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Sample records for colour composite images

  1. Ultrasonic colour Doppler imaging

    PubMed Central

    Evans, David H.; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

    2011-01-01

    Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue anatomy. The most common use of the technique is to image the movement of blood through the heart, arteries and veins, but it may also be used to image the motion of solid tissues such as the heart walls. Colour Doppler imaging is now provided on almost all commercial ultrasound machines, and has been found to be of great value in assessing blood flow in many clinical conditions. Although the method for obtaining the velocity information is in many ways similar to the method for obtaining the anatomical information, it is technically more demanding for a number of reasons. It also has a number of weaknesses, perhaps the greatest being that in conventional systems, the velocities measured and thus displayed are the components of the flow velocity directly towards or away from the transducer, while ideally the method would give information about the magnitude and direction of the three-dimensional flow vectors. This review briefly introduces the principles behind colour Doppler imaging and describes some clinical applications. It then describes the basic components of conventional colour Doppler systems and the methods used to derive velocity information from the ultrasound signal. Next, a number of new techniques that seek to overcome the vector problem mentioned above are described. Finally, some examples of vector velocity images are presented. PMID:22866227

  2. Colour thresholding in video imaging.

    PubMed Central

    Fermin, C D; Degraw, S

    1995-01-01

    The basic aspects of video imaging are reviewed as they relate to measurements of histological and anatomical features, with particular emphasis on the advantages and disadvantages of colour and black-and-white imaging modes. In black-and-white imaging, calculations are based on the manipulation of picture elements (pixels) that contain 0-255 levels of information. Black is represented by the absence of light (0) and white by 255 grades of light. In colour imaging, the pixels contain variation of hues for the primary (red, green and blue) and secondary (magenta, yellow, cyan, pink) colours. Manipulation of pixels with colour information is more computer intense than that for black-and-white pixels, because there are over 16 million possible combinations of colour in a system with a 24-bit resolution. The narrow 128 possible grades of separation in black and white often makes distinction between pixels with overlapping intensities difficult. Such difficulty is greatly reduced by colour thresholding of systems that base the representation of colour on a combination of hue-saturation-intensity (HSI) format. Images Fig. 3 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15 Fig. 16 Fig. 17 Fig. 18 Fig. 19 Fig. 20 PMID:7559121

  3. Quantifying Plant Colour and Colour Difference as Perceived by Humans Using Digital Images

    PubMed Central

    Kendal, Dave; Hauser, Cindy E.; Garrard, Georgia E.; Jellinek, Sacha; Giljohann, Katherine M.; Moore, Joslin L.

    2013-01-01

    Human perception of plant leaf and flower colour can influence species management. Colour and colour contrast may influence the detectability of invasive or rare species during surveys. Quantitative, repeatable measures of plant colour are required for comparison across studies and generalisation across species. We present a standard method for measuring plant leaf and flower colour traits using images taken with digital cameras. We demonstrate the method by quantifying the colour of and colour difference between the flowers of eleven grassland species near Falls Creek, Australia, as part of an invasive species detection experiment. The reliability of the method was tested by measuring the leaf colour of five residential garden shrub species in Ballarat, Australia using five different types of digital camera. Flowers and leaves had overlapping but distinct colour distributions. Calculated colour differences corresponded well with qualitative comparisons. Estimates of proportional cover of yellow flowers identified using colour measurements correlated well with estimates obtained by measuring and counting individual flowers. Digital SLR and mirrorless cameras were superior to phone cameras and point-and-shoot cameras for producing reliable measurements, particularly under variable lighting conditions. The analysis of digital images taken with digital cameras is a practicable method for quantifying plant flower and leaf colour in the field or lab. Quantitative, repeatable measurements allow for comparisons between species and generalisations across species and studies. This allows plant colour to be related to human perception and preferences and, ultimately, species management. PMID:23977275

  4. Quantifying plant colour and colour difference as perceived by humans using digital images.

    PubMed

    Kendal, Dave; Hauser, Cindy E; Garrard, Georgia E; Jellinek, Sacha; Giljohann, Katherine M; Moore, Joslin L

    2013-01-01

    Human perception of plant leaf and flower colour can influence species management. Colour and colour contrast may influence the detectability of invasive or rare species during surveys. Quantitative, repeatable measures of plant colour are required for comparison across studies and generalisation across species. We present a standard method for measuring plant leaf and flower colour traits using images taken with digital cameras. We demonstrate the method by quantifying the colour of and colour difference between the flowers of eleven grassland species near Falls Creek, Australia, as part of an invasive species detection experiment. The reliability of the method was tested by measuring the leaf colour of five residential garden shrub species in Ballarat, Australia using five different types of digital camera. Flowers and leaves had overlapping but distinct colour distributions. Calculated colour differences corresponded well with qualitative comparisons. Estimates of proportional cover of yellow flowers identified using colour measurements correlated well with estimates obtained by measuring and counting individual flowers. Digital SLR and mirrorless cameras were superior to phone cameras and point-and-shoot cameras for producing reliable measurements, particularly under variable lighting conditions. The analysis of digital images taken with digital cameras is a practicable method for quantifying plant flower and leaf colour in the field or lab. Quantitative, repeatable measurements allow for comparisons between species and generalisations across species and studies. This allows plant colour to be related to human perception and preferences and, ultimately, species management.

  5. Demosaicing images from colour cameras for digital image correlation

    NASA Astrophysics Data System (ADS)

    Forsey, A.; Gungor, S.

    2016-11-01

    Digital image correlation is not the intended use for consumer colour cameras, but with care they can be successfully employed in such a role. The main obstacle is the sparsely sampled colour data caused by the use of a colour filter array (CFA) to separate the colour channels. It is shown that the method used to convert consumer camera raw files into a monochrome image suitable for digital image correlation (DIC) can have a significant effect on the DIC output. A number of widely available software packages and two in-house methods are evaluated in terms of their performance when used with DIC. Using an in-plane rotating disc to produce a highly constrained displacement field, it was found that the bicubic spline based in-house demosaicing method outperformed the other methods in terms of accuracy and aliasing suppression.

  6. Simulating Colour Vision Deficiency from a Spectral Image.

    PubMed

    Shrestha, Raju

    2016-01-01

    People with colour vision deficiency (CVD) have difficulty seeing full colour contrast and can miss some of the features in a scene. As a part of universal design, researcher have been working on how to modify and enhance the colour of images in order to make them see the scene with good contrast. For this, it is important to know how the original colour image is seen by different individuals with CVD. This paper proposes a methodology to simulate accurate colour deficient images from a spectral image using cone sensitivity of different cases of deficiency. As the method enables generation of accurate colour deficient image, the methodology is believed to help better understand the limitations of colour vision deficiency and that in turn leads to the design and development of more effective imaging technologies for better and wider accessibility in the context of universal design. PMID:27534332

  7. The influence of colour on oculomotor behaviour during image perception.

    PubMed

    von Wartburg, Roman; Ouerhani, Nabil; Pflugshaupt, Tobias; Nyffeler, Thomas; Wurtz, Pascal; Hügli, Heinz; Müri, René M

    2005-09-28

    The aim of this study was to investigate how oculomotor behaviour depends on the availability of colour information in pictorial stimuli. Forty study participants viewed complex images in colour or grey-scale, while their eye movements were recorded. We found two major effects of colour. First, although colour increases the complexity of an image, fixations on colour images were shorter than on their grey-scale versions. This suggests that colour enhances discriminability and thus affects low-level perceptual processing. Second, colour decreases the similarity of spatial fixation patterns between participants. The role of colour on visual attention seems to be more important than previously assumed, in theoretical as well as methodological terms.

  8. Colour appearance descriptors for image browsing and retrieval

    NASA Astrophysics Data System (ADS)

    Othman, Aniza; Martinez, Kirk

    2008-01-01

    In this paper, we focus on the development of whole-scene colour appearance descriptors for classification to be used in browsing applications. The descriptors can classify a whole-scene image into various categories of semantically-based colour appearance. Colour appearance is an important feature and has been extensively used in image-analysis, retrieval and classification. By using pre-existing global CIELAB colour histograms, firstly, we try to develop metrics for whole-scene colour appearance: "colour strength", "high/low lightness" and "multicoloured". Secondly we propose methods using these metrics either alone or combined to classify whole-scene images into five categories of appearance: strong, pastel, dark, pale and multicoloured. Experiments show positive results and that the global colour histogram is actually useful and can be used for whole-scene colour appearance classification. We have also conducted a small-scale human evaluation test on whole-scene colour appearance. The results show, with suitable threshold settings, the proposed methods can describe the whole-scene colour appearance of images close to human classification. The descriptors were tested on thousands of images from various scenes: paintings, natural scenes, objects, photographs and documents. The colour appearance classifications are being integrated into an image browsing system which allows them to also be used to refine browsing.

  9. Variable-rate colour image quantization based on quadtree segmentation

    NASA Astrophysics Data System (ADS)

    Hu, Y. C.; Li, C. Y.; Chuang, J. C.; Lo, C. C.

    2011-09-01

    A novel variable-sized block encoding with threshold control for colour image quantization (CIQ) is presented in this paper. In CIQ, the colour palette used has a great influence on the reconstructed image quality. Typically, a higher image quality and a larger storage cost are obtained when a larger-sized palette is used in CIQ. To cut down the storage cost while preserving quality of the reconstructed images, the threshold control policy for quadtree segmentation is used in this paper. Experimental results show that the proposed method adaptively provides desired bit rates while having better image qualities comparing to CIQ with the usage of multiple palettes of different sizes.

  10. Colour image segmentation using unsupervised clustering technique for acute leukemia images

    NASA Astrophysics Data System (ADS)

    Halim, N. H. Abd; Mashor, M. Y.; Nasir, A. S. Abdul; Mustafa, N.; Hassan, R.

    2015-05-01

    Colour image segmentation has becoming more popular for computer vision due to its important process in most medical analysis tasks. This paper proposes comparison between different colour components of RGB(red, green, blue) and HSI (hue, saturation, intensity) colour models that will be used in order to segment the acute leukemia images. First, partial contrast stretching is applied on leukemia images to increase the visual aspect of the blast cells. Then, an unsupervised moving k-means clustering algorithm is applied on the various colour components of RGB and HSI colour models for the purpose of segmentation of blast cells from the red blood cells and background regions in leukemia image. Different colour components of RGB and HSI colour models have been analyzed in order to identify the colour component that can give the good segmentation performance. The segmented images are then processed using median filter and region growing technique to reduce noise and smooth the images. The results show that segmentation using saturation component of HSI colour model has proven to be the best in segmenting nucleus of the blast cells in acute leukemia image as compared to the other colour components of RGB and HSI colour models.

  11. Ultra-realistic 3-D imaging based on colour holography

    NASA Astrophysics Data System (ADS)

    Bjelkhagen, H. I.

    2013-02-01

    A review of recent progress in colour holography is provided with new applications. Colour holography recording techniques in silver-halide emulsions are discussed. Both analogue, mainly Denisyuk colour holograms, and digitally-printed colour holograms are described and their recent improvements. An alternative to silver-halide materials are the panchromatic photopolymer materials such as the DuPont and Bayer photopolymers which are covered. The light sources used to illuminate the recorded holograms are very important to obtain ultra-realistic 3-D images. In particular the new light sources based on RGB LEDs are described. They show improved image quality over today's commonly used halogen lights. Recent work in colour holography by holographers and companies in different countries around the world are included. To record and display ultra-realistic 3-D images with perfect colour rendering are highly dependent on the correct recording technique using the optimal recording laser wavelengths, the availability of improved panchromatic recording materials and combined with new display light sources.

  12. Synaesthetic Colour in the Brain: Beyond Colour Areas. A Functional Magnetic Resonance Imaging Study of Synaesthetes and Matched Controls

    PubMed Central

    van Leeuwen, Tessa M.; Petersson, Karl Magnus; Hagoort, Peter

    2010-01-01

    Background In synaesthesia, sensations in a particular modality cause additional experiences in a second, unstimulated modality (e.g., letters elicit colour). Understanding how synaesthesia is mediated in the brain can help to understand normal processes of perceptual awareness and multisensory integration. In several neuroimaging studies, enhanced brain activity for grapheme-colour synaesthesia has been found in ventral-occipital areas that are also involved in real colour processing. Our question was whether the neural correlates of synaesthetically induced colour and real colour experience are truly shared. Methodology/Principal Findings First, in a free viewing functional magnetic resonance imaging (fMRI) experiment, we located main effects of synaesthesia in left superior parietal lobule and in colour related areas. In the left superior parietal lobe, individual differences between synaesthetes (projector-associator distinction) also influenced brain activity, confirming the importance of the left superior parietal lobe for synaesthesia. Next, we applied a repetition suppression paradigm in fMRI, in which a decrease in the BOLD (blood-oxygenated-level-dependent) response is generally observed for repeated stimuli. We hypothesized that synaesthetically induced colours would lead to a reduction in BOLD response for subsequently presented real colours, if the neural correlates were overlapping. We did find BOLD suppression effects induced by synaesthesia, but not within the colour areas. Conclusions/Significance Because synaesthetically induced colours were not able to suppress BOLD effects for real colour, we conclude that the neural correlates of synaesthetic colour experience and real colour experience are not fully shared. We propose that synaesthetic colour experiences are mediated by higher-order visual pathways that lie beyond the scope of classical, ventral-occipital visual areas. Feedback from these areas, in which the left parietal cortex is likely to

  13. Colour stability and visual perception of dimethacrylate based dental composite resins.

    PubMed

    Cook, W D; Chong, M P

    1985-07-01

    The spectrophotometric method of colour measurement was applied to an investigation of the colour stability of dimethacrylate based composite resins exposed to thermal and photochemical aging. A good correlation was observed between visual perception of colour change and the spectrophotometric colour difference [delta E (FMC-2)] of unexposed and aged specimens, but 50% of the observers considered the colour match of two specimens to be clinically unacceptable when the colour difference exceeded 10.6. Kinetic studies of thermally and photochemically induced colour change showed a sigmoidal dependence of colour change on the logarithm of exposure time. Because the direction and magnitude of the colour change differed for the two procedures, it would appear that different mechanisms are involved.

  14. Colour imaging in the monitoring and documentation of choroidal naevi. Are Optomap colour images adequate for this purpose?

