J.

2012-06-10

Photometric data in the UBV(RI){sub C} system have been acquired for 80 solar analog stars for which we have previously derived highly precise atmospheric parameters T{sub eff}, log g, and [Fe/H] using high-resolution, high signal-to-noise ratio spectra. UBV and (RI){sub C} data for 46 and 76 of these stars, respectively, are published for the first time. Combining our data with those from the literature, colors in the UBV(RI){sub C} system, with {approx_equal} 0.01 mag precision, are now available for 112 solar analogs. Multiple linear regression is used to derive the solar colors from these photometric data and the spectroscopically derivedmore » T{sub eff}, log g, and [Fe/H] values. To minimize the impact of systematic errors in the model-dependent atmospheric parameters, we use only the data for the 10 stars that most closely resemble our Sun, i.e., the solar twins, and derive the following solar colors: (B - V){sub Sun} = 0.653 {+-} 0.005, (U - B){sub Sun} = 0.166 {+-} 0.022, (V - R){sub Sun} = 0.352 {+-} 0.007, and (V - I){sub Sun} = 0.702 {+-} 0.010. These colors are consistent, within the 1{sigma} errors, with those derived using the entire sample of 112 solar analogs. We also derive the solar colors using the relation between spectral-line-depth ratios and observed stellar colors, i.e., with a completely model-independent approach, and without restricting the analysis to solar twins. We find (B - V){sub Sun} = 0.653 {+-} 0.003, (U - B){sub Sun} = 0.158 {+-} 0.009, (V - R){sub Sun} = 0.356 {+-} 0.003, and (V - I){sub Sun} = 0.701 {+-} 0.003, in excellent agreement with the model-dependent analysis.« less

Diagnostic performance and color overlay pattern in shear wave elastography (SWE) for palpable breast mass.

PubMed

Park, Jiyoon; Woo, Ok Hee; Shin, Hye Seon; Cho, Kyu Ran; Seo, Bo Kyoung; Kang, Eun Young

2015-10-01

The purpose of this study is to evaluate the diagnostic performance of SWE in palpable breast mass and to compare with color overlay pattern in SWE with conventional US and quantitative SWE for assessing palpable breast mass. SWE and conventional breast US were performed in 133 women with 156 palpable breast lesions (81 benign, 75 malignant) between August 2013 to June 2014. Either pathology or periodic imaging surveillance more than 2 years was a reference standard. Existence of previous image was blinded to performing radiologists. US BI-RADS final assessment, qualitative and quantitative SWE measurements were evaluated. Diagnostic performances of grayscale US, SWE and US combined to SWE were calculated and compared. Correlation between pattern classification and quantitative SWE was evaluated. Both color overlay pattern and quantitative SWE improved the specificity of conventional US, from 81.48% to 96.30% (p=0.0005), without improvement in sensitivity. Color overlay pattern was significantly related to all quantitative SWE parameters and malignancy rate (p<0.0001.). The optimal cutoff of color overlay pattern was between 2 and 3. Emax with optimal cutoff at 45.1 kPa showed the highest Az value, sensitivity, specificity and accuracy among other quantitative SWE parameters (p<0.0001). Echogenic halo on grayscale US showed significant correlation with color overlay pattern and pathology (p<0.0001). In evaluation of palpable breast mass, conventional US combine to SWE improves specificity and reduces the number of biopsies that ultimately yield a benign result. Color overlay pattern classification is more quick and easy and may represent quantitative SWE measurements with similar diagnostic performances. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Reconstruction of color biomedical images by means of quaternion generic Jacobi-Fourier moments in the framework of polar pixels

PubMed Central

Camacho-Bello, César; Padilla-Vivanco, Alfonso; Toxqui-Quitl, Carina; Báez-Rojas, José Javier

2016-01-01

Abstract. A detailed analysis of the quaternion generic Jacobi-Fourier moments (QGJFMs) for color image description is presented. In order to reach numerical stability, a recursive approach is used during the computation of the generic Jacobi radial polynomials. Moreover, a search criterion is performed to establish the best values for the parameters α and β of the radial Jacobi polynomial families. Additionally, a polar pixel approach is taken into account to increase the numerical accuracy in the calculation of the QGJFMs. To prove the mathematical theory, some color images from optical microscopy and human retina are used. Experiments and results about color image reconstruction are presented. PMID:27014716

Physics-based approach to color image enhancement in poor visibility conditions.

PubMed

Tan, K K; Oakley, J P

2001-10-01

Degradation of images by the atmosphere is a familiar problem. For example, when terrain is imaged from a forward-looking airborne camera, the atmosphere degradation causes a loss in both contrast and color information. Enhancement of such images is a difficult task because of the complexity in restoring both the luminance and the chrominance while maintaining good color fidelity. One particular problem is the fact that the level of contrast loss depends strongly on wavelength. A novel method is presented for the enhancement of color images. This method is based on the underlying physics of the degradation process, and the parameters required for enhancement are estimated from the image itself.

Color-magnitude relations in nearby galaxy clusters

NASA Astrophysics Data System (ADS)

Rasheed, Mariwan A.; Mohammad, Khalid K.

2018-06-01

The rest-frame (g-r) /Mr color-magnitude relations of 12 Abell-type clusters are analyzed in the redshift range (0.02≲ z ≲ 0.10) and within a projected radius of 0.75 Mpc using photometric data from SDSS-DR9. We show that the color-magnitude relation parameters (slope, zero-point, and scatter) do not exhibit significant evolution within this low-redshift range. Thus, we can say that during the look-back time of z ˜ 0.1 all red sequence galaxies evolve passively, without any star formation activity.

A novel false color mapping model-based fusion method of visual and infrared images

NASA Astrophysics Data System (ADS)

Qi, Bin; Kun, Gao; Tian, Yue-xin; Zhu, Zhen-yu

2013-12-01

A fast and efficient image fusion method is presented to generate near-natural colors from panchromatic visual and thermal imaging sensors. Firstly, a set of daytime color reference images are analyzed and the false color mapping principle is proposed according to human's visual and emotional habits. That is, object colors should remain invariant after color mapping operations, differences between infrared and visual images should be enhanced and the background color should be consistent with the main scene content. Then a novel nonlinear color mapping model is given by introducing the geometric average value of the input visual and infrared image gray and the weighted average algorithm. To determine the control parameters in the mapping model, the boundary conditions are listed according to the mapping principle above. Fusion experiments show that the new fusion method can achieve the near-natural appearance of the fused image, and has the features of enhancing color contrasts and highlighting the infrared brilliant objects when comparing with the traditional TNO algorithm. Moreover, it owns the low complexity and is easy to realize real-time processing. So it is quite suitable for the nighttime imaging apparatus.

A CATALOG OF BULGE+DISK DECOMPOSITIONS AND UPDATED PHOTOMETRY FOR 1.12 MILLION GALAXIES IN THE SLOAN DIGITAL SKY SURVEY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simard, Luc; McConnachie, Alan W.; Trevor Mendel, J.