    PubMed

    Paul Brett, Jonathan; Lake, Amy; Downes, Susan

    2016-01-01

    An audit project to evaluate and compare three different imaging systems used to photograph choroidal naevi and to determine whether the Optos Optomap(®) can be used as the only colour image capture system for monitoring and documenting choroidal naevi. A further aim was to assess whether existing protocols could be improved to accurately document position and appearance of choroidal naevi. Twenty patients with choroidal naevi were photographed on three different colour image capture systems. Colour images were taken on the Optomap(®) wide field P200MA camera; the Zeiss FF450plus(®) mydriatic camera and the Topcon TRC-NW6S(®). All images were reviewed retrospectively by a medical retina consultant (SD) who completed a questionnaire to determine the most effective photographic system(s) in demonstrating the location of the naevi and the features of the condition. The Optomap(®) was the most effective in pinpointing the location of the naevus and the Zeiss FF450plus mydriatic camera best captured the features of the naevus. The non-mydriatic camera was rated the least satisfactory for both tasks. The location of the naevus on the retina should determine the choice of modality. If it is possible to photograph the lesion and include the optic disc or central macula, then the mydriatic camera is considered the best modality for recording both the position and features of the pathology. However, if it is not possible, because of the location, to include both the disc or central macula with the lesion in the same frame, then the Optomap(®) should be used to photograph the naevus to record its position and ideally a colour image on the mydriatic camera should also be taken to record the appearance of the lesion. PMID:27253508

  15. Calculation of colour resulting from composite/compomer layering techniques.

    PubMed

    Lee, Y-K; Powers, J M

    2004-11-01

    This study determined the influence of optical properties of constituent layers on the colour of double-layer aesthetic filling materials. Multiple regression equations for the Commission Internationale de I'Eclairage (CIE) L*, a* and b* of layered materials were calculated from the optical values of the covering and underlying layers. Specimens (10 mm diameter, 1 mm thickness) of two light-cured resin composites and one compomer of seven to 11 shades were used. CIE L*, a* and b* values of each specimen were measured with a colour spectrophotometer backed by a standard white background. The scattering coefficient (S), absorption coefficient (K), contrast ratio (C) and translucency parameter (T) were calculated. Double-layered specimens were formed in optical contact by joining two different shades from the same material, or resin composite as covering with a compomer underlying layer. Each of the L*, a* and b* of layered material was used as a dependent variable, and 14 optical values of underlying and covering layers were used as independent variables in forward regression analysis (P = 0.01). CIE L* after layering had a positive correlation with S of covering layer (correlation coefficient; beta = 0.79-0.91, P < 0.01) and a correlation with L* of underlying layer (beta = 0.14-0.16). CIE a* after layering had a correlation with a* of covering layer (beta = 0.83-0.94) and a correlation with a* of underlying layer (beta = 0.30-0.56). CIE b* after layering had a correlation with b* of covering layer (beta = 0.77-0.90) and a correlation with T of covering layer (beta = 0.40-0.59). The layered colour of these materials can be predicted by the derived regression equations within the limitations of this study. CIE L*, a* and b* values of double-layer material are mainly influenced by S, CIE a* and b* of covering layer, respectively.

  16. Deepest Wide-Field Colour Image in the Southern Sky

    NASA Astrophysics Data System (ADS)

    2003-01-01

    LA SILLA CAMERA OBSERVES CHANDRA DEEP FIELD SOUTH ESO PR Photo 02a/03 ESO PR Photo 02a/03 [Preview - JPEG: 400 x 437 pix - 95k] [Normal - JPEG: 800 x 873 pix - 904k] [HiRes - JPEG: 4000 x 4366 pix - 23.1M] Caption : PR Photo 02a/03 shows a three-colour composite image of the Chandra Deep Field South (CDF-S) , obtained with the Wide Field Imager (WFI) camera on the 2.2-m MPG/ESO telescope at the ESO La Silla Observatory (Chile). It was produced by the combination of about 450 images with a total exposure time of nearly 50 hours. The field measures 36 x 34 arcmin 2 ; North is up and East is left. Technical information is available below. The combined efforts of three European teams of astronomers, targeting the same sky field in the southern constellation Fornax (The Oven) have enabled them to construct a very deep, true-colour image - opening an exceptionally clear view towards the distant universe . The image ( PR Photo 02a/03 ) covers an area somewhat larger than the full moon. It displays more than 100,000 galaxies, several thousand stars and hundreds of quasars. It is based on images with a total exposure time of nearly 50 hours, collected under good observing conditions with the Wide Field Imager (WFI) on the MPG/ESO 2.2m telescope at the ESO La Silla Observatory (Chile) - many of them extracted from the ESO Science Data Archive . The position of this southern sky field was chosen by Riccardo Giacconi (Nobel Laureate in Physics 2002) at a time when he was Director General of ESO, together with Piero Rosati (ESO). It was selected as a sky region towards which the NASA Chandra X-ray satellite observatory , launched in July 1999, would be pointed while carrying out a very long exposure (lasting a total of 1 million seconds, or 278 hours) in order to detect the faintest possible X-ray sources. The field is now known as the Chandra Deep Field South (CDF-S) . The new WFI photo of CDF-S does not reach quite as deep as the available images of the "Hubble Deep Fields

  17. Colour perfusion imaging: a new application of computed tomography.

    PubMed

    Miles, K A; Hayball, M; Dixon, A K

    1991-03-16

    We describe a new application for imaging with computed tomography (CT) in which a quantifiable map of tissue perfusion is created and displayed by means of a colour scale. A rapid sequence of images is acquired without table movement immediately after a bolus intravenous injection of radiographic contrast medium. The rate of enhancement in each pixel within the chosen slice can then be used to determine perfusion. The technique provides a quantifiable display of regional perfusion combined with the high spatial resolution afforded by CT.

  18. Robust colour calibration of an imaging system using a colour space transform and advanced regression modelling.

    PubMed

    Jackman, Patrick; Sun, Da-Wen; Elmasry, Gamal

    2012-08-01

    A new algorithm for the conversion of device dependent RGB colour data into device independent L*a*b* colour data without introducing noticeable error has been developed. By combining a linear colour space transform and advanced multiple regression methodologies it was possible to predict L*a*b* colour data with less than 2.2 colour units of error (CIE 1976). By transforming the red, green and blue colour components into new variables that better reflect the structure of the L*a*b* colour space, a low colour calibration error was immediately achieved (ΔE(CAL) = 14.1). Application of a range of regression models on the data further reduced the colour calibration error substantially (multilinear regression ΔE(CAL) = 5.4; response surface ΔE(CAL) = 2.9; PLSR ΔE(CAL) = 2.6; LASSO regression ΔE(CAL) = 2.1). Only the PLSR models deteriorated substantially under cross validation. The algorithm is adaptable and can be easily recalibrated to any working computer vision system. The algorithm was tested on a typical working laboratory computer vision system and delivered only a very marginal loss of colour information ΔE(CAL) = 2.35. Colour features derived on this system were able to safely discriminate between three classes of ham with 100% correct classification whereas colour features measured on a conventional colourimeter were not.

  19. Structural colour printing from a reusable generic nanosubstrate masked for the target image.

    PubMed

    Rezaei, M; Jiang, H; Kaminska, B

    2016-02-26

    Structural colour printing has advantages over traditional pigment-based colour printing. However, the high fabrication cost has hindered its applications in printing large-area images because each image requires patterning structural pixels in nanoscale resolution. In this work, we present a novel strategy to print structural colour images from a pixelated substrate which is called a nanosubstrate. The nanosubstrate is fabricated only once using nanofabrication tools and can be reused for printing a large quantity of structural colour images. It contains closely packed arrays of nanostructures from which red, green, blue and infrared structural pixels can be imprinted. To print a target colour image, the nanosubstrate is first covered with a mask layer to block all the structural pixels. The mask layer is subsequently patterned according to the target colour image to make apertures of controllable sizes on top of the wanted primary colour pixels. The masked nanosubstrate is then used as a stamp to imprint the colour image onto a separate substrate surface using nanoimprint lithography. Different visual colours are achieved by properly mixing the red, green and blue primary colours into appropriate ratios controlled by the aperture sizes on the patterned mask layer. Such a strategy significantly reduces the cost and complexity of printing a structural colour image from lengthy nanoscale patterning into high throughput micro-patterning and makes it possible to apply structural colour printing in personalized security features and data storage. In this paper, nanocone array grating pixels were used as the structural pixels and the nanosubstrate contains structures to imprint the nanocone arrays. Laser lithography was implemented to pattern the mask layer with submicron resolution. The optical properties of the nanocone array gratings are studied in detail. Multiple printed structural colour images with embedded covert information are demonstrated. PMID:26820913

  20. Structural colour printing from a reusable generic nanosubstrate masked for the target image

    NASA Astrophysics Data System (ADS)

    Rezaei, M.; Jiang, H.; Kaminska, B.

    2016-02-01

    Structural colour printing has advantages over traditional pigment-based colour printing. However, the high fabrication cost has hindered its applications in printing large-area images because each image requires patterning structural pixels in nanoscale resolution. In this work, we present a novel strategy to print structural colour images from a pixelated substrate which is called a nanosubstrate. The nanosubstrate is fabricated only once using nanofabrication tools and can be reused for printing a large quantity of structural colour images. It contains closely packed arrays of nanostructures from which red, green, blue and infrared structural pixels can be imprinted. To print a target colour image, the nanosubstrate is first covered with a mask layer to block all the structural pixels. The mask layer is subsequently patterned according to the target colour image to make apertures of controllable sizes on top of the wanted primary colour pixels. The masked nanosubstrate is then used as a stamp to imprint the colour image onto a separate substrate surface using nanoimprint lithography. Different visual colours are achieved by properly mixing the red, green and blue primary colours into appropriate ratios controlled by the aperture sizes on the patterned mask layer. Such a strategy significantly reduces the cost and complexity of printing a structural colour image from lengthy nanoscale patterning into high throughput micro-patterning and makes it possible to apply structural colour printing in personalized security features and data storage. In this paper, nanocone array grating pixels were used as the structural pixels and the nanosubstrate contains structures to imprint the nanocone arrays. Laser lithography was implemented to pattern the mask layer with submicron resolution. The optical properties of the nanocone array gratings are studied in detail. Multiple printed structural colour images with embedded covert information are demonstrated.

  1. Applying colour science in colour design

    NASA Astrophysics Data System (ADS)

    Luo, Ming Ronnier

    2006-06-01

    Although colour science has been widely used in a variety of industries over the years, it has not been fully explored in the field of product design. This paper will initially introduce the three main application fields of colour science: colour specification, colour-difference evaluation and colour appearance modelling. By integrating these advanced colour technologies together with modern colour imaging devices such as display, camera, scanner and printer, some computer systems have been recently developed to assist designers for designing colour palettes through colour selection by means of a number of widely used colour order systems, for creating harmonised colour schemes via a categorical colour system, for generating emotion colours using various colour emotional scales and for facilitating colour naming via a colour-name library. All systems are also capable of providing accurate colour representation on displays and output to different imaging devices such as printers.

  2. Influence of Different Drinks on the Colour Stability of Dental Resin Composites

    PubMed Central

    Topcu, Fulya Toksoy; Sahinkesen, Gunes; Yamanel, Kivanc; Erdemir, Ugur; Oktay, Elif Aybala; Ersahan, Seyda

    2009-01-01

    Objectives The objective of this study was to evaluate the discolouration effects of artificial saliva, granule lemon juice, coffee (without sugar), coca cola, sour cherry juice, fresh carrot juice and red wine on resin-based composite materials that are commonly used in restorative dentistry. Methods Colour of four brands of resin composites (Filtek Z 250 (3M Espe), Filtek Supreme (3M Espe), Quadrant (Cavex), Charisma (Heraeus-Kulzer)) of A2 shade was measured after one day of immersion in eight different solutions. Colour measurements were obtained by using a XL-20 Trismus Colourimeter and colour differences (ΔE) were estimated. For statistical evaluation, analysis of variance (ANOVA), Dunnett and Tukey tests were used at a significance level of 0.05. Results For the four restorative materials tested, the lowest ΔE values were observed in the artificial saliva, while ΔE values were the highest in red wine group. When comparing the four different restorative materials, Filtek Supreme exhibited the least colour changes whereas Filtek Z250 was the least colour-stable. Conclusions Dental resin composites and drinking solutions were significant factors that may affect the colour stability. After immersion for one day, all materials showed visible colour changes. The red wine solution exhibited more staining than others in three groups. Filtek Supreme showed significantly the least colour change due to its nano particle sizes. PMID:19262731

  3. Making colourful sense of Raman images of single cells.

    PubMed

    Ashton, Lorna; Hollywood, Katherine A; Goodacre, Royston

    2015-03-21

    In order to understand biological systems it is important to gain pertinent information on the spatial localisation of chemicals within cells. With the relatively recent advent of high-resolution chemical imaging this is being realised and one rapidly developing area of research is the Raman mapping of single cells, an approach whose success has vast potential for numerous areas of biomedical research. However, there is a danger of undermining the potential routine use of Raman mapping due to a lack of consistency and transparency in the way false-shaded Raman images are constructed. In this study we demonstrate, through the use of simulated data and real Raman maps of single human keratinocyte (HaCaT) cells, how changes in the application of colour shading can dramatically alter the final Raman images. In order to avoid ambiguity and potential subjectivity in image interpretation we suggest that data distribution plots are used to aid shading approaches and that extreme care is taken to use the most appropriate false-shading for the biomedical question under investigation.

  4. Ripening of salami: assessment of colour and aspect evolution using image analysis and multivariate image analysis.

    PubMed

    Fongaro, Lorenzo; Alamprese, Cristina; Casiraghi, Ernestina

    2015-03-01

    During ripening of salami, colour changes occur due to oxidation phenomena involving myoglobin. Moreover, shrinkage due to dehydration results in aspect modifications, mainly ascribable to fat aggregation. The aim of this work was the application of image analysis (IA) and multivariate image analysis (MIA) techniques to the study of colour and aspect changes occurring in salami during ripening. IA results showed that red, green, blue, and intensity parameters decreased due to the development of a global darker colour, while Heterogeneity increased due to fat aggregation. By applying MIA, different salami slice areas corresponding to fat and three different degrees of oxidised meat were identified and quantified. It was thus possible to study the trend of these different areas as a function of ripening, making objective an evaluation usually performed by subjective visual inspection.

  5. Effect of fining on the colour and pigment composition of young red wines.

    PubMed

    González-Neves, Gustavo; Favre, Guzmán; Gil, Graciela

    2014-08-15

    This work aimed to evaluate the effect of four fining agents on the colour and pigment composition of red wines of Tannat. The wines were analysed 15 days after fining and immediately after separation of sediments and bottling. Colour was evaluated by spectrophotometry and polyphenols were analysed by spectrophotometry and HPLC-DAD. The colour intensity of wine was significantly decreased by bentonite and egg albumin. The most remarkable effects on wine phenolic composition were produced by bentonite and gelatin, which significantly decreased anthocyanin and tannin concentrations, respectively. Results show that each fining agent has very different impact on the wine attributes, and their effects depended as well on the composition of the clarified wine. The use of non-traditional agents of fining, as vegetable proteins, may have less impact on the colour and anthocyanin content of red wines.

  6. Dynamic application of digital image and colour processing in characterizing flame radiation features

    NASA Astrophysics Data System (ADS)

    Huang, Hua Wei; Zhang, Yang

    2010-08-01

    In this work, the experimental investigation of the dynamic flame properties of flame flickering and equivalence ratio sensing of a combustion process was done. In particular, the time-varied flame properties were examined using a novel digital image and colour processing methodology. This technique makes use of the observed correlation between a digital image colour signal and physical flame radiation characteristics in the visible wavelength domain. Aspects of RGB and HSV colour modelling principles were applied to show that the addition of colour identification in the image processing of high-speed flame image data could yield three useful parameters which are related to the dynamic behaviour of different flame emanating components. First, the validity of the colour identities for tracking the yellowish-red diffusion and greenish-blue premixed flame colourations were examined by comparing their respective flickering frequency profiles. Then, the usefulness of the extracted Rdiffusion, Gpremixed and Bpremixed colour signals to abstractly represent the behaviour of soot, C2* and CH* emission characteristics in a dynamic flame transition from diffusion to stoichiometric premixed condition was demonstrated. In particular, the colour signal ratio Bpremixed/Gpremixed was correlated to exemplify the approximate time-varied state of the equivalence ratio from the imaged combustion phenomenon.