We perform two-dimensional, point-spread-function-convolved, bulge+disk decompositions in the g and r bandpasses on a sample of 1,123,718 galaxies from the Legacy area of the Sloan Digital Sky Survey Data Release Seven. Four different decomposition procedures are investigated which make improvements to sky background determinations and object deblending over the standard SDSS procedures that lead to more robust structural parameters and integrated galaxy magnitudes and colors, especially in crowded environments. We use a set of science-based quality assurance metrics, namely, the disk luminosity-size relation, the galaxy color-magnitude diagram, and the galaxy central (fiber) colors to show the robustness of our structuralmore » parameters. The best procedure utilizes simultaneous, two-bandpass decompositions. Bulge and disk photometric errors remain below 0.1 mag down to bulge and disk magnitudes of g {approx_equal} 19 and r {approx_equal} 18.5. We also use and compare three different galaxy fitting models: a pure Sersic model, an n{sub b} = 4 bulge + disk model, and a Sersic (free n{sub b}) bulge + disk model. The most appropriate model for a given galaxy is determined by the F-test probability. All three catalogs of measured structural parameters, rest-frame magnitudes, and colors are publicly released here. These catalogs should provide an extensive comparison set for a wide range of observational and theoretical studies of galaxies.« less

VizieR Online Data Catalog: OGLE UBVI phot. in Baade's Window (Paczynski+, 1999)

NASA Astrophysics Data System (ADS)

Paczynski, B.; Udalski, A.; Szymanski, M.; Kubiak, M.; Pietrzynski, G.; Soszynski, I.; Wozniak, P.; Zebrun, K.

2000-01-01

We present UBVI photometry for 8530 stars in Baade's Window obtained during the OGLE-II microlensing survey. Among these are over one thousand red clump giants. 1391 of them have photometry with errors smaller than 0.04, 0.06, 0.12, and 0.20 mag in the I, V, B, and U-band, respectively. We constructed a map of interstellar reddening. The corrected colors of the red clump giants: (U-B)0, (B-V)0, and (V-I)0 are very well correlated, indicating that a single parameter determines the observed spread of their values, reaching almost 2mag in the (U-B)0. It seems most likely that heavy element content is the dominant parameter, but it is possible that another parameter: the age (or mass) of a star moves it along the same trajectory in the color-color diagram as the metallicity. The current ambiguity can be resolved with spectral analysis, and our catalog may be useful as a finding list of red clump giants. We point out that these K giants are more suitable for a fair determination of the distribution of metallicity than brighter M giants. We also present a compilation of UBVI data for 308 red clump giants near the Sun, for which Hipparcos parallaxes are more accurate than 10%. Spectral analysis of their metallicity may provide information about the local metallicity distribution as well as the extent to which mass (age) of these stars affects their colors. (3 data files).

Postponed bifurcations of a ring-laser model with a swept parameter and additive colored noise

NASA Astrophysics Data System (ADS)

Mannella, R.; Moss, Frank; McClintock, P. V. E.

1987-03-01

The paper presents measurements of the time evolution of the statistical densities of both amplitude and field intensity obtained from a colored-noise-driven electronic circuit model of a ring laser, as the bifurcation parameter is swept through its critical values. The time-dependent second moments (intensities) were obtained from the densities. In addition, the individual stochastic trajectories were available from which the distribution of bifurcation times was constructed. For short-correlation-time (quasiwhite) noise the present results are in quantitative agreement with the recent calculations of Bogi, Colombo, Lugiato, and Mandel (1986). New results for long noise correlation times are obtained.

Objective research on tongue manifestation of patients with eczema.

PubMed

Yu, Zhifeng; Zhang, Haifang; Fu, Linjie; Lu, Xiaozuo

2017-07-20

Tongue observation often depends on subjective judgment, it is necessary to establish an objective and quantifiable standard for tongue observation. To discuss the features of tongue manifestation of patients who suffered from eczema with different types and to reveal the clinical significance of the tongue images. Two hundred patients with eczema were recruited and divided into three groups according to the diagnostic criteria. Acute group had 47 patients, subacute group had 82 patients, and chronic group had 71 patients. The computerized tongue image digital analysis device was used to detect tongue parameters. The L*a*b* color model was applied to classify tongue parameters quantitatively. For parameters such as tongue color, tongue shape, color of tongue coating, and thickness or thinness of tongue coating, there was a significant difference among acute group, subacute group and chronic group (P< 0.05). For Lab values of both tongue and tongue coating, there was statistical significance among the above types of eczema (P< 0.05). Tongue images can reflect some features of eczema, and different types of eczema may be related to the changes of tongue images. The computerized tongue image digital analysis device can reflect the tongue characteristics of patients with eczema objectively.

Removal of pollutants with determination of power consumption from landfill leachate wastewater using an electrocoagulation process: optimization using response surface methodology (RSM)

NASA Astrophysics Data System (ADS)

Asaithambi, Perumal; Beyene, Dejene; Aziz, Abdul Raman Abdul; Alemayehu, Esayas

2018-05-01

Treatment of landfill leachate wastewater by electrocoagulation process using an aluminium electrode was investigated in a batch electrochemical cell reactor. Response surface methodology based on central composite design was used to optimize the operating parameters for the removal of % color and % total organic carbon (TOC) together with power consumption from landfill leachate. Effects of three important independent parameters such as current density ( X 1), inter-electrode distance ( X 2) and solution pH ( X 3) of the landfill leachate sample on the % color and % TOC removal with power consumption were investigated. A quadratic model was used to predict the % color and % TOC removal with power consumption in different experimental conditions. The significance of each independent variable was calculated by analysis of variance. In order to achieve the maximum % color and % TOC removal with minimum of power consumption, the optimum conditions were about current density ( X 1)—5.25 A/dm2, inter-electrode distance ( X 2)—1 cm and initial solution of effluent pH ( X 3)—7.83, with the yield of color removal of 74.57%, and TOC removal of 51.75% with the power consumption of 14.80 kWh/m3. Electrocoagulation process could be applied to remove pollutants from industrial effluents and wastewater.

An iPhone application using a novel stool color detection algorithm for biliary atresia screening.

PubMed

Hoshino, Eri; Hayashi, Kuniyoshi; Suzuki, Mitsuyoshi; Obatake, Masayuki; Urayama, Kevin Y; Nakano, Satoshi; Taura, Yasuyuki; Nio, Masaki; Takahashi, Osamu

2017-10-01

The stool color card has been the primary tool for identifying acholic stools in infants with biliary atresia (BA), in several countries. However, BA stools are not always acholic, as obliteration of the bile duct occurs gradually. This study aims to introduce Baby Poop (Baby unchi in Japanese), a free iPhone application, employing a detection algorithm to capture subtle differences in colors, even with non-acholic BA stools. The application is designed for use by caregivers of infants aged approximately 2 weeks-1 month. Baseline analysis to determine optimal color parameters predicting BA stools was performed using logistic regression (n = 50). Pattern recognition and machine learning processes were performed using 30 BA and 34 non-BA images. Additional 5 BA and 35 non-BA pictures were used to test accuracy. Hue, saturation, and value (HSV) were the preferred parameter for BA stool identification. A sensitivity and specificity were 100% (95% confidence interval 0.48-1.00 and 0.90-1.00, respectively) even among a collection of visually non-acholic, i.e., pigmented BA stools and relatively pale-colored non-BA stools. Results suggest that an iPhone mobile application integrated with a detection algorithm is an effective and convenient modality for early detection of BA, and potentially for other related diseases.