  7. Composition of pigments and colour changes in green table olives related to processing type.

    PubMed

    Ramírez, Eva; Gandul-Rojas, Beatriz; Romero, Concepción; Brenes, Manuel; Gallardo-Guerrero, Lourdes

    2015-01-01

    Brownish colourations in Natural green table olives (non-treated with alkali) make this product less attractive to consumers than Spanish-style green table olives (treated with alkali), which develop a more appreciated bright golden-yellow colour. These colour differences were studied in relation to changes in the composition of chlorophyll and carotenoid pigments, as well as polyphenolic compounds and polyphenol oxidase enzyme (PPO) activity. Natural green olives showed a different chlorophyll profile than Spanish-style. However, all the chlorophyll pigments formed in both processing types were Mg-free derivatives (mostly pheophytins) with similar colourations, ranging from grey to green brownish. In the carotenoid fraction no appreciable differences were found between both processing types. The fruit's brownish colour was mainly due to polymeric substances with a size of >1000 daltons and polyphenolic nature, resulting from an enzymatic oxidation by PPO of the o-diphenolic compounds present in the fresh fruits.

  8. Analysis of the ignition process using a digital image and colour processing technique

    NASA Astrophysics Data System (ADS)

    Huang, Hua Wei; Zhang, Yang

    2011-07-01

    An experimental investigation of flame emission properties in the ignition-to-flame propagation process has been conducted. In particular, the phenomenon of ignition delay was analysed through digital image processing and colour analysis. This processing methodology makes use of the observed correlation between a digital colour signal and physical flame emission characteristics in the visible spectrum. Aspects of red, green, blue and hue, saturation, value colour modelling principles were combined to turn a high-speed digital colour camera into an abstract multi-spectral system. Experiments were carried out on both a laboratory-based atmospheric burner and an industrial gas-turbine combustor. In both cases, results have shown that the commonly observed flame colour feature from the soot radiation does not signify the start of combustion reaction but rather a later stage of flame development. Additional weak colour quantities were identified via digital colour image processing in the ignition delay time interval where there were no previous definitive signals to designate the presence of combustion. This colour entity was found to match with the typical digital colour signal output from the stimulation of CH* and C2* radical chemiluminescence emissions.

  9. Global Interior Robot Localisation by a Colour Content Image Retrieval System

    NASA Astrophysics Data System (ADS)

    Chaari, A.; Lelandais, S.; Montagne, C.; Ahmed, M. Ben

    2007-12-01

    We propose a new global localisation approach to determine a coarse position of a mobile robot in structured indoor space using colour-based image retrieval techniques. We use an original method of colour quantisation based on the baker's transformation to extract a two-dimensional colour pallet combining as well space and vicinity-related information as colourimetric aspect of the original image. We conceive several retrieving approaches bringing to a specific similarity measure [InlineEquation not available: see fulltext.] integrating the space organisation of colours in the pallet. The baker's transformation provides a quantisation of the image into a space where colours that are nearby in the original space are also nearby in the output space, thereby providing dimensionality reduction and invariance to minor changes in the image. Whereas the distance [InlineEquation not available: see fulltext.] provides for partial invariance to translation, sight point small changes, and scale factor. In addition to this study, we developed a hierarchical search module based on the logic classification of images following rooms. This hierarchical module reduces the searching indoor space and ensures an improvement of our system performances. Results are then compared with those brought by colour histograms provided with several similarity measures. In this paper, we focus on colour-based features to describe indoor images. A finalised system must obviously integrate other type of signature like shape and texture.

  10. Fundus autofluorescence and colour fundus imaging compared during telemedicine screening in patients with diabetes.

    PubMed

    Kolomeyer, Anton M; Baumrind, Benjamin R; Szirth, Bernard C; Shahid, Khadija; Khouri, Albert S

    2013-06-01

    We investigated the use of fundus autofluorescence (FAF) imaging in screening the eyes of patients with diabetes. Images were obtained from 50 patients with type 2 diabetes undergoing telemedicine screening with colour fundus imaging. The colour and FAF images were obtained with a 15.1 megapixel non-mydriatic retinal camera. Colour and FAF images were compared for pathology seen in nonproliferative and proliferative diabetic retinopathy (NPDR and PDR, respectively). A qualitative assessment was made of the ease of detecting early retinopathy changes and the extent of existing retinopathy. The mean age of the patients was 47 years, most were male (82%) and most were African American (68%). Their mean visual acuity was 20/45 and their mean intraocular pressure was 14.3 mm Hg. Thirty-eight eyes (76%) did not show any diabetic retinopathy changes on colour or FAF imaging. Seven patients (14%) met the criteria for NPDR and five (10%) for severe NPDR or PDR. The most common findings were microaneurysms, hard exudates and intra-retinal haemorrhages (IRH) (n = 6 for each). IRH, microaneurysms and chorioretinal scars were more easily visible on FAF images. Hard exudates, pre-retinal haemorrhage and fibrosis, macular oedema and Hollenhorst plaque were easier to identify on colour photographs. The value of FAF imaging as a complementary technique to colour fundus imaging in detecting diabetic retinopathy during ocular screening warrants further investigation.

  11. Hundred metre virtual telescope captures unique detailed colour image

    NASA Astrophysics Data System (ADS)

    2009-02-01

    A team of French astronomers has captured one of the sharpest colour images ever made. They observed the star T Leporis, which appears, on the sky, as small as a two-storey house on the Moon [1]. The image was taken with ESO's Very Large Telescope Interferometer (VLTI), emulating a virtual telescope about 100 metres across and reveals a spherical molecular shell around an aged star. ESO PR Photo 06a/09 The star T Leporis as seen with VLTI ESO PR Photo 06b/09 The star T Leporis to scale ESO PR Photo 06c/09 A virtual 100-metre telescope ESO PR Photo 06d/09 The orbit of Theta1 Orionis C ESO PR Video 06a/09 Zoom-in onto T Leporis "This is one of the first images made using near-infrared interferometry," says lead author Jean-Baptiste Le Bouquin. Interferometry is a technique that combines the light from several telescopes, resulting in a vision as sharp as that of a giant telescope with a diameter equal to the largest separation between the telescopes used. Achieving this requires the VLTI system components to be positioned to an accuracy of a fraction of a micrometre over about 100 metres and maintained so throughout the observations -- a formidable technical challenge. When doing interferometry, astronomers must often content themselves with fringes, the characteristic pattern of dark and bright lines produced when two beams of light combine, from which they can model the physical properties of the object studied. But, if an object is observed on several runs with different combinations and configurations of telescopes, it is possible to put these results together to reconstruct an image of the object. This is what has now been done with ESO's VLTI, using the 1.8-metre Auxiliary Telescopes. "We were able to construct an amazing image, and reveal the onion-like structure of the atmosphere of a giant star at a late stage of its life for the first time," says Antoine Mérand, member of the team. "Numerical models and indirect data have allowed us to imagine the

  12. Influence of bottle storage time on colour, phenolic composition and sensory properties of sweet red wines.

    PubMed

    Marquez, Ana; Serratosa, Maria P; Merida, Julieta

    2014-03-01

    Changes in colour and phenolic composition in sweet red wines made from Merlot, Syrah and Tempranillo grapes were studied in order to assess the influence of bottle storage over a period of 12months. For this purpose, wine colour parameters, sensory analysis and concentrations of monomeric anthocyanins, pyranoanthocyanins, methylmethine-mediated condensation adducts, flavan3-ol derivatives and flavonols were measured. Hue increased and red colours decreased with the storage time, particularly over the first 3months. The concentrations of low molecular weight flavan-3-ol derivatives decreased with time due to the effect of their conversion into tannins of high molecular weight. In addition, the glycosylated flavonols decreased through hydrolysis to give the corresponding aglycones. Overall, the concentration of phenolic compounds decreased markedly with storage time, whereas the antioxidant activity in the wines remained constant throughout. A panel of expert tasters judged the colour, aroma and flavour of all initial and final wines to be acceptable.

  13. Organic-on-silicon complementary metal–oxide–semiconductor colour image sensors

    PubMed Central

    Lim, Seon-Jeong; Leem, Dong-Seok; Park, Kyung-Bae; Kim, Kyu-Sik; Sul, Sangchul; Na, Kyoungwon; Lee, Gae Hwang; Heo, Chul-Joon; Lee, Kwang-Hee; Bulliard, Xavier; Satoh, Ryu-Ichi; Yagi, Tadao; Ro, Takkyun; Im, Dongmo; Jung, Jungkyu; Lee, Myungwon; Lee, Tae-Yon; Han, Moon Gyu; Jin, Yong Wan; Lee, Sangyoon

    2015-01-01

    Complementary metal–oxide–semiconductor (CMOS) colour image sensors are representative examples of light-detection devices. To achieve extremely high resolutions, the pixel sizes of the CMOS image sensors must be reduced to less than a micron, which in turn significantly limits the number of photons that can be captured by each pixel using silicon (Si)-based technology (i.e., this reduction in pixel size results in a loss of sensitivity). Here, we demonstrate a novel and efficient method of increasing the sensitivity and resolution of the CMOS image sensors by superposing an organic photodiode (OPD) onto a CMOS circuit with Si photodiodes, which consequently doubles the light-input surface area of each pixel. To realise this concept, we developed organic semiconductor materials with absorption properties selective to green light and successfully fabricated highly efficient green-light-sensitive OPDs without colour filters. We found that such a top light-receiving OPD, which is selective to specific green wavelengths, demonstrates great potential when combined with a newly designed Si-based CMOS circuit containing only blue and red colour filters. To demonstrate the effectiveness of this state-of-the-art hybrid colour image sensor, we acquired a real full-colour image using a camera that contained the organic-on-Si hybrid CMOS colour image sensor. PMID:25578322

  14. Blind colour separation of H&E stained histological images by linearly transforming the colour space.

    PubMed

    Celis, R; Romo, D; Romero, E

    2015-12-01

    Blind source separation methods aim to split information into the original sources. In histology, each dye component attempts to specifically characterize different microscopic structures. In the case of the hematoxylin-eosin stain, universally used for routine examination, quantitative analysis may often require the inspection of different morphological signatures related mainly to nuclei patterns, but also to stroma distribution. Stain separation is usually a preprocessing operation that is transversal to different applications. This paper presents a novel colour separation method that finds the hematoxylin and eosin clusters by projecting the whole (r,g,b) space to a folded surface connecting the distributions of a series of [(r-b),g] planes that divide the cloud of H&E tones. The proposed method produces density maps closer to those obtained with the colour mixing matrices set by an expert, when comparing with the density maps obtained using nonnegative matrix factorization (NMF), independent component analysis (ICA) and a state-of-the-art method. The method has outperformed three baseline methods, NMF, Macenko and ICA, in about 8%, 12% and 52% for the eosin component, whereas this was about 4%, 8% and 26% for the hematoxylin component. PMID:26356123

  15. Multi-colour microscopic interferometry for optical metrology and imaging applications

    NASA Astrophysics Data System (ADS)

    Upputuri, Paul Kumar; Pramanik, Manojit; Nandigana, Krishna Mohan; Kothiyal, Mahendra Prasad

    2016-09-01

    Interferometry has been widely used for optical metrology and imaging applications because of their precision, reliability, and versatility. Although single-wavelength interferometery can provide high sensitivity and resolution, it has several drawbacks, namely, it fails to quantify large-discontinuities, large-deformations, and shape of unpolished surfaces. Multiple-wavelength techniques have been successfully used to overcome the drawbacks associated with single wavelength analysis. The use of colour CCD camera allows simultaneous acquisition of multiple interferograms. The advances in colour CCD cameras and image processing techniques have made the multi-colour interferometry a faster, simpler, and cost-effective tool for industrial applications. This article reviews the recent advances in multi-colour interferometric techniques and their demanding applications for characterization of micro-systems, non-destructive testing, and bio-imaging applications.

  16. Visualization of complex flow fields, with application to the interpretation of colour flow Doppler images.

    PubMed

    Vera, N; Steinman, D A; Ethier, C R; Johnston, K W; Cobbold, R S

    1992-01-01

    The interpretation of colour flow Doppler images in regions of complex flow can be difficult. To aid in such interpretations, we have developed software which accepts as input the results of a fluid flow simulation program and produces simulated colour flow Doppler images on a workstation. This allows direct comparison between well-described flow fields and colour flow Doppler images. Application of this approach is demonstrated for flow in a two-dimensional model of a distal graft-to-vessel anastomosis, and the interpretation of the results for three-dimensional flows is briefly discussed. In addition, a method for presenting two-dimensional (vectorial) velocity data via colour coding is presented.

  17. Colour space influence for vegetation image classification application to Caribbean forest and agriculture

    NASA Astrophysics Data System (ADS)

    Abadi, M.; Grandchamp, E.

    2008-10-01

    This paper deals with a comparison of different colour space in order to improve high resolution images classification. The background of this study is the measure of the agriculture impact on the environment in islander context. Biodiversity is particularly sensitive and relevant in such areas and the follow-up of the forest front is a way to ensure its preservation. Very high resolution satellite images are used such as QuickBird and IKONOS scenes. In order to segment the images into forest and agriculture areas, we characterize both ground covers with colour and texture features. A classical unsupervised classifier is then used to obtain labelled areas. As features are computed on coloured images, we can wonder if the colour space choice is relevant. This study has been made considering more than fourteen colour spaces (RGB, YUV, Lab, YIQ, YCrCs, XYZ, CMY, LMS, HSL, KLT, IHS, I1I2I3, HSV, HSI, etc.) and shows the visual and quantitative superiority of IHS on all others. For conciseness reasons, results only show RGB, I1I2I3 and IHS colour spaces.

  18. Measuring grinding surface roughness based on the sharpness evaluation of colour images

    NASA Astrophysics Data System (ADS)

    Huaian, Y. I.; Jian, L. I. U.; Enhui, L. U.; Peng, A. O.

    2016-02-01

    Current machine vision-based detection methods for metal surface roughness mainly use the grey values of images for statistical analysis but do not make full use of the colour information and ignore the subjective judgment of the human vision system. To address these problems, this paper proposes a method to measure surface roughness through the sharpness evaluation of colour images. Based on the difference in sharpness of virtual images of colour blocks that are formed on grinding surfaces with different roughness, an algorithm for evaluating the sharpness of colour images that is based on the difference of the RGB colour space was used to develop a correlation model between the sharpness and the surface roughness. The correlation model was analysed under two conditions: constant illumination and varying illumination. The effect of the surface textures of the grinding samples on the image sharpness was also considered, demonstrating the feasibility of the detection method. The results show that the sharpness is strongly correlated with the surface roughness; when the illumination and the surface texture have the same orientation, the sharpness clearly decreases with increasing surface roughness. Under varying illumination, this correlation between the sharpness and surface roughness was highly robust, and the sharpness of each virtual image increased linearly with the illumination. Relative to the detection method for surface roughness using gray level co-occurrence matrix or artificial neural network, the proposed method is convenient, highly accurate and has a wide measurement range.