Recognition memory for colored and black-and-white scenes in normal and color deficient observers (dichromats).

PubMed

Brédart, Serge; Cornet, Alyssa; Rakic, Jean-Marie

2014-01-01

Color deficient (dichromat) and normal observers' recognition memory for colored and black-and-white natural scenes was evaluated through several parameters: the rate of recognition, discrimination (A'), response bias (B"D), response confidence, and the proportion of conscious recollections (Remember responses) among hits. At the encoding phase, 36 images of natural scenes were each presented for 1 sec. Half of the images were shown in color and half in black-and-white. At the recognition phase, these 36 pictures were intermixed with 36 new images. The participants' task was to indicate whether an image had been presented or not at the encoding phase, to rate their level of confidence in his her/his response, and in the case of a positive response, to classify the response as a Remember, a Know or a Guess response. Results indicated that accuracy, response discrimination, response bias and confidence ratings were higher for colored than for black-and-white images; this advantage for colored images was similar in both groups of participants. Rates of Remember responses were not higher for colored images than for black-and-white ones, whatever the group. However, interestingly, Remember responses were significantly more often based on color information for colored than for black-and-white images in normal observers only, not in dichromats.

Carded Tow Real-Time Color Assessment: A Spectral Camera-Based System

PubMed Central

Furferi, Rocco; Governi, Lapo; Volpe, Yary; Carfagni, Monica

2016-01-01

One of the most important parameters to be controlled during the production of textile yarns obtained by mixing pre-colored fibers, is the color correspondence between the manufactured yarn and a given reference, usually provided by a designer or a customer. Obtaining yarns from raw pre-colored fibers is a complex manufacturing process entailing a number of steps such as laboratory sampling, color recipe corrections, blowing, carding and spinning. Carding process is the one devoted to transform a “fuzzy mass” of tufted fibers into a regular mass of untwisted fibers, named “tow”. During this process, unfortunately, the correspondence between the color of the tow and the target one cannot be assured, thus leading to yarns whose color differs from the one used for reference. To solve this issue, the main aim of this work is to provide a system able to perform a spectral camera-based real-time measurement of a carded tow, to assess its color correspondence with a reference carded fabric and, at the same time, to monitor the overall quality of the tow during the carding process. Tested against a number of differently colored carded fabrics, the proposed system proved its effectiveness in reliably assessing color correspondence in real-time. PMID:27589765

[Preparation and chromaticity properties of colored dental 3Y-TZP ceramics].

PubMed

Yi, Yuan-fu; Wang, Chen; Tian, Jie-mo; Liu, Hong-chen; Wen, Ning

2008-10-01

To obtain and investigate the chromaticity properties of colored dental 3Y-TZP ceramics with different colorant combinations. Colorant combinations were mixed with TZ-3Y-S powder, then the mixtures were compacted at 200 MPa using cold isostatic pressure, densely sintered at 1500 degrees C for 2 h forming 5 graded colored dental zirconia ceramics. Specimen were sectioned into 10 mm x 10 mm x 0.5 mm and 10 mm x l0 mmx 1 mm slices from the sintered blocks. Color measurement was performed under black background using spectrophotometer. The chromaticity properties were compared with that of the VITA In-Ceram YZ shade guide. Five colored dental zirconia ceramics were obtained. The lightness decreased gradually, and the chroma value increased gradually. The color differences of the two thickness specimens were little. The parameters of the color space were L*: 67.76-77.78; a*: -2.19-3.80; b*: 12.13-25.01, which was similar with that of the VITA In-Ceram YZ shade guide, while the lowest value of lightness was relatively higher than that of the VITA In-Ceram YZ shade guide. Colored 3Y-TZP dental ceramics are suitable for clinical use. There is a need to develop more darkness shaded zirconia dental ceramics.

Characterization of Defects in Lumber Using Color, Shape, and Density Information

Treesearch

B.H. Bond; D. Earl Kline; Philip A. Araman

1998-01-01

To help guide the development of multi-sensor machine vision systems for defect detection in lumber, a fundamental understanding of wood defects is needed. The purpose of this research was to advance the basic understanding of defects in lumber by describing them in terms of parameters that can be derived from color and x-ray scanning technologies and to demonstrate...

Segmentation and classification of dermatological lesions

NASA Astrophysics Data System (ADS)

Sáez, Aurora; Acha, Begoña; Serrano, Carmen

2010-03-01

Certain skin diseases are chronic, inflammatory and without cure. However, there are many treatment options that can clear them for a period of time. Measuring their severity and assessing their extent, is a fundamental issue to determine the efficacy of the treatment under test. Two of the most important parameters of severity assessment are Erythema (redness) and Scaliness. Physicians classify these parameters into several grades by visual grading method. In this paper a color image segmentation and classification algorithm is developed to obtain an assessment of erythema and scaliness of dermatological lesions. Color digital photographs taken under an acquisition protocol form the database. Difference between green band and blue band of images in RGB color space shows two modes (healthy skin and lesion) with clear separation. Otsu's method is applied to this difference in order to isolate the lesion. After the skin disease is segmented, some color and texture features are calculated and they are the inputs to a Fuzzy-ARTMAP neural network. The neural network classifies them into the five grades of erythema and the five grades of scaliness. The method has been tested with 31 images with a success percentage of 83.87 % when the images are classified in erythema, and 77.42 % for scaliness classification.

Colour measurement of colostrum for estimation of colostral IgG and colostrum composition in dairy cows.

PubMed

Gross, Josef J; Kessler, Evelyne C; Bruckmaier, Rupert M

2014-11-01

Instruments for on-farm determination of colostrum quality such as refractometers and densimeters are increasingly used in dairy farms. The colour of colostrum is also supposed to reflect its quality. A paler or mature milk-like colour is associated with a lower colostrum value in terms of its general composition compared with a more yellowish and darker colour. The objective of this study was to investigate the relationships between colour measurement of colostrum using the CIELAB colour space (CIE L*=from white to black, a*=from red to green, b*=from yellow to blue, chroma value G=visual perceived colourfulness) and its composition. Dairy cow colostrum samples (n=117) obtained at 4·7±1·5 h after parturition were analysed for immunoglobulin G (IgG) by ELISA and for fat, protein and lactose by infrared spectroscopy. For colour measurements, a calibrated spectrophotometer was used. At a cut-off value of 50 mg IgG/ml, colour measurement had a sensitivity of 50·0%, a specificity of 49·5%, and a negative predictive value of 87·9%. Colostral IgG concentration was not correlated with the chroma value G, but with relative lightness L*. While milk fat content showed a relationship to the parameters L*, a*, b* and G from the colour measurement, milk protein content was not correlated with a*, but with L*, b*, and G. Lactose concentration in colostrum showed only a relationship with b* and G. In conclusion, parameters of the colour measurement showed clear relationships to colostral IgG, fat, protein and lactose concentration in dairy cows. Implementation of colour measuring devices in automatic milking systems and milking parlours might be a potential instrument to access colostrum quality as well as detecting abnormal milk.

Interactive model evaluation tool based on IPython notebook

NASA Astrophysics Data System (ADS)

Balemans, Sophie; Van Hoey, Stijn; Nopens, Ingmar; Seuntjes, Piet

2015-04-01

In hydrological modelling, some kind of parameter optimization is mostly performed. This can be the selection of a single best parameter set, a split in behavioural and non-behavioural parameter sets based on a selected threshold or a posterior parameter distribution derived with a formal Bayesian approach. The selection of the criterion to measure the goodness of fit (likelihood or any objective function) is an essential step in all of these methodologies and will affect the final selected parameter subset. Moreover, the discriminative power of the objective function is also dependent from the time period used. In practice, the optimization process is an iterative procedure. As such, in the course of the modelling process, an increasing amount of simulations is performed. However, the information carried by these simulation outputs is not always fully exploited. In this respect, we developed and present an interactive environment that enables the user to intuitively evaluate the model performance. The aim is to explore the parameter space graphically and to visualize the impact of the selected objective function on model behaviour. First, a set of model simulation results is loaded along with the corresponding parameter sets and a data set of the same variable as the model outcome (mostly discharge). The ranges of the loaded parameter sets define the parameter space. A selection of the two parameters visualised can be made by the user. Furthermore, an objective function and a time period of interest need to be selected. Based on this information, a two-dimensional parameter response surface is created, which actually just shows a scatter plot of the parameter combinations and assigns a color scale corresponding with the goodness of fit of each parameter combination. Finally, a slider is available to change the color mapping of the points. Actually, the slider provides a threshold to exclude non behaviour parameter sets and the color scale is only attributed to the remaining parameter sets. As such, by interactively changing the settings and interpreting the graph, the user gains insight in the model structural behaviour. Moreover, a more deliberate choice of objective function and periods of high information content can be identified. The environment is written in an IPython notebook and uses the available interactive functions provided by the IPython community. As such, the power of the IPython notebook as a development environment for scientific computing is illustrated (Shen, 2014).

The effect of different shades of specific luting agents and IPS empress ceramic thickness on overall color.

PubMed

Terzioğlu, Hakan; Yilmaz, Burak; Yurdukoru, Bengul

2009-10-01

The color stability of both porcelain and luting materials is very important for the esthetics of laminate veneers and all-ceramic crowns. The purpose of this study was to determine the effect of different shades of resin-based luting cement and the thickness of IPS Empress ceramics on the final color of the restorations. Resin-based dual-polymerized composite cement in two different shades (RelyX ARC) and ceramic disks of different thicknesses were selected for the study. Forty specimens (ten each of four different thicknesses: 0.5 mm, 1 mm, 2 mm, and 3 mm) were used for the evaluation. Initial specimen color parameters were determined in a Commission Internationale de l'Eclairage L*a*b* color order system with a colorimeter. Two different shades of the cement were prepared as polymerized layers and applied to one face of the specimens in order. Color changes were calculated between baseline color measurements and measurements after cementation. Color difference data were analyzed statistically. All specimens showed a significant color shift (DE > 3.7) after cementation regardless of the cement shade. However, the differences in the cement shade did not significantly affect the final color of the ceramic specimens for any thickness, and color shifts were not perceivable between the different shades of cement. (Int J Periodontics Restorative Dent 2009;29:499-505.).

Display Parameters and Requirements

NASA Astrophysics Data System (ADS)

Bahadur, Birendra

The following sections are included: * INTRODUCTION * HUMAN FACTORS * Anthropometry * Sensory * Cognitive * Discussions * THE HUMAN VISUAL SYSTEM - CAPABILITIES AND LIMITATIONS * Cornea * Pupil and Iris * Lens * Vitreous Humor * Retina * RODS - NIGHT VISION * CONES - DAY VISION * RODS AND CONES - TWILIGHT VISION * VISUAL PIGMENTS * MACULA * BLOOD * CHOROID COAT * Visual Signal Processing * Pathways to the Brain * Spatial Vision * Temporal Vision * Colour Vision * Colour Blindness * DICHROMATISM * Protanopia * Deuteranopia * Tritanopia * ANOMALOUS TRICHROMATISM * Protanomaly * Deuteranomaly * Tritanomaly * CONE MONOCHROMATISM * ROD MONOCHROMATISM * Using Colour Effectively * COLOUR MIXTURES AND THE CHROMATICITY DIAGRAM * Colour Matching Functions and Chromaticity Co-ordinates * CIE 1931 Colour Space * CIE PRIMARIES * CIE COLOUR MATCHING FUNCTIONS AND CHROMATICITY CO-ORDINATES * METHODS FOR DETERMINING TRISTIMULUS VALUES AND COLOUR CO-ORDINATES * Spectral Power Distribution Method * Filter Method * CIE 1931 CHROMATICITY DIAGRAM * ADDITIVE COLOUR MIXTURE * CIE 1976 Chromaticity Diagram * CIE Uniform Colour Spaces and Colour Difference Formulae * CIELUV OR L*u*v* * CIELAB OR L*a*b* * CIE COLOUR DIFFERENCE FORMULAE * Colour Temperature and CIE Standard Illuminants and source * RADIOMETRIC AND PHOTOMETRIC QUANTITIES * Photopic (Vλ and Scotopic (Vλ') Luminous Efficiency Function * Photometric and Radiometric Flux * Luminous and Radiant Intensities * Incidence: Illuminance and Irradiance * Exitance or Emittance (M) * Luminance and Radiance * ERGONOMIC REQUIREMENTS OF DISPLAYS * ELECTRO-OPTICAL PARAMETERS AND REQUIREMENTS * Contrast and Contrast Ratio * Luminance and Brightness * Colour Contrast and Chromaticity * Glare * Other Aspects of Legibility * SHAPE AND SIZE OF CHARACTERS * DEFECTS AND BLEMISHES * FLICKER AND DISTORTION * ANGLE OF VIEW * Switching Speed * Threshold and Threshold Characteristic * Measurement Techniques For Electro-optical Parameters * RADIOMETRIC MEASUREMENTS * Broadband Radiometry or Filtered Photodetector Radiometric Method * Spectroradiometric Method * PHOTOMETRIC MEASUREMENTS * COLOUR MEASUREMENTS * LUMINANCE, CONTRAST RATIO, THRESHOLD CHARACTERISTIC AND POLAR PLOT * SWITCHING SPEED * ELECTRICAL AND LIFE PARAMETERS AND REQUIREMENTS * Operating Voltage, Current Drainage and Power Consumption * Operating Frequency * Life Expectancy * LCD FAILURE MODES * Liquid Crystal Materials * Substrate Glass * Electrode Patterns * Alignment and Aligning Material * Peripheral and End Plug Seal * Spacers * Crossover Material * Polarizers and Reflectors * Connectors * Heater * Colour Filters * Backlighting System * Explanation For Some of the Observed Defects * BLOOMING PIXELS * POLARIZER RELATED DEFECTS * DIFFERENTIAL THERMAL EXPANSION RELATED DEFECTS * ELECTROCHEMICAL AND ELECTROHYDRODYNAMIC RELATED DEFECTS * REVERSE TWIST AND REVERSE TILT * MEMORY OR REMINISCENT CONTRAST * LCD RELIABILRY AND ACCELERATED LIFE TESTING * ACKNOWLEDGEMENTS * REFERENCES * APPENDIX