  19. Image Size Scalable Full-parallax Coloured Three-dimensional Video by Electronic Holography

    NASA Astrophysics Data System (ADS)

    Sasaki, Hisayuki; Yamamoto, Kenji; Ichihashi, Yasuyuki; Senoh, Takanori

    2014-02-01

    In electronic holography, various methods have been considered for using multiple spatial light modulators (SLM) to increase the image size. In a previous work, we used a monochrome light source for a method that located an optical system containing lens arrays and other components in front of multiple SLMs. This paper proposes a colourization technique for that system based on time division multiplexing using laser light sources of three colours (red, green, and blue). The experimental device we constructed was able to perform video playback (20 fps) in colour of full parallax holographic three-dimensional (3D) images with an image size of 63 mm and a viewing-zone angle of 5.6 degrees without losing any part of the 3D image.

  20. Colour stability, opacity and cross-link density of composites submitted to accelerated artificial aging.

    PubMed

    Mundim, Fabrício Mariano; Pires-de-Souza, Fernanda de Carvalho Panzeri; Garcia, Lucas da Fonseca Roberti; Consani, Simonides

    2010-06-01

    The study evaluated the influence of accelerated artificial aging on colour stability, opacity and cross-link density of resin-based composites (RBCs). Seven specimens were obtained of five RBCs (Heliomolar, 4 Seasons, Tetric Evo Ceram, SR Adoro), which were submitted to colour stability and opacity analysis and cross-link density evaluation. All tests were performed before and after aging. After statistical analysis (one-way ANOVA; Tukey; p<0.05), it was observed that QuiXfil and SR Adoro presented colour alteration values above those that are clinically acceptable (deltaE=5.77 and 4.34 respectively) and the variation in opacity was lowest for SR Adoro. There was an increase in the cross-link density of all studied materials after aging.

  1. Pseudo colour visualization of fused multispectral laser scattering images for optical diagnosis of rheumatoid arthritis

    NASA Astrophysics Data System (ADS)

    Zabarylo, U.; Minet, O.

    2010-01-01

    Investigations on the application of optical procedures for the diagnosis of rheumatism using scattered light images are only at the beginning both in terms of new image-processing methods and subsequent clinical application. For semi-automatic diagnosis using laser light, the multispectral scattered light images are registered and overlapped to pseudo-coloured images, which depict diagnostically essential contents by visually highlighting pathological changes.

  2. 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

  3. 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.

  4. Improved discrimination among similar agricultural plots using red-and-green-based pseudo-colour imaging

    NASA Astrophysics Data System (ADS)

    Doi, Ryoichi

    2016-04-01

    The effects of a pseudo-colour imaging method were investigated by discriminating among similar agricultural plots in remote sensing images acquired using the Airborne Visible/Infrared Imaging Spectrometer (Indiana, USA) and the Landsat 7 satellite (Fergana, Uzbekistan), and that provided by GoogleEarth (Toyama, Japan). From each dataset, red (R)-green (G)-R-G-blue yellow (RGrgbyB), and RGrgby-1B pseudo-colour images were prepared. From each, cyan, magenta, yellow, key black, L*, a*, and b* derivative grayscale images were generated. In the Airborne Visible/Infrared Imaging Spectrometer image, pixels were selected for corn no tillage (29 pixels), corn minimum tillage (27), and soybean (34) plots. Likewise, in the Landsat 7 image, pixels representing corn (73 pixels), cotton (110), and wheat (112) plots were selected, and in the GoogleEarth image, those representing soybean (118 pixels) and rice (151) were selected. When the 14 derivative grayscale images were used together with an RGB yellow grayscale image, the overall classification accuracy improved from 74 to 94% (Airborne Visible/Infrared Imaging Spectrometer), 64 to 83% (Landsat), or 77 to 90% (GoogleEarth). As an indicator of discriminatory power, the kappa significance improved 1018-fold (Airborne Visible/Infrared Imaging Spectrometer) or greater. The derivative grayscale images were found to increase the dimensionality and quantity of data. Herein, the details of the increases in dimensionality and quantity are further analysed and discussed.

  5. Pb isotopic composition, colour, and microstructure of monazites from a polymetamorphic rock in Antarctica

    NASA Astrophysics Data System (ADS)

    Black, Lance P.; Fitzgerald, John D.; Harley, Simon L.

    1984-02-01

    A moderate- to high-grade regionally metamorphosed paragneiss from Antarctica contains monazites of several different colours — brown, yellow and grey. Each colour type has a distinctive U-Pb isotopic composition which appears to result from different proportions of radiogenic Pb loss. Isotopic differences are neither related to La, Nd, Ce, P, Ca, Ti (and/or Ba), nor to U or Th content. All colour types have similar structures at the submicron scale, as determined by both conventional and high-resolution transmission electron microscopy (TEM). These show that the grains are essenttially non-metamict but are composed of 100 Å crystalline domains misoriented from each other by no more than 2× 10-3 radians, and separated by narrow confused boundary regions where misorientation is probably accommodated by imperfect atomic arrangements. These regions of mismatch form potential zones of high permeability/diffusivity which are believed to be fundamental to the isotopic and colour differences between grains. Colour type is apparently related to the capacity of different minerals to shield included monazite grains from fluids circulating in the rock system. The well aligned monazite U — Pb analyses produce concordia intercepts of 2429{-16/+17}Ma and 1087±29 Ma. Both ages are comparable to those of major geological events in this part of Antarctica. They are interpreted in terms of isotopic resetting through Pb loss, and original monazite crystallisation is thought to have occurred somewhat earlier, possibly at the time this terrain first underwent granulite-facies metamorphism, about 3070 Ma ago.

  6. 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.

  7. Quantitative phase imaging of human red blood cells using phase-shifting white light interference microscopy with colour fringe analysis

    NASA Astrophysics Data System (ADS)

    Singh Mehta, Dalip; Srivastava, Vishal

    2012-11-01

    We report quantitative phase imaging of human red blood cells (RBCs) using phase-shifting interference microscopy. Five phase-shifted white light interferograms are recorded using colour charge coupled device camera. White light interferograms were decomposed into red, green, and blue colour components. The phase-shifted interferograms of each colour were then processed by phase-shifting analysis and phase maps for red, green, and blue colours were reconstructed. Wavelength dependent refractive index profiles of RBCs were computed from the single set of white light interferogram. The present technique has great potential for non-invasive determination of refractive index variation and morphological features of cells and tissues.

  8. How bees discriminate a pattern of two colours from its mirror image.

    PubMed

    Horridge, Adrian

    2015-01-01

    A century ago, in his study of colour vision in the honeybee (Apis mellifera), Karl von Frisch showed that bees distinguish between a disc that is half yellow, half blue, and a mirror image of the same. Although his inference of colour vision in this example has been accepted, some discrepancies have prompted a new investigation of the detection of polarity in coloured patterns. In new experiments, bees restricted to their blue and green receptors by exclusion of ultraviolet could learn patterns of this type if they displayed a difference in green contrast between the two colours. Patterns with no green contrast required an additional vertical black line as a landmark. Tests of the trained bees revealed that they had learned two inputs; a measure and the retinotopic position of blue with large field tonic detectors, and the measure and position of a vertical edge or line with small-field phasic green detectors. The angle between these two was measured. This simple combination was detected wherever it occurred in many patterns, fitting the definition of an algorithm, which is defined as a method of processing data. As long as they excited blue receptors, colours could be any colour to human eyes, even white. The blue area cue could be separated from the green receptor modulation by as much as 50°. When some blue content was not available, the bees learned two measures of the modulation of the green receptors at widely separated vertical edges, and the angle between them. There was no evidence that the bees reconstructed the lay-out of the pattern or detected a tonic input to the green receptors.

  9. How Bees Discriminate a Pattern of Two Colours from Its Mirror Image

    PubMed Central

    Horridge, Adrian

    2015-01-01

    A century ago, in his study of colour vision in the honeybee (Apis mellifera), Karl von Frisch showed that bees distinguish between a disc that is half yellow, half blue, and a mirror image of the same. Although his inference of colour vision in this example has been accepted, some discrepancies have prompted a new investigation of the detection of polarity in coloured patterns. In new experiments, bees restricted to their blue and green receptors by exclusion of ultraviolet could learn patterns of this type if they displayed a difference in green contrast between the two colours. Patterns with no green contrast required an additional vertical black line as a landmark. Tests of the trained bees revealed that they had learned two inputs; a measure and the retinotopic position of blue with large field tonic detectors, and the measure and position of a vertical edge or line with small-field phasic green detectors. The angle between these two was measured. This simple combination was detected wherever it occurred in many patterns, fitting the definition of an algorithm, which is defined as a method of processing data. As long as they excited blue receptors, colours could be any colour to human eyes, even white. The blue area cue could be separated from the green receptor modulation by as much as 50°. When some blue content was not available, the bees learned two measures of the modulation of the green receptors at widely separated vertical edges, and the angle between them. There was no evidence that the bees reconstructed the lay-out of the pattern or detected a tonic input to the green receptors. PMID:25617892

  10. Digital image processing versus visual assessment of chewed two-colour wax in mixing ability tests.

    PubMed

    van der Bilt, A; Speksnijder, C M; de Liz Pocztaruk, R; Abbink, J H

    2012-01-01

    Two-colour chewing gum and wax have been widely used as test foods to evaluate the ability to mix and knead a food bolus. The mixing of the colours has been assessed by computer analysis or by visual inspection. Reports contradict each other about whether computer analysis and visual assessment could equally well discriminate between the masticatory performances of groups of participants with different dental status. This study compares the results of computer analysis of digital images of chewed two-colour wax with the results of visual assessment of these images. Sixty healthy subjects participated and chewed on red-blue wax for 5, 10, 15 and 20 chewing strokes. The subjects were divided into three groups of 20, matched for age and gender, according to their dental status: natural dentition, full dentures and maxillary denture plus implant-supported mandibular overdenture. Mixing of the chewed wax was determined by computer analysis of images of the wax and by visual assessment of the images by five examiners. Both the computer method and the observers were able to distinguish the mixing abilities of the dentate subjects from the two denture wearer groups. Computer analysis could also discriminate the mixing abilities of the two denture groups. However, observers were not able to distinguish the mixing abilities of the two denture groups after 5, 10 and 15 chewing strokes. Only after 20 chewing strokes, they could detect a significant difference in mixing ability.

  11. Minimally invasive use of coloured composite resin in aesthetic restoration of periodontially involved teeth: Case report.

    PubMed

    Wahbi, M A; Al Sharief, H S; Tayeb, H; Bokhari, A

    2013-04-01

    Gingival recession causes not only aesthetic problems, but problems with oral hygiene, plaque accumulation, speech, and tooth sensitivity. Replacing the missing gingival tissue with composite resin, when indicated, can be a time- and cost-effective solution. Here we report the case of a 25-year-old female who presented with generalized gingival recession. Black triangles were present between the maxillary and mandibular anterior teeth due to loss of interdental tissues, caused by recent periodontal surgery. She also had slightly malposed maxillary anterior teeth. The patient elected to replace gingival tissue with pink composite resin and to alter the midline with composite resin veneers. The first treatment phase involved placement of pink gingival composite to restore the appearance of interdental papilla to her upper (16, 15, 14, 13, 12, 11, 21, 22, 23, and 24) and lower (34, 33, 32, 31, 41, 42, 43, and 44) teeth. Phase two was to place direct composite resin bonded veneers on her upper (16, 15, 14, 13, 12, 11, 21, 22, 23, and 24) teeth to alter the midline and achieve desired colour. The third treatment phase was to level the lower incisal edge shape by enameloplasty (31, 32, 41, and 42) to produce a more youthful and attractive smile. This case report and brief review attempt to describe the clinical obstacles and the current treatment options along with a suggested protocol. Use of contemporary materials such as gingival coloured composite to restore lost gingival tissue and improve aesthetics can be a simple and cost-effective way to manage patients affected by generalized aggressive periodontitis (AgP).

  12. Minimally invasive use of coloured composite resin in aesthetic restoration of periodontially involved teeth: Case report

    PubMed Central

    Wahbi, M.A.; Al Sharief, H.S.; Tayeb, H.; Bokhari, A.

    2013-01-01

    Gingival recession causes not only aesthetic problems, but problems with oral hygiene, plaque accumulation, speech, and tooth sensitivity. Replacing the missing gingival tissue with composite resin, when indicated, can be a time- and cost-effective solution. Here we report the case of a 25-year-old female who presented with generalized gingival recession. Black triangles were present between the maxillary and mandibular anterior teeth due to loss of interdental tissues, caused by recent periodontal surgery. She also had slightly malposed maxillary anterior teeth. The patient elected to replace gingival tissue with pink composite resin and to alter the midline with composite resin veneers. The first treatment phase involved placement of pink gingival composite to restore the appearance of interdental papilla to her upper (16, 15, 14, 13, 12, 11, 21, 22, 23, and 24) and lower (34, 33, 32, 31, 41, 42, 43, and 44) teeth. Phase two was to place direct composite resin bonded veneers on her upper (16, 15, 14, 13, 12, 11, 21, 22, 23, and 24) teeth to alter the midline and achieve desired colour. The third treatment phase was to level the lower incisal edge shape by enameloplasty (31, 32, 41, and 42) to produce a more youthful and attractive smile. This case report and brief review attempt to describe the clinical obstacles and the current treatment options along with a suggested protocol. Use of contemporary materials such as gingival coloured composite to restore lost gingival tissue and improve aesthetics can be a simple and cost-effective way to manage patients affected by generalized aggressive periodontitis (AgP). PMID:23960560

  13. The colour preference control based on two-colour combinations

    NASA Astrophysics Data System (ADS)

    Hong, Ji Young; Kwak, Youngshin; Park, Du-Sik; Kim, Chang Yeong

    2008-02-01

    This paper proposes a framework of colour preference control to satisfy the consumer's colour related emotion. A colour harmony algorithm based on two-colour combinations is developed for displaying the images with several complementary colour pairs as the relationship of two-colour combination. The colours of pixels belonging to complementary colour areas in HSV colour space are shifted toward the target hue colours and there is no colour change for the other pixels. According to the developed technique, dynamic emotions by the proposed hue conversion can be improved and the controlled output image shows improved colour emotions in the preference of the human viewer. The psychophysical experiments are conducted to investigate the optimal model parameters to produce the most pleasant image to the users in the respect of colour emotions.

  14. Two-colour live-cell nanoscale imaging of intracellular targets

    PubMed Central

    Bottanelli, Francesca; Kromann, Emil B.; Allgeyer, Edward S.; Erdmann, Roman S.; Wood Baguley, Stephanie; Sirinakis, George; Schepartz, Alanna; Baddeley, David; Toomre, Derek K.; Rothman, James E.; Bewersdorf, Joerg

    2016-01-01

    Stimulated emission depletion (STED) nanoscopy allows observations of subcellular dynamics at the nanoscale. Applications have, however, been severely limited by the lack of a versatile STED-compatible two-colour labelling strategy for intracellular targets in living cells. Here we demonstrate a universal labelling method based on the organic, membrane-permeable dyes SiR and ATTO590 as Halo and SNAP substrates. SiR and ATTO590 constitute the first suitable dye pair for two-colour STED imaging in living cells below 50 nm resolution. We show applications with mitochondria, endoplasmic reticulum, plasma membrane and Golgi-localized proteins, and demonstrate continuous acquisition for up to 3 min at 2-s time resolution. PMID:26940217

  15. Two-colour live-cell nanoscale imaging of intracellular targets

    NASA Astrophysics Data System (ADS)

    Bottanelli, Francesca; Kromann, Emil B.; Allgeyer, Edward S.; Erdmann, Roman S.; Wood Baguley, Stephanie; Sirinakis, George; Schepartz, Alanna; Baddeley, David; Toomre, Derek K.; Rothman, James E.; Bewersdorf, Joerg

    2016-03-01

    Stimulated emission depletion (STED) nanoscopy allows observations of subcellular dynamics at the nanoscale. Applications have, however, been severely limited by the lack of a versatile STED-compatible two-colour labelling strategy for intracellular targets in living cells. Here we demonstrate a universal labelling method based on the organic, membrane-permeable dyes SiR and ATTO590 as Halo and SNAP substrates. SiR and ATTO590 constitute the first suitable dye pair for two-colour STED imaging in living cells below 50 nm resolution. We show applications with mitochondria, endoplasmic reticulum, plasma membrane and Golgi-localized proteins, and demonstrate continuous acquisition for up to 3 min at 2-s time resolution.

  16. UV durable colour pigment doped SmA liquid crystal composites for outdoor trans-reflective bi-stable displays

    NASA Astrophysics Data System (ADS)

    Xu, H.; Davey, A. B.; Crossland, W. A.; Chu, D. P.

    2012-10-01

    High brightness trans-reflective bi-stable displays based on smectic A (SmA) liquid crystals (LCs) can have nearly perfect transparency in the clear state and very high reflection in the scattered state. Because the LC material in use is stable under UV radiation, this kind of displays can stand for strong day-light and therefore be ideal for outdoor applications from e-books to public signage and advertisement. However, the colour application has been limited because the traditional colourants in use are conventional dyes which are lack of UV stability and that their colours are easily photo bleached. Here we present a colour SmA display demonstrator using pigments as colourant. Mixing pigments with SmA LCs and maintain the desirable optical switching performance is not straightforward. We show here how it can be done, including how to obtain fine sized pigment nano-particles, the effects of particle size and size distribution on the display performance. Our optimized pigments/SmA compositions can be driven by a low frequency waveform (~101Hz) to a scattered state to exhibit colour while by a high frequency waveform (~103Hz) to a cleared state showing no colour. Finally, we will present its excellent UV life-time (at least <7.2 years) in comparison with that of dye composition (~2.4 years). The complex interaction of pigment nano-particles with LC molecules and the resulting effects on the LC electro-optical performances are still to be fully understood. We hope this work will not only demonstrate a new and practical approach for outdoor reflective colour displays but also provide a new material system for fundamental liquid crystal colloid research work.

  17. ICL: The Image Composition Language

    NASA Technical Reports Server (NTRS)

    Foley, James D.; Kim, Won Chul

    1986-01-01

    The Image Composition Language (ICL) provides a convenient way for programmers of interactive graphics application programs to define how the video look-up table of a raster display system is to be loaded. The ICL allows one or several images stored in the frame buffer to be combined in a variety of ways. The ICL treats these images as variables, and provides arithematic, relational, and conditional operators to combine the images, scalar variables, and constants in image composition expressions. The objective of ICL is to provide programmers with a simple way to compose images, to relieve the tedium usually associated with loading the video look-up table to obtain desired results.

  18. Correction of motion artefacts and pseudo colour visualization of multispectral light scattering images for optical diagnosis of rheumatoid arthritis

    NASA Astrophysics Data System (ADS)

    Minet, Olaf; Scheibe, Patrick; Beuthan, Jürgen; Zabarylo, Urszula

    2010-02-01

    State-of-the-art image processing methods offer new possibilities for diagnosing diseases using scattered light. The optical diagnosis of rheumatism is taken as an example to show that the diagnostic sensitivity can be improved using overlapped pseudo-coloured images of different wavelengths, provided that multispectral images are recorded to compensate for any motion related artefacts which occur during examination.

  19. Correction of motion artefacts and pseudo colour visualization of multispectral light scattering images for optical diagnosis of rheumatoid arthritis

    NASA Astrophysics Data System (ADS)

    Minet, Olaf; Scheibe, Patrick; Beuthan, Jürgen; Zabarylo, Urszula

    2009-10-01

    State-of-the-art image processing methods offer new possibilities for diagnosing diseases using scattered light. The optical diagnosis of rheumatism is taken as an example to show that the diagnostic sensitivity can be improved using overlapped pseudo-coloured images of different wavelengths, provided that multispectral images are recorded to compensate for any motion related artefacts which occur during examination.

  20. Dual-colour imaging of RNAs using quencher- and fluorophore-binding aptamers.

    PubMed

    Arora, Ankita; Sunbul, Murat; Jäschke, Andres

    2015-12-01

    In order to gain deeper insight into the functions and dynamics of RNA in cells, the development of methods for imaging multiple RNAs simultaneously is of paramount importance. Here, we describe a modular approach to image RNA in living cells using an RNA aptamer that binds to dinitroaniline, an efficient general contact quencher. Dinitroaniline quenches the fluorescence of different fluorophores when directly conjugated to them via ethylene glycol linkers by forming a non-fluorescent intramolecular complex. Since the binding of the RNA aptamer to the quencher destroys the fluorophore-quencher complex, fluorescence increases dramatically upon binding. Using this principle, a series of fluorophores were turned into fluorescent turn-on probes by conjugating them to dinitroaniline. These probes ranged from fluorescein-dinitroaniline (green) to TexasRed-dinitroaniline (red) spanning across the visible spectrum. The dinitroaniline-binding aptamer (DNB) was generated by in vitro selection, and was found to bind all probes, leading to fluorescence increase in vitro and in living cells. When expressed in E. coli, the DNB aptamer could be labelled and visualized with different-coloured fluorophores and therefore it can be used as a genetically encoded tag to image target RNAs. Furthermore, combining contact-quenched fluorogenic probes with orthogonal DNB (the quencher-binding RNA aptamer) and SRB-2 aptamers (a fluorophore-binding RNA aptamer) allowed dual-colour imaging of two different fluorescence-enhancing RNA tags in living cells, opening new avenues for studying RNA co-localization and trafficking.

  1. The influence of the microscope lamp filament colour temperature on the process of digital images of histological slides acquisition standardization

    PubMed Central

    2014-01-01

    Background The aim of this study is to compare the digital images of the tissue biopsy captured with optical microscope using bright field technique under various light conditions. The range of colour's variation in immunohistochemically stained with 3,3'-Diaminobenzidine and Haematoxylin tissue samples is immense and coming from various sources. One of them is inadequate setting of camera's white balance to microscope's light colour temperature. Although this type of error can be easily handled during the stage of image acquisition, it can be eliminated with use of colour adjustment algorithms. The examination of the dependence of colour variation from microscope's light temperature and settings of the camera is done as an introductory research to the process of automatic colour standardization. Methods Six fields of view with empty space among the tissue samples have been selected for analysis. Each field of view has been acquired 225 times with various microscope light temperature and camera white balance settings. The fourteen randomly chosen images have been corrected and compared, with the reference image, by the following methods: Mean Square Error, Structural SIMilarity and visual assessment of viewer. Results For two types of backgrounds and two types of objects, the statistical image descriptors: range, median, mean and its standard deviation of chromaticity on a and b channels from CIELab colour space, and luminance L, and local colour variability for objects' specific area have been calculated. The results have been averaged for 6 images acquired in the same light conditions and camera settings for each sample. Conclusions The analysis of the results leads to the following conclusions: (1) the images collected with white balance setting adjusted to light colour temperature clusters in certain area of chromatic space, (2) the process of white balance correction for images collected with white balance camera settings not matched to the light temperature

  2. Spatially coherent colour image reconstruction from a trichromatic mosaic with random arrangement of chromatic samples.

    PubMed

    Alleysson, David

    2010-09-01

    Recent high resolution imaging of the human retina confirms that the trichromatic cone mosaic follows a random arrangement. Moreover, both the cones' arrangements and proportion widely differ from individual to individual. These findings provide new insights to our understanding of colour vision as most of the previous vision models ignored the mosaic sampling. Here, we propose a cone mosaic sampling simulation applied to colour images. From the simulation, we can infer the processing needs for retrieving spatial and chromatic information from the mosaic without spatial ambiguity. In particular, the focus is on the ability of the visual system to reconstruct coherent spatial information from a plurality of local neighbourhoods. We show that normalized linear processing allows the recovery of achromatic and chromatic information from a mosaic of trichromatic samples arranged randomly. Also, low frequency components of achromatic information can serve to coarsely estimate orientation, which in turn improves the interpolation of chromatic information. An implication for the visual system is the possibility that, in the cortex, the low frequency achromatic spatial information of the magnocellular pathway helps separate chromatic information from the mixed achromatic/chromatic information carried by the parvocellular pathway. PMID:20883332

  3. Colour of fat, and colour, fatty acid composition and sensory characteristics of muscle from heifers offered alternative forages to grass silage in a finishing ration.

    PubMed

    Moloney, A P; Mooney, M T; Kerry, J P; Stanton, C; O'Kiely, P

    2013-11-01

    The effect of type of silage offered to beef heifers during the finishing period on aspects of beef quality was determined. In two experiments, a diet based on grass silage (GS) was compared with a diet based on maize silage (MS) or whole-crop wheat silage (WCW). Compared to the GS-based diet, increasing the amount of MS linearly increased fat whiteness while the increase in fat whiteness due to WCW was dependent on the stage of crop maturity at harvesting. There was no effect of diet on muscle colour or on muscle pH measured at 48h post-mortem, drip loss, taste panel traits after 14days ageing or shear force values at 2, 7 or 14days ageing. The alternative silages decreased the n-3 polyunsaturated fatty acid proportion and increased the linoleic:linolenic acid ratio in intramuscular lipid. It is concluded that type of silage affects fat colour and fatty acid composition of muscle but not the other muscle characteristics examined.

  4. Validation of a neuro-variational inversion of ocean colour images

    NASA Astrophysics Data System (ADS)

    Brajard, J.; Jamet, C.; Moulin, C.; Thiria, S.

    2006-01-01

    Ocean colour sensors on board satellite measure the solar radiation reflected by the ocean and the atmosphere. This information, denoted reflectance, is affected for about 90% by air molecules and aerosols in the atmosphere and only for about 10% by water molecules and phytoplankton cells in the ocean. Our method focuses on the chlorophyll- a concentration (chl- a) retrieval, which is commonly used as a proxy for phytoplankton concentration. Our algorithm, denoted NeuroVaria, computes relevant atmospheric (Angström coefficient, optical thickness, single-scattering albedo) and oceanic parameters (chl- a, oceanic particulate scattering) by minimizing the difference over the whole spectrum (visible + near-infrared) between the observed reflectance and the reflectance computed from artificial neural networks that have been trained with a radiative transfer model. This algorithm has been presented in [Jamet, C., Thiria, S., Moulin, C., Crepon, M. Use of a neuro-variational inversion for retrieving oceanic and atmospheric constituents from ocean colour imagery. a feasibility study. J. Atmo. Ocean. Tech. 22 (4), 460-475, doi: 10.1175/JTECH1688.1, 2005]. NeuroVaria has been applied to SeaWiFS imagery in the Mediterranean sea. A comparison in the Mediterranean with in-situ measurements of the water-leaving reflectance, optical thickness and chl- a shows that NeuroVaria is consistent to process accurate atmospheric corrections and chl- a estimation for case-I waters and weakly absorbing aerosols. It validates the first step of this new approach of ocean colour images processing.

  5. Practical colour management

    NASA Astrophysics Data System (ADS)

    Williams, Susan

    2006-06-01

    Spectrophotometers have been successfully used for colour measurement. This paper addresses digital imaging as a complementary and alternative method of colour measurement and appearance and an effective communication tool as part of a practical colour management programme within the supply chain of a textile retailer. The specific needs—to measure and communicate textured dyed material and printed fabric—are discussed, as well as the colour specification and quality control (QC) of currently un-measurable fabrics and accessories. A unique method of using digital imaging for the assessment of colour fastness will also be discussed.

  6. Colour and pigment composition of red wines obtained from co-maceration of Tempranillo and Graciano varieties.

    PubMed

    García-Marino, Matilde; Hernández-Hierro, José Miguel; Rivas-Gonzalo, Julián C; Escribano-Bailón, M Teresa

    2010-02-15

    The Vitis vinifera L. cv Graciano is often used as an integral component of Rioja wines because it is considered to contribute significantly to the quality of Tempranillo based wines. The aim of this work was to determine the effect of the incorporation of the Graciano variety on the colour and pigment composition of Tempranillo based wine and to evaluate the possible differences between blending Tempranillo with Graciano varietal wine (W wine) in contrast to a wine obtained by mixing these two grape varieties in the prefermentative maceration step (M wine). Results indicated that pigment extraction and retention in M wine was higher than in Tempranillo (T) wine. Colour differences (DeltaE(ab)(*)) between wines at the end of the study (after 12 months in bottles) were detectable by the human eye (DeltaE(ab)(*) > or = 3) in all cases except for T and W. These wines have indistinguishable colours even when using analytical methods (DeltaE(ab)(*) < or = 1). Regarding hue h(ab), T and W presented higher values (more orange-red) than Graciano (G) and M (more blue-red). PCA allowed the colour and composition analytical data to be reduced to a small number of principal components that could separate successfully between T and G wines and between the different steps of the winemaking process.

  7. Digital enhancement of haematoxylin- and eosin-stained histological images for red-green colour-blind observers.

    PubMed

    Landini, G; Perryer, G

    2009-06-01

    Individuals with red-green colour-blindness (CB) commonly experience great difficulty differentiating between certain histological stain pairs, notably haematoxylin-eosin (H&E). The prevalence of red-green CB is high (6-10% of males), including among medical and laboratory personnel, and raises two major concerns: first, accessibility and equity issues during the education and training of individuals with this disability, and second, the likelihood of errors in critical tasks such as interpreting histological images. Here we show two methods to enhance images of H&E-stained samples so the differently stained tissues can be well discriminated by red-green CBs while remaining usable by people with normal vision. Method 1 involves rotating and stretching the range of H&E hues in the image to span the perceptual range of the CB observers. Method 2 digitally unmixes the original dyes using colour deconvolution into two separate images and repositions the information into hues that are more distinctly perceived. The benefits of these methods were tested in 36 volunteers with normal vision and 11 with red-green CB using a variety of H&E stained tissue sections paired with their enhanced versions. CB subjects reported they could better perceive the different stains using the enhanced images for 85% of preparations (method 1: 90%, method 2: 73%), compared to the H&E-stained original images. Many subjects with normal vision also preferred the enhanced images to the original H&E. The results suggest that these colour manipulations confer considerable advantage for those with red-green colour vision deficiency while not disadvantaging people with normal colour vision.