Electrochemical fabrication and optical properties of porous tin oxide films with structural colors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Hua; Shu, Shiwei; Lee, Chris

2014-10-21

Photonic crystals with porous features not only provide the capability to control light but also enable structural colors that are environmentally sensitive. Here, we report a novel kind of tin oxide-based photonic crystal featuring periodically arranged air pores fabricated by the periodic anodization of tin foil. The existence of a photonic band gap in the fabricated structure is verified by its vivid color, and its reflective spectra which are responsive to environmental stimuli. Furthermore, the sample colors (i.e., the photonic band gap positions) can be easily adjusted by manipulating the anodization parameters. The theoretical modeling results of these tin oxidemore » photonic crystals agree well with the reported experimental ones.« less

Microbial pigments as natural color sources: current trends and future perspectives.

PubMed

Tuli, Hardeep S; Chaudhary, Prachi; Beniwal, Vikas; Sharma, Anil K

2015-08-01

Synthetic colors have been widely used in various industries including food, textile, cosmetic and pharmaceuticals. However toxicity problems caused by synthetic pigments have triggered intense research in natural colors and dyes. Among the natural Sources, pigment producing microorganisms hold a promising potential to meet present day challenges. Furthermore natural colors not only improve the marketability of the product but also add extra features like anti oxidant, anti cancer properties etc. In this review, we present various sources of microbial pigments and to explore their biological and clinical properties like antimicrobial, antioxidant, anticancer and anti inflammatory. The study also emphasizes upon key parameters to improve the bioactivity and production of microbial pigments for their commercial use in pharmacological and medical fields.

Controlling the digital transfer process

NASA Astrophysics Data System (ADS)

Brunner, Felix

1997-02-01

The accuracy of today's color management systems fails to satisfy the requirements of the graphic arts market. A first explanation for this is that color calibration charts on which these systems rely, because of print technical reasons, are subject to color deviations and inconsistencies. A second reason is that colorimetry describes the human visual perception of color differences and has no direct relation to the rendering technology itself of a proofing or printing device. The author explains that only firm process control of the many parameters in offset printing by means of a system as for example EUROSTANDARD System Brunner, can lead to accurate and consistent calibration of scanner, display, proof and print. The same principles hold for the quality management of digital presses.

Bioinspired Non-iridescent Structural Color from Polymer Blend Thin Films

NASA Astrophysics Data System (ADS)

Nallapaneni, Asritha; Shawkey, Matthew; Karim, Alamgir

Colors exhibited in biological species are either due to natural pigments, sub-micron structural variation or both. Structural colors thus exhibited can be iridescent (ID) or non-iridescent (NID) in nature. NID colors originate due to interference and coherent scattering of light with quasi-ordered micro- and nano- structures. Specifically, in Eastern Bluebird (Sialia sialis) these nanostructures develop as a result of phase separation of β-keratin from cytoplasm present in cells. We replicate these structures via spinodal blend phase separation of PS-PMMA thin films. Colors of films vary from ultraviolet to blue. Scattering of UV-visible light from selectively leeched phase separated blends are studied in terms of varying domain spacing (200nm to 2 μm) of film. We control these parameters by tuning annealing time and temperature. Angle-resolved spectroscopy studies suggest that the films are weakly iridescent and scattering from phase-separated films is more diffused when compared to well-mixed films. This study offers solutions to several color-based application in paints and coatings industry.

Escher in color space: individual-differences multidimensional scaling of color dissimilarities collected with a gestalt formation task.

PubMed

Bimler, David; Kirkland, John; Pichler, Shaun

2004-02-01

The structure of color perception can be examined by collecting judgments about color dissimilarities. In the procedure used here, stimuli are presented three at a time on a computer monitor and the spontaneous grouping of most-similar stimuli into gestalts provides the dissimilarity comparisons. Analysis with multidimensional scaling allows such judgments to be pooled from a number of observers without obscuring the variations among them. The anomalous perceptions of color-deficient observers produce comparisons that are represented well by a geometric model of compressed individual color spaces, with different forms of deficiency distinguished by different directions of compression. The geometrical model is also capable of accommodating the normal spectrum of variation, so that there is greater variation in compression parameters between tests on normal subjects than in those between repeated tests on individual subjects. The method is sufficiently sensitive and the variations sufficiently large that they are not obscured by the use of a range of monitors, even under somewhat loosely controlled conditions.

Objective measurement of erythema in psoriasis using digital color photography with color calibration.

PubMed

Raina, A; Hennessy, R; Rains, M; Allred, J; Hirshburg, J M; Diven, D G; Markey, M K

2016-08-01

Traditional metrics for evaluating the severity of psoriasis are subjective, which complicates efforts to measure effective treatments in clinical trials. We collected images of psoriasis plaques and calibrated the coloration of the images according to an included color card. Features were extracted from the images and used to train a linear discriminant analysis classifier with cross-validation to automatically classify the degree of erythema. The results were tested against numerical scores obtained by a panel of dermatologists using a standard rating system. Quantitative measures of erythema based on the digital color images showed good agreement with subjective assessment of erythema severity (κ = 0.4203). The color calibration process improved the agreement from κ = 0.2364 to κ = 0.4203. We propose a method for the objective measurement of the psoriasis severity parameter of erythema and show that the calibration process improved the results. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Correlation of lycopene measured by HPLC with the L, a, b color readings of a hydroponic tomato and the relationship of maturity with color and lycopene content

NASA Technical Reports Server (NTRS)

Arias, R.; Lee, T. C.; Logendra, L.; Janes, H.

2000-01-01

Tomatoes (Lycopersicon esculentum cv. Laura) were separated, according to the ripening stage, by a sensory panel into seven groups, and color was measured on the tomato surface with a Minolta Chroma meter. The L, a, b, hue, chroma, and lycopene content were plotted against the maturity stages of the tomatoes, and several good correlations were found. The a/b ratio and the lycopene content were the parameters that allowed six of seven maturity groups in the tomato to be statistically distinguished. The lycopene content, measured by HPLC, was also correlated with the color measurements, and the a, a/b, and (a/b)(2) color factors produced the best regressions. An estimation of the lycopene content in tomatoes can be achieved by using a portable chroma meter, with a possible field usage application. Equations to calculate the lycopene content of tomatoes based on the color readings are reported.

Effect of Children's Drinks on Color Stability of Different Dental Composites: An in vitro Study.