  8. The Colour and Stereo Surface Imaging System for ESA's Trace Gas Orbiter

    NASA Astrophysics Data System (ADS)

    Thomas, Nicolas; Cremonese, Gabriele

    2016-04-01

    The Colour and Stereo Surface Imaging System (CaSSIS) is an 11 μrad/px imaging system ready to launch on the European Space Agency's (ESA) ExoMars Trace Gas Orbiter (TGO) on 14 March 2016 from Baikonur. CaSSIS is based around an 880 mm focal length carbon-fibre reinforced polymer (CFRP) telescope with a 135 mm primary mirror and a 2k x 2k CMOS hybrid detector with 10 micron pixel pitch providing 4.6 m/px imaging from the nominal 400 km circular orbit. The telescope is a slightly modified three mirror anastigmat optical configuration with no central obscuration. The instrument is designed to operate in "push-frame" mode where 2048 x 256 images are acquired at a repetition rate which matches the ground-track velocity (~3 km/s) allowing sufficient overlap for co-registration thereby building image strips along the surface. A filter strip assembly (FSA) is mounted directly above the detector providing images in 4 wavelength bands. Two of these (480.5nm and 676.5nm prior to convolution with the rest of the instrument) correspond closely to bands used by the HiRISE instrument on the Mars Reconnaissance Orbiter [4]. Two other filters split the NIR wavelengths with centres at 838 nm and close to 985 nm. Analyses show that the filters provide good differentiation between expected surface minerals, particularly Fe-bearing phases (Tornabene et al. LPSC, 2016). CaSSIS is designed to produce stereo from images acquired ~30 s apart by using a rotation drive. The telescope points 10 degrees off-nadir. The drive aligns the telescope with the ground-track direction so that the telescope is pointing forward. After image acquisition, the telescope is rapidly rotated by 180 degrees to point in the opposite direction and the second image of the stereo pair is acquired. CaSSIS will extend the monitoring of past missions to future years allowing the tracking of longer-term changes. It will also provide contemporaneous imaging of regions that may produce unique signatures detected by

  9. Colour matching of composite resin cements with their corresponding try-in pastes.

    PubMed

    Kampouropoulos, D; Gaintantzopoulou, M; Papazoglou, E; Kakaboura, A

    2014-06-01

    Two shades of four resin cements (Calibra, Clearfil Esthetic, Insure, Variolink II), in light- and dual-curing modes, were tested for colour matching with their corresponding try-in pastes, immediately after photopolymerization and after 24-hour dry and dark storage. Colour measurements were performed for 0.8 mm-thick specimens through a 0.8mm-thick ceramic plate. For each resin cement, colour differences (deltaE) were calculated between the two curing modes, and between the corresponding try-in paste, at baseline and after 24h. deltaE>0 values were detected between all resin cements and their try-in pastes, which were brand/shade/curing mode depended. The try-in pastes of the Variolink II system demonstrated the best colour matching (deltaE<2). Try-in pastes of Calibra and Insure, at both curing modes, did not match at an acceptable value, the shade of their corresponding resin cements (deltaE>3.3). Calibra presented the highest colour differences. deltaE values of the Clearfil Esthetic system immediately after photo-activation ranged between 2 and 3 units. A ceramic restoration may fail aesthetically as a result of not acceptable colour match (deltaE>3.3) between the shade of certain resin cements and their relevant try-in pastes. PMID:25134367

  10. Colour matching of composite resin cements with their corresponding try-in pastes.

    PubMed

    Kampouropoulos, D; Gaintantzopoulou, M; Papazoglou, E; Kakaboura, A

    2014-06-01

    Two shades of four resin cements (Calibra, Clearfil Esthetic, Insure, Variolink II), in light- and dual-curing modes, were tested for colour matching with their corresponding try-in pastes, immediately after photopolymerization and after 24-hour dry and dark storage. Colour measurements were performed for 0.8 mm-thick specimens through a 0.8mm-thick ceramic plate. For each resin cement, colour differences (deltaE) were calculated between the two curing modes, and between the corresponding try-in paste, at baseline and after 24h. deltaE>0 values were detected between all resin cements and their try-in pastes, which were brand/shade/curing mode depended. The try-in pastes of the Variolink II system demonstrated the best colour matching (deltaE<2). Try-in pastes of Calibra and Insure, at both curing modes, did not match at an acceptable value, the shade of their corresponding resin cements (deltaE>3.3). Calibra presented the highest colour differences. deltaE values of the Clearfil Esthetic system immediately after photo-activation ranged between 2 and 3 units. A ceramic restoration may fail aesthetically as a result of not acceptable colour match (deltaE>3.3) between the shade of certain resin cements and their relevant try-in pastes.

  11. 3D colour visualization of label images using volume rendering techniques.

    PubMed

    Vandenhouten, R; Kottenhoff, R; Grebe, R

    1995-01-01

    Volume rendering methods for the visualization of 3D image data sets have been developed and collected in a C library. The core algorithm consists of a perspective ray casting technique for a natural and realistic view of the 3D scene. New edge operator shading methods are employed for a fast and information preserving representation of surfaces. Control parameters of the algorithm can be tuned to have either smoothed surfaces or a very detailed rendering of the geometrical structure. Different objects can be distinguished by different colours. Shadow ray tracing has been implemented to improve the realistic impression of the 3D image. For a simultaneous representation of objects in different depths, hiding each other, two types of transparency mode are used (wireframe and glass transparency). Single objects or groups of objects can be excluded from the rendering (peeling). Three orthogonal cutting planes or one arbitrarily placed cutting plane can be applied to the rendered objects in order to get additional information about inner structures, contours, and relative positions.

  12. Image Composition Engine for Tiles

    2011-08-22

    The Image Composition Engine for Tiles (lceT) is a high-performance sort-last parallel rendering library. It is designed to be used in parallel applications requiring rendering. The primary purpose of IceT is to be integrated into parallel visualization applications such as ParaView to provide parallel rendering capabilities. The Image Composition Engine for Tiles (lceT) is a high-performance sort-last parallel rendering library. IceT uses a "sort-Iasf' approach to rendering. Each process in a parallel application independently rendersmore » a local piece of geometry. The resulting images are given to IceT, and IceT combines the images together to form a single cohesive image. Ice T is also capable of driving tiled displays, largeformat displays comprising an array of smaller displays. To this end IceT can collect the smaller tile images and organize them such that the entire tiled display can be driven. Ice T takes advantage of spatial coherence in geometry by identifying empty regions of the display and reducing the overall required work.« less

  13. Image Composition Engine for Tiles

    SciTech Connect

    Moreland, Kenneth

    2011-08-22

    The Image Composition Engine for Tiles (lceT) is a high-performance sort-last parallel rendering library. It is designed to be used in parallel applications requiring rendering. The primary purpose of IceT is to be integrated into parallel visualization applications such as ParaView to provide parallel rendering capabilities. The Image Composition Engine for Tiles (lceT) is a high-performance sort-last parallel rendering library. IceT uses a "sort-Iasf' approach to rendering. Each process in a parallel application independently renders a local piece of geometry. The resulting images are given to IceT, and IceT combines the images together to form a single cohesive image. Ice T is also capable of driving tiled displays, largeformat displays comprising an array of smaller displays. To this end IceT can collect the smaller tile images and organize them such that the entire tiled display can be driven. Ice T takes advantage of spatial coherence in geometry by identifying empty regions of the display and reducing the overall required work.

  14. Is colour cognitive?

    NASA Astrophysics Data System (ADS)

    Skorupski, Peter; Chittka, Lars

    2011-03-01

    In recent years, colour-vision abilities have been rather generously ascribed to various invertebrates and even bacteria. This uncertainty of when to diagnose colour vision stems in part from confusing what colour vision can do with what it is. What colour vision can do is discriminate wavelength independent of intensity. However, if we take this as a definition of what colour vision is, then we might be obliged to conclude that some plants and bacteria have colour vision. Moreover, there is a similar confusion of what are necessary and what are sufficient mechanisms and behavioural abilities for colour vision. To humans, seeing in colour means seeing an image in which objects/lights have chromatic attributes—in contrast to the sensation that we have when viewing monochrome movies, or our experience in dim light when only rod vision is possible. The necessary basic equipment for this is to have at least two types of photoreceptors that differ in spectral sensitivity, and at least one type of spectrally opponent cell to compare the signals from the photoreceptors. Clearly, however, a necessary additional prerequisite for colour vision is to have vision, which entails the identification of shapes, sizes and locations of objects in the world. Thus, if an animal has colour vision, it should see an image in which distinct objects/lights have colour attributes. This distinguishes colour vision from wavelength discrimination, but also from what has historically been called wavelength-specific behaviour: a type of behaviour triggered by fixed configurations of spectral receptor signals; however, we discuss difficulties in diagnosing wavelength-specific behaviour as an indicator of the absence of colour vision. Finally, we discuss whether colour vision, by definition, contains a cognitive dimension for ordering and classifying perceptual experience.

  15. Colour constancy in insects.

    PubMed

    Chittka, Lars; Faruq, Samia; Skorupski, Peter; Werner, Annette

    2014-06-01

    Colour constancy is the perceptual phenomenon that the colour of an object appears largely unchanged, even if the spectral composition of the illuminating light changes. Colour constancy has been found in all insect species so far tested. Especially the pollinating insects offer a remarkable opportunity to study the ecological significance of colour constancy since they spend much of their adult lives identifying and choosing between colour targets (flowers) under continuously changing ambient lighting conditions. In bees, whose colour vision is best studied among the insects, the compensation provided by colour constancy is only partial and its efficiency depends on the area of colour space. There is no evidence for complete 'discounting' of the illuminant in bees, and the spectral composition of the light can itself be used as adaptive information. In patchy illumination, bees adjust their spatial foraging to minimise transitions between variously illuminated zones. Modelling allows the quantification of the adaptive benefits of various colour constancy mechanisms in the economy of nature. We also discuss the neural mechanisms and cognitive operations that might underpin colour constancy in insects.

  16. A Comparative Study on Diagnostic Accuracy of Colour Coded Digital Images, Direct Digital Images and Conventional Radiographs for Periapical Lesions – An In Vitro Study

    PubMed Central

    Mubeen; K.R., Vijayalakshmi; Bhuyan, Sanat Kumar; Panigrahi, Rajat G; Priyadarshini, Smita R; Misra, Satyaranjan; Singh, Chandravir

    2014-01-01

    Objectives: The identification and radiographic interpretation of periapical bone lesions is important for accurate diagnosis and treatment. The present study was undertaken to study the feasibility and diagnostic accuracy of colour coded digital radiographs in terms of presence and size of lesion and to compare the diagnostic accuracy of colour coded digital images with direct digital images and conventional radiographs for assessing periapical lesions. Materials and Methods: Sixty human dry cadaver hemimandibles were obtained and periapical lesions were created in first and second premolar teeth at the junction of cancellous and cortical bone using a micromotor handpiece and carbide burs of sizes 2, 4 and 6. After each successive use of round burs, a conventional, RVG and colour coded image was taken for each specimen. All the images were evaluated by three observers. The diagnostic accuracy for each bur and image mode was calculated statistically. Results: Our results showed good interobserver (kappa > 0.61) agreement for the different radiographic techniques and for the different bur sizes. Conventional Radiography outperformed Digital Radiography in diagnosing periapical lesions made with Size two bur. Both were equally diagnostic for lesions made with larger bur sizes. Colour coding method was least accurate among all the techniques. Conclusion: Conventional radiography traditionally forms the backbone in the diagnosis, treatment planning and follow-up of periapical lesions. Direct digital imaging is an efficient technique, in diagnostic sense. Colour coding of digital radiography was feasible but less accurate however, this imaging technique, like any other, needs to be studied continuously with the emphasis on safety of patients and diagnostic quality of images. PMID:25584318

  17. Influence of choice of yeasts on volatile fermentation-derived compounds, colour and phenolics composition in Cabernet Sauvignon wine.

    PubMed

    Blazquez Rojas, Inmaculada; Smith, Paul A; Bartowsky, Eveline J

    2012-12-01

    Wine colour, phenolics and volatile fermentation-derived composition are the quintessential elements of a red wine. Many viticultural and winemaking factors contribute to wine aroma and colour with choice of yeast strain being a crucial factor. Besides the traditional Saccharomyces species S. cerevisiae, S. bayanus and several Saccharomyces interspecific hybrids are able to ferment grape juice to completion. This study examined the diversity in chemical composition, including phenolics and fermentation-derived volatile compounds, of an Australian Cabernet Sauvignon due to the use of different Saccharomyces strains. Eleven commercially available Saccharomyces strains were used in this study; S. cerevisiae (7), S. bayanus (2) and interspecific Saccharomyces hybrids (2). The eleven Cabernet Sauvignon wines varied greatly in their chemical composition. Nine yeast strains completed alcoholic fermentation in 19 days; S. bayanus AWRI 1375 in 26 days, and S. cerevisiae AWRI 1554 required 32 days. Ethanol concentrations varied in the final wines (12.7-14.2 %). The two S. bayanus strains produced the most distinct wines, with the ability to metabolise malic acid, generate high glycerol concentrations and distinctive phenolic composition. Saccharomyces hybrid AWRI 1501 and S. cerevisiae AWRI 1554 and AWRI 1493 also generated distinctive wines. This work demonstrates that the style of a Cabernet Sauvignon can be clearly modulated by choice of commercially available wine yeast. PMID:22878903

  18. Classification of pre-sliced pork and Turkey ham qualities based on image colour and textural features and their relationships with consumer responses.

    PubMed

    Iqbal, Abdullah; Valous, Nektarios A; Mendoza, Fernando; Sun, Da-Wen; Allen, Paul

    2010-03-01

    Images of three qualities of pre-sliced pork and Turkey hams were evaluated for colour and textural features to characterize and classify them, and to model the ham appearance grading and preference responses of a group of consumers. A total of 26 colour features and 40 textural features were extracted for analysis. Using Mahalanobis distance and feature inter-correlation analyses, two best colour [mean of S (saturation in HSV colour space), std. deviation of b*, which indicates blue to yellow in L*a*b* colour space] and three textural features [entropy of b*, contrast of H (hue of HSV colour space), entropy of R (red of RGB colour space)] for pork, and three colour (mean of R, mean of H, std. deviation of a*, which indicates green to red in L*a*b* colour space) and two textural features [contrast of B, contrast of L* (luminance or lightness in L*a*b* colour space)] for Turkey hams were selected as features with the highest discriminant power. High classification performances were reached for both types of hams (>99.5% for pork and >90.5% for Turkey) using the best selected features or combinations of them. In spite of the poor/fair agreement among ham consumers as determined by Kappa analysis (Kappa-value<0.4) for sensory grading (surface colour, colour uniformity, bitonality, texture appearance and acceptability), a dichotomous logistic regression model using the best image features was able to explain the variability of consumers' responses for all sensorial attributes with accuracies higher than 74.1% for pork hams and 83.3% for Turkey hams.

  19. Storage at low temperature differentially affects the colour and carotenoid composition of two cultivars of banana.

    PubMed

    Facundo, Heliofabia Virginia De Vasconcelos; Gurak, Poliana Deyse; Mercadante, Adriana Zerlotti; Lajolo, Franco Maria; Cordenunsi, Beatriz Rosana

    2015-03-01

    Different storage conditions can induce changes in the colour and carotenoid profiles and levels in some fruits. The goal of this work was to evaluate the influence of low temperature storage on the colour and carotenoid synthesis in two banana cultivars: Prata and Nanicão. For this purpose, the carotenoids from the banana pulp were determined by HPLC-DAD-MS/MS, and the colour of the banana skin was determined by a colorimeter method. Ten carotenoids were identified, of which the major carotenoids were all-trans-lutein, all-trans-α-carotene and all-trans-β-carotene in both cultivars. The effect of the low temperatures was subjected to linear regression analysis. In cv. Prata, all-trans-α-carotene and all-trans-β-carotene were significantly affected by low temperature (p<0.01), with negative estimated values (β coefficients) indicating that during cold storage conditions, the concentrations of these carotenoids tended to decrease. In cv. Nanicão, no carotenoid was significantly affected by cold storage (p>0.05). The accumulation of carotenoids in this group may be because the metabolic pathways using these carotenoids were affected by storage at low temperatures. The colour of the fruits was not negatively affected by the low temperatures (p>0.05).

  20. A feed-forward Hopfield neural network algorithm (FHNNA) with a colour satellite image for water quality mapping

    NASA Astrophysics Data System (ADS)

    Asal Kzar, Ahmed; Mat Jafri, M. Z.; Hwee San, Lim; Al-Zuky, Ali A.; Mutter, Kussay N.; Hassan Al-Saleh, Anwar

    2016-06-01

    There are many techniques that have been given for water quality problem, but the remote sensing techniques have proven their success, especially when the artificial neural networks are used as mathematical models with these techniques. Hopfield neural network is one type of artificial neural networks which is common, fast, simple, and efficient, but it when it deals with images that have more than two colours such as remote sensing images. This work has attempted to solve this problem via modifying the network that deals with colour remote sensing images for water quality mapping. A Feed-forward Hopfield Neural Network Algorithm (FHNNA) was modified and used with a satellite colour image from type of Thailand earth observation system (THEOS) for TSS mapping in the Penang strait, Malaysia, through the classification of TSS concentrations. The new algorithm is based essentially on three modifications: using HNN as feed-forward network, considering the weights of bitplanes, and non-self-architecture or zero diagonal of weight matrix, in addition, it depends on a validation data. The achieved map was colour-coded for visual interpretation. The efficiency of the new algorithm has found out by the higher correlation coefficient (R=0.979) and the lower root mean square error (RMSE=4.301) between the validation data that were divided into two groups. One used for the algorithm and the other used for validating the results. The comparison was with the minimum distance classifier. Therefore, TSS mapping of polluted water in Penang strait, Malaysia, can be performed using FHNNA with remote sensing technique (THEOS). It is a new and useful application of HNN, so it is a new model with remote sensing techniques for water quality mapping which is considered important environmental problem.

  1. Multi-coloured stereograms unveil two binocular colour mechanisms in human vision.

    PubMed

    Erkelens, Casper J; van Ee, Raymond

    2002-04-01

    Two different colours, one presented to one eye and the other presented to the other eye, often create the impression of a third colour. This percept is known as binocular colour mixture. Here we use coloured stereograms to study binocular colour appearance. Vivid pastel colours are induced in monocular, achromatic patches, if these are placed in stereograms whose left and right images differ in colour. The build-up of the colours is slow and takes tens of seconds or even minutes in certain individuals. The induced colours remain visible during monocular viewing of the patch and decay gradually. The same colours are induced irrespective of whether the patches are placed in fusible or rivalrous stereograms. We show that these colour effects cannot be induced by monocular colour mechanisms, either alone or in combination with binocular colour mixing. We suggest that the colours are induced by a binocular feedback mechanism, which reduces colour differences between the colour appearances of two monocular images. Induced colours are not observed if the achromatic patches are binocular. However, induced colours are apparent if one switches to monocular viewing after prolonged binocular viewing of the binocular patches. This aftereffect suggests that binocular colour induction acts on the monocular representations of binocular images. We suggest that during binocular viewing the fast process of binocular colour mixing masks the changes in colour appearance produced by the much slower process of binocular colour induction.

  2. False-colour palette generation using a reference colour gamut

    NASA Astrophysics Data System (ADS)

    Green, Phil

    2015-01-01

    Monochrome images are often converted to false-colour images, in which arbitrary colours are assigned to regions of the image to aid recognition of features within the image. Criteria for selection of colour palettes vary according to the application, but may include distinctiveness, extensibility, consistency, preference, meaningfulness and universality. A method for defining a palette from colours on the surface of a reference gamut is described, which ensures that all colours in the palette have the maximum chroma available for the given hue angle in the reference gamut. The palette can be re-targeted to a reproduction medium as needed using colour management, and this method ensures consistency between cross-media colour reproductions using the palette.

  3. The Colour and Stereo Surface Imaging System (CaSSIS) on ExoMars Trace Gas Orbiter (TGO): Building on orbital imaging from MRO and Mars Express

    NASA Astrophysics Data System (ADS)

    McEwen, A. S.; Thomas, N.; Cremonese, G.; Banaszkiewicz, M.; Bridges, J.; Byrne, S.; Da Deppo, V.; Debei, S.; El Maarry, M. R.; Hauber, E.; Hansen, C. J.; Ivanov, A.; Keszthelyi, L. P.; Kirk, R. L.; Kuzmin, R. O.; Mangold, N.; Marinangeli, L.; Markiewicz, W.; Massironi, M.; Okubo, C. H.; Orleanski, P.; Pommerol, A.; Tornabene, L. L.; Wajer, P.; Wray, J. J.

    2015-12-01

    TGO launch is expected in early 2016. Why do we need more orbital imaging of Mars given the near-global coverage by the High Resolution Stereo Camera (HRSC) on Mars Express and the Context Camera (CTX) on Mars Reconnaissance Orbiter (MRO), plus the very high-resolution coverage by MRO's High Resolution Imaging Science Experiment (HiRISE)? CaSSIS extends the monitoring of past missions to future years to track longer-term changes, and provides contemporaneous imaging of regions that may have unique signatures such as trace gases detected by other experiments on TGO. CaSSIS will provide the highest resolution (~4.6 m/pixel) coverage of Mars everywhere except the ~2% of Mars' surface covered by HiRISE (and only ~0.5% in colour or stereo) and another few percent covered by the Mars Orbital Camera (MOC). Although CTX has a similar imaging scale (~5.5 m/pixel), it does not provide colour images and useful stereo coverage is ~10% of Mars; CaSSIS uses a rotation mechanism to acquire along-track stereo with matching illumination of the surface. HRSC has provided >90% global stereo and colour coverage, but the highly elliptical orbit and wide-angle optics result in >10 m/pixel scale. Also, the HRSC images are acquired at different emission and phase angles per colour. The 72 degree inclined orbit of TGO means that it rotates through all local times of day several times per Mars season, so CaSSIS will have the unique ability to monitor how surfaces change with time of day as well as season, which could prove important to understanding recurring slope lineae (RSL) and frost distributions. This orbit also provides more opportunities to monitor the middle latitudes, for example to find new impacts that expose shallow clean ice. The 4 CaSSIS colour bands include matches to the 3 HiRISE colour bands, to extend monitoring of key sites. In summary, CaSSIS is by design complementary to past/continuing orbital imaging experiments.

  4. Detection of Hard Exudates in Colour Fundus Images Using Fuzzy Support Vector Machine-Based Expert System.

    PubMed

    Jaya, T; Dheeba, J; Singh, N Albert

    2015-12-01

    Diabetic retinopathy is a major cause of vision loss in diabetic patients. Currently, there is a need for making decisions using intelligent computer algorithms when screening a large volume of data. This paper presents an expert decision-making system designed using a fuzzy support vector machine (FSVM) classifier to detect hard exudates in fundus images. The optic discs in the colour fundus images are segmented to avoid false alarms using morphological operations and based on circular Hough transform. To discriminate between the exudates and the non-exudates pixels, colour and texture features are extracted from the images. These features are given as input to the FSVM classifier. The classifier analysed 200 retinal images collected from diabetic retinopathy screening programmes. The tests made on the retinal images show that the proposed detection system has better discriminating power than the conventional support vector machine. With the best combination of FSVM and features sets, the area under the receiver operating characteristic curve reached 0.9606, which corresponds to a sensitivity of 94.1% with a specificity of 90.0%. The results suggest that detecting hard exudates using FSVM contribute to computer-assisted detection of diabetic retinopathy and as a decision support system for ophthalmologists.

  5. Composite ultrasound imaging apparatus and method

    DOEpatents

    Morimoto, Alan K.; Bow, Jr., Wallace J.; Strong, David Scott; Dickey, Fred M.

    1998-01-01

    An imaging apparatus and method for use in presenting composite two dimensional and three dimensional images from individual ultrasonic frames. A cross-sectional reconstruction is applied by using digital ultrasound frames, transducer orientation and a known center. Motion compensation, rank value filtering, noise suppression and tissue classification are utilized to optimize the composite image.

  6. Composite ultrasound imaging apparatus and method

    DOEpatents

    Morimoto, A.K.; Bow, W.J. Jr.; Strong, D.S.; Dickey, F.M.

    1998-09-15

    An imaging apparatus and method for use in presenting composite two dimensional and three dimensional images from individual ultrasonic frames. A cross-sectional reconstruction is applied by using digital ultrasound frames, transducer orientation and a known center. Motion compensation, rank value filtering, noise suppression and tissue classification are utilized to optimize the composite image. 37 figs.

  7. Genetic investigations on Silybum marianum and S. eburneum with respect to leaf colour, outcrossing ratio, and flavonolignan composition.

    PubMed

    Hetz, E; Liersch, R; Schieder, O

    1995-02-01

    In crossing experiments between S. marianum and S. eburneum the number of fruits produced was relatively high as compared to the two parental species. All the F(1)-plants showed the variegated leaf characteristic of S. marianum, whereas after selfing the F(2)-plants had completely green and variegated leaves in a ratio of about 3:1 indicating that the leaf colour is monofactorially inherited. This proves that the two species are only variants. Using leaf colour as the genetic marker, the outcrossing rate in field experiments was studied. Since the outcrossing rate on average is only about 2%, SILYBUM is predominantly a self-pollinator. From 11 randomly selected plants, three inbred generations were produced and their silymarin composition (silibinin, silidianin, silichristin) was studied. Two types of lines could be distinguished based on the relative values of three flavonolignans: lines with approximately 70% silibinin, 30% silichristin, and traces of silidianin in all inbred generations and those with the relative contents of the compounds 30%, 57%, and 13%, respectively.

  8. Paper Colouration

    NASA Astrophysics Data System (ADS)

    McLow, Barry

    Of all the products added to paper, colour is often seen as the least important as, generally speaking, it adds nothing to the final properties of the paper. However, incorrect use of colour can turn paper, which would meet all the physical properties required of it, into paper which is unsuitable for sale, purely and simply because it is the wrong colour or shade. Correct use of colour, therefore, is of utmost importance to the papermaker.

  9. Enhancement of the resolution of full-field optical coherence tomography by using a colour image sensor

    SciTech Connect

    Kalyanov, A L; Lychagov, V V; Smirnov, I V; Ryabukho, V P

    2013-08-31

    The influence of white balance in a colour image detector on the resolution of a full-field optical coherence tomograph (FFOCT) is studied. The change in the interference pulse width depending on the white balance tuning is estimated in the cases of a thermal radiation source (incandescent lamp) and a white light emitting diode. It is shown that by tuning white balance of the detector in a certain range, the FFOCT resolution can be increased by 20 % as compared to the resolution, attained with the use of a monochrome detector. (optical coherence tomography)

  10. An Ecological Alternative to Snodgrass & Vanderwart: 360 High Quality Colour Images with Norms for Seven Psycholinguistic Variables

    PubMed Central

    Moreno-Martínez, Francisco Javier; Montoro, Pedro R.

    2012-01-01

    This work presents a new set of 360 high quality colour images belonging to 23 semantic subcategories. Two hundred and thirty-six Spanish speakers named the items and also provided data from seven relevant psycholinguistic variables: age of acquisition, familiarity, manipulability, name agreement, typicality and visual complexity. Furthermore, we also present lexical frequency data derived from Internet search hits. Apart from the high number of variables evaluated, knowing that it affects the processing of stimuli, this new set presents important advantages over other similar image corpi: (a) this corpus presents a broad number of subcategories and images; for example, this will permit researchers to select stimuli of appropriate difficulty as required, (e.g., to deal with problems derived from ceiling effects); (b) the fact of using coloured stimuli provides a more realistic, ecologically-valid, representation of real life objects. In sum, this set of stimuli provides a useful tool for research on visual object-and word- processing, both in neurological patients and in healthy controls. PMID:22662166

  11. 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.

  12. Modulation of the phenolic composition and colour of red wines subjected to accelerated ageing by controlling process variables.

    PubMed

    González-Sáiz, J M; Esteban-Díez, I; Rodríguez-Tecedor, S; Pérez-Del-Notario, N; Arenzana-Rámila, I; Pizarro, C

    2014-12-15

    The aim of the present work was to evaluate the effect of the main factors conditioning accelerated ageing processes (oxygen dose, chip dose, wood origin, toasting degree and maceration time) on the phenolic and chromatic profiles of red wines by using a multivariate strategy based on experimental design methodology. The results obtained revealed that the concentrations of monomeric anthocyanins and flavan-3-ols could be modified through the application of particular experimental conditions. This fact was particularly remarkable since changes in phenolic profile were closely linked to changes observed in chromatic parameters. The main strength of this study lies in the possibility of using its conclusions as a basis to make wines with specific colour properties based on quality criteria. To our knowledge, the influence of such a large number of alternative ageing parameters on wine phenolic composition and chromatic attributes has not been studied previously using a comprehensive experimental design methodology.