PubMed

Habib, Ahmed Nour El-Din Ahmed; Abdelmoniem, Soad Abdelmoniem; Mahmoud, Sara Ahmed

To assess the effect of four different children's drinks on color stability of resin dental composites. A total of one hundred and twenty specimens were prepared from Grandio SO, Filtek Z350 XT and Filtek Z250 XT (forty specimens each). Specimens were thermocycled, then each group was further subdivided into four subgroups (n=10) according to the immersion media which were chocolate milk, mango juice, orange fizzy drink, and water (control). The initial color parameters of each specimen were recorded before immersion (baseline) and color change values were recorded three and seven days after immersion in each solution using a digital spectrophotometer. Atomic force microscope was used to measure the surface roughness in randomly selected samples after one week immersion in children's drinks. All the children's drinks produced color changes in the examined resin dental composites, yet there was no statistical significant difference between the effects of tested drinks on the color changes (mean ΔE) of the three different dental composites (P>0.05). All tested children's drinks caused clinically unacceptable color changes of the tested resin dental composites. Immersion in chocolate milk and orange fizzy led to the highest color changes in the tested resin dental composites.

Analysis of the Color and Fluorescence Alterations of Enamel and Dentin Treated With Hydrogen Peroxide.

PubMed

Caneppele, Taciana Marco Ferraz; Rocha Gomes Torres, Carlos; Bresciani, Eduardo

2015-10-01

The aim of this study was to evaluate the effect of hydrogen peroxide whitening on fluorescence and color of bovine enamel and dentin. Twenty five dentin discs and 25 enamel discs, with 6 mm diameter and 1 mm thick, were obtained. Direct fluorescence (spectrofluorophotometry) and color (spectrophotometry) were assessed. After fluorescence and color baseline measurements, specimens were immersed in a 35% hydrogen peroxide (HP) solution for 1 h. This procedure was repeated after 7 days. Final fluorescence and color measurements were performed after the second immersion. Chemical characterization of 5 additional specimens was also performed. Data were submitted to repeated analysis of variance and Tukey's test for fluorescence and unpaired t-test for color and chemical components (p<0.05). Fluorescence decreased significantly in dentin specimens after whitening. Enamel presented lower fluorescence than dentin at baseline, but this parameter did not decrease after whitening. Color changes were observed for both substrates, with significantly greater whitening effect in dentin (ΔE=10.37) (p<0.001). Whitening by hydrogen peroxide induced significant decrease in fluorescence of tooth dentin and promoted significant color changes in dentin and enamel with more accentuated outcomes in dentin.

[The effect of methyl-containing supplements during pregnancy on the phenotypic modification of offspring hair color in rats].

PubMed

Prasolova, L A; Trut, L N; Os'kina, I N; Gulevich, R G; Pliusnina, I Z; Vsevolodov, E B; Latypov, I F

2006-01-01

The effect of methyl supplements to the diet of pregnant homozygous (AAHH) female rats with agouti coat color mated with homozygous (aahh) males on the phenotypic modification of the coat color of their heterozygous offspring (AaHh) has been studied. Comparative morphological analysis of the main parameters of hair that determine coat color, including the total length of hairs of different types and the length of the upper black (eumelanin) and light (pheomelanin) parts of awn hairs has been performed. The pattern of pigment granule distribution among hair layers has been analyzed. The melanin content of the hair has been determined using electron spin resonance (ESR). Although all offspring have a typical agouti coat color (alternating black and light portions of hair), 39% of them have a darker coat color than control and other experimental rats have. The main differences between the offspring with darkened and standard coat colors are accounted for by the ratio between the eumelanin and pheomelanin portions of awn hairs. In darkened offspring, this ratio is significantly higher than in control rats. The possible mechanisms of the phenotypic modification of agouti coat color in experimental animals are discussed.

Tongue's substance and coating recognition analysis using HSV color threshold in tongue diagnosis

NASA Astrophysics Data System (ADS)

Kamarudin, Nur Diyana; Ooi, Chia Yee; Kawanabe, Tadaaki; Mi, Xiaoyu

2016-07-01

In ISO TC249 conference, tongue diagnosis has been one of the most active research and their objectifications has become significant with the help of numerous statistical and machine learning algorithm. Color information of substance or tongue body has kept valuable information regarding the state of disease and its correlation with the internal organs. In order to produce high reproducibility of color measurement analysis, tongue images have to undergo several procedures such as color correction, segmentation and tongue's substance-coating separation. This paper presents a novel method to recognize substance and coating from tongue images and eliminate the tongue coating for accurate substance color measurement for diagnosis. By utilizing Hue, Saturation, Value (HSV) color space, new color-brightness threshold parameters have been devised to improve the efficiency of tongue's substance and coating separation procedures and eliminate shadows. The algorithm offers fast processing time around 0.98 seconds for 60,000 pixels tongue image. The successful tongue's substance and coating separation rate reported is 90% compared to the labelled data verified by the practitioners. Using 300 tongue images, the substance Lab color measurement with small standard deviation had revealed the effectiveness of this proposed method in computerized tongue diagnosis system.

Grapevine-shoot stilbene extract as a preservative in red wine.

PubMed

Raposo, Rafaela; Ruiz-Moreno, María José; Garde-Cerdán, Teresa; Puertas, Belén; Moreno-Rojas, José Manuel; Gonzalo-Diago, Ana; Guerrero, Raúl; Ortíz, Víctor; Cantos-Villar, Emma

2016-04-15

This paper reports the use of a grapevine-shoot stilbene extract (Vineatrol®) as a preservative in red wine. Its effectiveness to preserve red wine quality under two different winemaking systems (traditional and Ganimede) was studied at bottling and after twelve months of storage in bottle. Enological parameters, color related parameters, volatile composition, sensory analysis and olfactometric profile were evaluated. At bottling wines treated with Vineatrol showed higher color related parameters and higher score in sensory analysis than those treated with SO2. The use of SO2 increased ester and alcohol volatile compounds in relation to the use of Vineatrol. Wine olfactometric profile was modified by Vineatrol addition. Two new odorant zones with high modified frequency appeared in wines treated with Vineatrol. After 12months of storage in bottle, wines treated with Vineatrol showed parameters related to oxidation. The weak point of the process seemed to be the evolution during the storage in bottle. Copyright © 2015 Elsevier Ltd. All rights reserved.

Physical and chemical properties of Nam Prig Noom, a Thai green-chili paste, following ultra-high pressure and thermal processes

NASA Astrophysics Data System (ADS)

Apichartsrangkoon, Arunee; Srisajjalertwaja, Siriwan; Chaikham, Pittaya; Hirun, Sathira

2013-03-01

A study of processing green-chili pastes (Nam Prig Noom) by pressurization (100-600 MPa/30-50°C/20 min), pasteurization (90°C/3-5 min) or sterilization (121°C/4 min), subsequently, their physical, biochemical and microbiological qualities as well as the sensory acceptance were assessed. It was found that pressure at low levels (100-300 MPa) could improve activities of enzyme peroxidase (POD), polyphenoloxidase (PPO) and lypoxygenase (LOX) in the chili paste by more than 100%, while pressures above 500 or 300 MPa combined with heat would significantly inactivate these enzyme activities. Both color parameters and enzyme activities illustrated that though some enzymatic browning occurred with the pressurized products indicated by b* (yellowish) parameter, the magnitude of these browning was still milder than those thermally treated products indicated by-a* (greenness) and L (lightness) parameters, presumably as a consequence of the Maillard reaction. Moreover, the sensory scores were found in accordance with color parameters, firmness and capsaicin contents.

The spectral energy distribution of galaxies at z > 2.5: Implication from the Herschel/SPIRE color-color diagram

NASA Astrophysics Data System (ADS)

Yuan, Fangting; Buat, Veronique; Burgarella, Denis; Ciesla, Laure; Heinis, Sebastien; Shen, Shiyin; Shao, Zhengyi; Hou, Jinliang

2015-08-01

We use the Herschel SPIRE color-color diagram to study the spectral energy distribution (SED) and the redshift estimation of high-z galaxies. We collect a sample of 57 galaxies with spectroscopically confirmed redshifts and reliable flux measurements at redshift z=2.5-6.4, and compare their average SPIRE colors with SED templates from local and high-z libraries. We find that local SEDs are inconsistent with high-z observations. For the libraries of Chary & Elbaz (2001) and Dale & Helou (2002), the local calibrations of the parameters LIR and alpha need to be adjusted to around 1011Lsun and 1.5 to describe the average colors given by the observations. For high-z libraries, the templates of Magdis et al. (2012) can well describe the average colors of the observations at high redshift, justifying their assumption of an evolution of SED from z=0 to 3. Using the templates of Magdis et al. (2012), we defined color cuts to divide the SPIRE color-color diagram into different regions with different mean redshifts. We tested this method and two other color cut methods 500 micron risers and the method of Amblard et al. (2010) using a large sample of 786 Herschel-selected galaxies, and find that these color cut methods can separate the sample into populations with different mean redshifts, although the dispersion of redshifts in each population is quite large.

Performance assessment of Vita Easy Shade spectrophotometer on colour measurement of aesthetic dental materials.

PubMed

AlGhazali, N; Burnside, G; Smith, R W; Preston, A J; Jarad, F D

2011-12-01

Four different shades were used to produce 20 samples of resin-based composite and 20 samples of porcelain to evaluate the performance ability of an intra oral test spectrophotometer compared to a reference spectrophotometer. The absolute colour coordinates CIELAB values measured with both spectrophotometers were significantly different (p < 0.001). However, a high correlation was found (p < 0.001) despite the low concordance noticed. The colour difference deltaE* values calculated between different shades also were significantly different between both spectrophotometers (p < 0.05). Therefore, the Easy Shade can be used in dental practice and dental research with some limitations.

A feedback control strategy for the airfoil system under non-Gaussian colored noise excitation.

PubMed

Huang, Yong; Tao, Gang

2014-09-01

The stability of a binary airfoil with feedback control under stochastic disturbances, a non-Gaussian colored noise, is studied in this paper. First, based on some approximated theories and methods the non-Gaussian colored noise is simplified to an Ornstein-Uhlenbeck process. Furthermore, via the stochastic averaging method and the logarithmic polar transformation, one dimensional diffusion process can be obtained. At last by applying the boundary conditions, the largest Lyapunov exponent which can determine the almost-sure stability of the system and the effective region of control parameters is calculated.

Stokes image reconstruction for two-color microgrid polarization imaging systems.

PubMed

Lemaster, Daniel A

2011-07-18

The Air Force Research Laboratory has developed a new microgrid polarization imaging system capable of simultaneously reconstructing linear Stokes parameter images in two colors on a single focal plane array. In this paper, an effective method for extracting Stokes images is presented for this type of camera system. It is also shown that correlations between the color bands can be exploited to significantly increase overall spatial resolution. Test data is used to show the advantages of this approach over bilinear interpolation. The bounds (in terms of available reconstruction bandwidth) on image resolution are also provided.

A feedback control strategy for the airfoil system under non-Gaussian colored noise excitation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Yong, E-mail: hy@njust.edu.cn, E-mail: taogang@njust.edu.cn; Tao, Gang, E-mail: hy@njust.edu.cn, E-mail: taogang@njust.edu.cn

2014-09-01

The stability of a binary airfoil with feedback control under stochastic disturbances, a non-Gaussian colored noise, is studied in this paper. First, based on some approximated theories and methods the non-Gaussian colored noise is simplified to an Ornstein-Uhlenbeck process. Furthermore, via the stochastic averaging method and the logarithmic polar transformation, one dimensional diffusion process can be obtained. At last by applying the boundary conditions, the largest Lyapunov exponent which can determine the almost-sure stability of the system and the effective region of control parameters is calculated.

How is the instrumental color of meat measured?

PubMed

Tapp, W N; Yancey, J W S; Apple, J K

2011-09-01

Peer-reviewed journal articles (n=1068) were used to gather instrumental color measurement information in meat science research. The majority of articles, published in 10 peer-reviewed journals, originated from European countries (44.8%) and North America (38.5%). The predominant species was pork (44.2%), and most researchers used Minolta (60.0%) over Hunter (31.6%) colorimeters. Much of the research was done using illuminant D65 (32.3%); nevertheless, almost half (48.9%) of the articles did not report the illuminant. Moreover, a majority of the articles did not report aperture size (73.6%) or the number of readings per sample (52.4%). Many factors influence meat color, and a considerable proportion of the peer-reviewed, published research articles failed to include information necessary to replicate and/or interpret instrumental color results; therefore, a standardized set of minimum reportable parameters for meat color evaluation should be identified. Copyright © 2011 Elsevier Ltd. All rights reserved.

Efficiency of malaise traps and colored pan traps for collecting flower visiting insects from three forested ecosystems

Treesearch

Joshua W. Campbell; J.L. Hanula

2007-01-01

Pan and Malaise traps have been used widely to sample insect abundance and diversity, but no studies have compared their performance for sampling pollinators in forested ecosystems. Malaise trap design and color of pan traps are important parameters that influence insect pollinator catches. We compared pan trap (blue, yellow, white, and red) and Malaise trap catches...

Changes in the color of white chocolate during storage: potential roles of lipid oxidation and non-enzymatic browning reactions.

PubMed

Rossini, Karina; Noreña, Caciano P Z; Brandelli, Adriano

2011-06-01

Three different samples of white chocolate were prepared: a sample with a synthetic antioxidant, another with casein peptides as natural antioxidant, and a third sample without any kind of antioxidant. Parameters associated with lipid oxidation and non-enzymatic browning were evaluated in the different samples of white chocolate during 10 months storage at 20 and 28°C. Acidity, thiobarbituric acid reactive substances and peroxide values increased with the incubation time. Samples stored at 20°C often showed lower values for these parameters than those stored at 28°C, although the differences were not always significant. The values for water activity increased from 0.4 to 0.53-0.57 during the period of 10 months. The color parameter a* was increased in samples stored at 28°C from month 5, and the parameter b* was lower in samples containing antioxidants from month 2. The addition of antioxidants did not significantly influence most the parameters studied, suggesting that the main parameters governing the alterations of white chocolate during its shelf-life was the storage temperature and increase in water activity.

Selection, constraint, and the evolution of coloration in African starlings.

PubMed

Maia, Rafael; Rubenstein, Dustin R; Shawkey, Matthew D

2016-05-01

Colorful plumage plays a prominent role in the evolution of birds, influencing communication (sexual/social selection), and crypsis (natural selection). Comparative studies have focused primarily on these selective pressures, but the mechanisms underlying color production can also be important by constraining the color gamut upon which selection acts. Iridescence is particularly interesting to study the interaction between selection and color-producing mechanisms because a broad range of colors can be produced with a shared template, and innovations to this template further expand this by increasing the parameters interacting to produce colors. We examine the patterns of ornamentation and dichromatism evolution in African starlings, a group remarkably diverse in color production mechanisms, social systems, and ecologies. We find that the presence of iridescence is ancestral to the group, being predominantly lost in females and cooperative breeders, as well as species with less labile templates. Color-producing mechanisms interact and are the main predictors of plumage ornamentation and elaboration, with little influence of selective pressures in their evolution. Dichromatism, however is influenced by social system and the loss of iridescence. Our results show the importance of considering both selection and constraints, and the different roles that they may have, in the evolution of ornamentation and dimorphism. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

The influence of tooth color on preparation design for laminate veneers from a minimally invasive perspective: case report.

PubMed

Coachman, Christian; Gurel, Galip; Calamita, Marcelo; Morimoto, Susana; Paolucci, Braulio; Sesma, Newton

2014-01-01

Various types of dental preparations for laminate veneers have been proposed,depending on factors such as the properties of the ceramic material, remaining dental structure color, need for altering the dental contour, laboratory fabrication technique, and occlusal relationships. Clinical observations of successes and failures associated with the development of techniques and materials have allowed some safe parameters to be delineated for effectively performing dental preparations for ceramic veneers or even placing veneers without any preparation. This article describes the use of an additive diagnostic wax-up that is transferred to the mouth by means of an intraoral mock-up (aesthetic pre-evaluative temporary) with associated mathematic parameters to guide dental preparations. This technique, called Do the Math and presented here in the form of a clinical case report, aims to avoid excessive or incorrect tooth preparation by indicating the exact amount and location of the tooth reduction necessary to attain the desired color and shape.

Cosmic selection rule for the glueball dark matter relic density

NASA Astrophysics Data System (ADS)

Soni, Amarjit; Xiao, Huangyu; Zhang, Yue

2017-10-01

We point out a unique mechanism to produce the relic abundance for the glueball dark matter from a gauged SU (N )d hidden sector which is bridged to the standard model sector through heavy vectorlike quarks colored under gauge interactions from both sides. A necessary ingredient of our assumption is that the vectorlike quarks, produced either thermally or nonthermally, are abundant enough to dominate the universe for some time in the early universe. They later undergo dark color confinement and form unstable vectorlike-quarkonium states which annihilate decay and reheat the visible and dark sectors. The ratio of entropy dumped into two sectors and the final energy budget in the dark glueballs is only determined by low energy parameters, including the intrinsic scale of the dark SU (N )d , Λd, and number of dark colors, Nd, but depend weakly on parameters in the ultraviolet such as the vectorlike quark mass or the initial condition. We call this a cosmic selection rule for the glueball dark matter relic density.

Stochastic bifurcation in a model of love with colored noise

NASA Astrophysics Data System (ADS)

Yue, Xiaokui; Dai, Honghua; Yuan, Jianping

2015-07-01

In this paper, we wish to examine the stochastic bifurcation induced by multiplicative Gaussian colored noise in a dynamical model of love where the random factor is used to describe the complexity and unpredictability of psychological systems. First, the dynamics in deterministic love-triangle model are considered briefly including equilibrium points and their stability, chaotic behaviors and chaotic attractors. Then, the influences of Gaussian colored noise with different parameters are explored such as the phase plots, top Lyapunov exponents, stationary probability density function (PDF) and stochastic bifurcation. The stochastic P-bifurcation through a qualitative change of the stationary PDF will be observed and bifurcation diagram on parameter plane of correlation time and noise intensity is presented to find the bifurcation behaviors in detail. Finally, the top Lyapunov exponent is computed to determine the D-bifurcation when the noise intensity achieves to a critical value. By comparison, we find there is no connection between two kinds of stochastic bifurcation.

Optimization of electrocoagulation process for the treatment of landfill leachate

NASA Astrophysics Data System (ADS)

Huda, N.; Raman, A. A.; Ramesh, S.

2017-06-01

The main problem of landfill leachate is its diverse composition comprising of persistent organic pollutants (POPs) which must be removed before being discharge into the environment. In this study, the treatment of leachate using electrocoagulation (EC) was investigated. Iron was used as both the anode and cathode. Response surface methodology was used for experimental design and to study the effects of operational parameters. Central Composite Design was used to study the effects of initial pH, inter-electrode distance, and electrolyte concentration on color, and COD removals. The process could remove up to 84 % color and 49.5 % COD. The experimental data was fitted onto second order polynomial equations. All three factors were found to be significantly affect the color removal. On the other hand, electrolyte concentration was the most significant parameter affecting the COD removal. Numerical optimization was conducted to obtain the optimum process performance. Further work will be conducted towards integrating EC with other wastewater treatment processes such as electro-Fenton.

Effect of high pressure treatments on the physicochemical properties of a sulphur dioxide-free red wine.

PubMed

Santos, Mickael C; Nunes, Cláudia; Cappelle, João; Gonçalves, Fernando J; Rodrigues, Ana; Saraiva, Jorge A; Coimbra, Manuel A

2013-12-01

The application of high hydrostatic pressure (HHP) in winemaking for substitution of the use of sulphur dioxide is still at a very early stage of development, since knowledge about the effect on physicochemical and sensorial characteristics of the wine during storage is very scarce. In this work, the evolution of colour, antioxidant activity and total phenolic compounds of SO2-free red wines treated by HHP and aged in bottles was followed for 12 months. The pressurised wines were compared with wine samples prepared with addition of 40 ppm of SO2 and without any of these two treatments. After 12 months, the pressurised wines presented higher values of CIELab parameters (a(*), b(*), and L(*)) and a lower monomeric anthocyanin content (45-61%) when compared to the unpressurised ones. The pressurised wines showed also a better global sensorial assessment, with the pressure treatments imparting aged-like characteristics to the wines. The wine deposits of pressurised wines had higher total phenolic content, namely proanthocyanidins (3- to 10-fold). The results demonstrate that HHP can influence long term red wine physicochemical and sensorial characteristics, hypothesised to be due to an increase of condensation reactions of phenolic compounds, forming compounds with higher degree of polymerisation that became insoluble in wine along storage. Copyright © 2013 Elsevier Ltd. All rights reserved.