  13. Estimation of canopy attributes in beech forests using true colour digital images from a small fixed-wing UAV

    NASA Astrophysics Data System (ADS)

    Chianucci, Francesco; Disperati, Leonardo; Guzzi, Donatella; Bianchini, Daniele; Nardino, Vanni; Lastri, Cinzia; Rindinella, Andrea; Corona, Piermaria

    2016-05-01

    Accurate estimates of forest canopy are essential for the characterization of forest ecosystems. Remotely-sensed techniques provide a unique way to obtain estimates over spatially extensive areas, but their application is limited by the spectral and temporal resolution available from these systems, which is often not suited to meet regional or local objectives. The use of unmanned aerial vehicles (UAV) as remote sensing platforms has recently gained increasing attention, but their applications in forestry are still at an experimental stage. In this study we described a methodology to obtain rapid and reliable estimates of forest canopy from a small UAV equipped with a commercial RGB camera. The red, green and blue digital numbers were converted to the green leaf algorithm (GLA) and to the CIE L*a*b* colour space to obtain estimates of canopy cover, foliage clumping and leaf area index (L) from aerial images. Canopy attributes were compared with in situ estimates obtained from two digital canopy photographic techniques (cover and fisheye photography). The method was tested in beech forests. UAV images accurately quantified canopy cover even in very dense stand conditions, despite a tendency to not detecting small within-crown gaps in aerial images, leading to a measurement of a quantity much closer to crown cover estimated from in situ cover photography. Estimates of L from UAV images significantly agreed with that obtained from fisheye images, but the accuracy of UAV estimates is influenced by the appropriate assumption of leaf angle distribution. We concluded that true colour UAV images can be effectively used to obtain rapid, cheap and meaningful estimates of forest canopy attributes at medium-large scales. UAV can combine the advantage of high resolution imagery with quick turnaround series, being therefore suitable for routine forest stand monitoring and real-time applications.

  14. Viewing images of snakes accelerates making judgements of their colour in humans: red snake effect as an instance of 'emotional Stroop facilitation'.

    PubMed

    Shibasaki, Masahiro; Isomura, Tomoko; Masataka, Nobuo

    2014-11-01

    One of the most prevalent current psychobiological notions about human behaviour and emotion suggests that prioritization of threatening stimuli processing induces deleterious effects on task performance. In order to confirm its relevancy, 108 adults and 25 children were required to name the colour of images of snakes and flowers, using the pictorial emotional Stroop paradigm. When reaction time to answer the colour of each stimulus was measured, its value was found to decrease when snake images were presented when compared with when flower images were presented. Thus, contrary to the expectation from previous emotional Stroop paradigm research, emotions evoked by viewing images of snakes as a biologically relevant threatening stimulus were found to be likely to exert a facilitating rather than interfering effect on making judgements of their colour.

  15. Viewing images of snakes accelerates making judgements of their colour in humans: red snake effect as an instance of 'emotional Stroop facilitation'.

    PubMed

    Shibasaki, Masahiro; Isomura, Tomoko; Masataka, Nobuo

    2014-11-01

    One of the most prevalent current psychobiological notions about human behaviour and emotion suggests that prioritization of threatening stimuli processing induces deleterious effects on task performance. In order to confirm its relevancy, 108 adults and 25 children were required to name the colour of images of snakes and flowers, using the pictorial emotional Stroop paradigm. When reaction time to answer the colour of each stimulus was measured, its value was found to decrease when snake images were presented when compared with when flower images were presented. Thus, contrary to the expectation from previous emotional Stroop paradigm research, emotions evoked by viewing images of snakes as a biologically relevant threatening stimulus were found to be likely to exert a facilitating rather than interfering effect on making judgements of their colour. PMID:26064551

  16. Colour Vision: Understanding #TheDress.

    PubMed

    Brainard, David H; Hurlbert, Anya C

    2015-06-29

    A widely-viewed image of a dress elicits striking individual variation in colour perception. Experiments with multiple variants of the image suggest that the individual differences may arise through the action of visual mechanisms that normally stabilise object colour.

  17. A prominent colour front in False Bay, South Africa: Cross-frontal structure, composition and origin

    NASA Astrophysics Data System (ADS)

    Waldron, H. N.; Wainman, C. K.; Waldron, M. E.; Whittle, C.; Brundrit, G. B.

    2008-05-01

    Colour fronts are a frequent occurrence in False Bay, South Africa, and their occurrence has been the subject of previous study and anecdotal conjecture. The opportunity arose to make a cross-frontal study of this feature in November 2005. Photographs were taken and, subsequently, satellite imagery was obtained. Measurements were made of temperature, salinity, turbidity, dissolved oxygen, suspended solids, plant nutrients and chlorophyll a. Cross-frontal comparisons were also made on particulate material using a scanning electron microscope (SEM) and elemental dispersive x-ray (EDX) analysis. Frontal waters were milky white-green in colour, in stark contrast to the adjacent clearer, green-blue waters. The milky white-green water (MW-GW) was found to be warmer, (apparently) less saline, more turbid, richer in nitrate and silicate and had a higher chlorophyll a concentration. The dissolved oxygen signal was less pronounced, both water types being supersaturated. Paradoxically, in spite of the higher turbidity in the MW-GW, both water types had similar weights of suspended solids, although the MW-GW material was found to be more abundant and fragmentary when compared with its green-blue water (G-BW) counterpart. The MW-GW was rich in calcium whereas the G-BW was silicon enriched. The central findings of this study are that the strong southerly, onshore wind conditions prior to MW-GW formation introduced calcium-rich, fine particulates into the waters of the surf-zone. The sources of these particulates are thought to be the sea bed sediments and the sea/land interface. The particulates are close to neutral buoyancy enabling the MW-GW to persist over the time-scale of days. A mechanism reinforced by the warming of this water in the nearshore zone. The water was then advected by wind-forcing and subsequently, its own inertia around the north-west corner of False Bay, at which stage it was easily observed and sampled. It is suggested that the eventual collapse of the

  18. Colour, composition and eating quality of beef from the progeny of two Charolais sires.

    PubMed

    Maher, S C; Mullen, A M; Moloney, A P; Drennan, M J; Buckley, D J; Kerry, J P

    2004-05-01

    Eating quality and variation within eating quality attributes of beef from young bull progeny of a Charolais sire of average conformation heritability (CF44) (n=14) and young bull progeny of a Charolais sire of good conformation heritability (IC27) (n=16) were examined. The M. longissimus dorsi (up to 12th and/or 13th ribs) was excised 24 h post-slaughter and eating quality attributes analysed at 2, 7 and 14 days postmortem. While progeny muscularity and carcass weight reflected that of each sire, in general no variation was observed in the quality attributes. In addition no significant difference in mean values was evident between sire progenies for carcass and meat quality attributes examined. Significant variation was observed in colour after 2 days ageing, but this was not evident after 7 or 14 days ageing. Average sarcomere length did differ significantly (p<0.05) between progeny of both sire types (CF44=1.87 μm and IC27=1.77 μm), but did not appear to impact on tenderness. The similarity between the progeny of the average or good conformation sires examined in this experiment suggests such sires have no effect on the eating quality of their young bull beef progeny. PMID:22061118

  19. Are all the coloured galaxias the same?

    NASA Astrophysics Data System (ADS)

    Hidalgo-Gámez, A. M.; Miranda-Pérez, B. E.; Vega-Acevedo, I.; Castañeda, H.; Saviane, I.

    2016-06-01

    The coloured galaxies were recently discovered in the data-base of the SDSS. They are all compact and show unsual colours in the gri composite image. The most studied so far are those called "green peas" because of their green colour but there are bright blue, purple, red, orange, grey and pink. The green, purple and blue also share a large equivalent width in the oxygen forbbiden line [OIII]5007, larger than 200 Å, being more intense than Hα. This is quite unsual even for star forming galaxies. Although some authors have concluded that all three are the same kind of galaxies, we have studied them carefully and found out that there are important differences among the properties, including the scaling relations.

  20. Generalized satellite image processing: eight years of ocean colour data for any region on earth

    NASA Astrophysics Data System (ADS)

    Vanhellemont, Quinten; Ruddick, Kevin

    2011-11-01

    During the past decade, the world's oceans have been systematically observed by orbiting spectroradiometers such as MODIS and MERIS. These sensors have generated a huge amount of data with unprecedented temporal and spatial coverage. The data is freely available, but not always accessible for marine researchers with no image processing experience. In order to provide historical and current oceanographic parameters for the jellyfish forecasting in the JELLYFOR project, a tool for the generalized processing and archiving of satellite data was created (GRIMAS). Using this generalized software, the large amount of remote sensing data can be accessed, and parameters such as chlorophyll a concentration (CHL), sea surface temperature (SST) and total suspended matter concentration (TSM) can be extracted and gridded for any region on earth. Time-series and climatologies can be easily extracted from this data archive. The products generated can be based on the standard products, as supplied by space agencies, or can be new or regionally calibrated products. All available MODIS and MERIS L2 images from an eight year period (2003-2010) were processed in order to create a gridded dataset of CHL, SST (MODIS only) and of TSM for the three JELLYFOR regions. For two of the regions, data for an extended region was also processed. Multi-year composites (climatologies) of satellite data and time-series can provide a wealth of information for different projects in any region. Climatologies from the two sensors are in good agreement, while significant differences can occur on a scene per scene basis. Total suspended matter concentrations match favourably with in situ data derived from sensors on autonomous buoys. MODIS sea surface temperature corresponds closely to temperature continuously measured underway on research vessels.

  1. Recent progress in plasmonic colour filters for image sensor and multispectral applications

    NASA Astrophysics Data System (ADS)

    Pinton, Nadia; Grant, James; Choubey, Bhaskar; Cumming, David; Collins, Steve

    2016-04-01

    Using nanostructured thin metal films as colour filters offers several important advantages, in particular high tunability across the entire visible spectrum and some of the infrared region, and also compatibility with conventional CMOS processes. Since 2003, the field of plasmonic colour filters has evolved rapidly and several different designs and materials, or combination of materials, have been proposed and studied. In this paper we present a simulation study for a single- step lithographically patterned multilayer structure able to provide competitive transmission efficiencies above 40% and contemporary FWHM of the order of 30 nm across the visible spectrum. The total thickness of the proposed filters is less than 200 nm and is constant for every wavelength, unlike e.g. resonant cavity-based filters such as Fabry-Perot that require a variable stack of several layers according to the working frequency, and their passband characteristics are entirely controlled by changing the lithographic pattern. It will also be shown that a key to obtaining narrow-band optical response lies in the dielectric environment of a nanostructure and that it is not necessary to have a symmetric structure to ensure good coupling between the SPPs at the top and bottom interfaces. Moreover, an analytical method to evaluate the periodicity, given a specific structure and a desirable working wavelength, will be proposed and its accuracy demonstrated. This method conveniently eliminate the need to optimize the design of a filter numerically, i.e. by running several time-consuming simulations with different periodicities.

  2. Hue-specific colour memory impairment in an individual with intact colour perception and colour naming.

    PubMed

    Jakobson, L S; Pearson, P M; Robertson, B

    2008-01-15

    Cases of hue-selective dyschomatopsias, together with the results of recent optical imaging studies [Xiao, Y., Casti, A. R. R., Xiao, J., & Kaplan, E. (2006). A spatially organized representation of colour in macaque primary visual cortex. Perception, 35, ECVP Abstract Supplement; Xiao, Y., Wang, Y., & Felleman, D. J. (2003). A spatially organized representation of colour in macaque cortical area V2. Nature, 421, 535-539], have provided support for the idea that different colours are processed in spatially distinct regions of extrastriate cortex. In the present report, we provide evidence suggesting that a similar, but distinct, map may exist for representations of colour in memory. This evidence comes from observations of a young woman (QP) who demonstrates an isolated deficit in colour memory secondary to a concussive episode. Despite having normal colour perception and colour naming skills, and above-average memory skills in other domains, QP's ability to recall visually encoded colour information over short retention intervals is dramatically impaired. Her long-term memory for colour and her colour imagery skills are also abnormal. Surprisingly, however, these impairments are not seen with all hues; specifically, her ability to remember or imagine blue shades is spared. This interesting case contributes to the literature suggesting that colour perception, naming, and memory can be clinically dissociated, and provides insights into the organization of colour information in memory.

  3. Composite structures for magnetosphere imager spacecraft

    NASA Technical Reports Server (NTRS)

    Chu, Tsuchin

    1994-01-01

    Results of a trade study addressing the issues and benefits in using carbon fiber reinforced composites for the Magnetosphere Imager (MI) spacecraft are presented. The MI mission is now part of the Sun/Earth Connection Program. To qualify for this category, new technology and innovative methods to reduce the cost and size have to be considered. Topics addressed cover: (1) what is a composite, including advantages and disadvantages of composites and carbon/graphite fibers; and (2) structural design for MI, including composite design configuration, material selection, and analysis of composite structures.

  4. Colour vision: colouring the dark.

    PubMed

    Land, Michael F; Osorio, Daniel C

    2003-02-01

    Humans lose colour vision at night and it has often been assumed that this happens to other animals as well. It is not true of nocturnal moths, however: a recent study has shown that the elephant hawk moth makes use of trichromatic colour vision when seeking flowers by starlight.

  5. Colour Terms Affect Detection of Colour and Colour-Associated Objects Suppressed from Visual Awareness.

    PubMed

    Forder, Lewis; Taylor, Olivia; Mankin, Helen; Scott, Ryan B; Franklin, Anna

    2016-01-01

    The idea that language can affect how we see the world continues to create controversy. A potentially important study in this field has shown that when an object is suppressed from visual awareness using continuous flash suppression (a form of binocular rivalry), detection of the object is differently affected by a preceding word prime depending on whether the prime matches or does not match the object. This may suggest that language can affect early stages of vision. We replicated this paradigm and further investigated whether colour terms likewise influence the detection of colours or colour-associated object images suppressed from visual awareness by continuous flash suppression. This method presents rapidly changing visual noise to one eye while the target stimulus is presented to the other. It has been shown to delay conscious perception of a target for up to several minutes. In Experiment 1 we presented greyscale photos of objects. They were either preceded by a congruent object label, an incongruent label, or white noise. Detection sensitivity (d') and hit rates were significantly poorer for suppressed objects preceded by an incongruent label compared to a congruent label or noise. In Experiment 2, targets were coloured discs preceded by a colour term. Detection sensitivity was significantly worse for suppressed colour patches preceded by an incongruent colour term as compared to a congruent term or white noise. In Experiment 3 targets were suppressed greyscale object images preceded by an auditory presentation of a colour term. On congruent trials the colour term matched the object's stereotypical colour and on incongruent trials the colour term mismatched. Detection sensitivity was significantly poorer on incongruent trials than congruent trials. Overall, these findings suggest that colour terms affect awareness of coloured stimuli and colour- associated objects, and provide new evidence for language-perception interaction in the brain. PMID:27023274

  6. Colour Terms Affect Detection of Colour and Colour-Associated Objects Suppressed from Visual Awareness.

    PubMed

    Forder, Lewis; Taylor, Olivia; Mankin, Helen; Scott, Ryan B; Franklin, Anna

    2016-01-01

    The idea that language can affect how we see the world continues to create controversy. A potentially important study in this field has shown that when an object is suppressed from visual awareness using continuous flash suppression (a form of binocular rivalry), detection of the object is differently affected by a preceding word prime depending on whether the prime matches or does not match the object. This may suggest that language can affect early stages of vision. We replicated this paradigm and further investigated whether colour terms likewise influence the detection of colours or colour-associated object images suppressed from visual awareness by continuous flash suppression. This method presents rapidly changing visual noise to one eye while the target stimulus is presented to the other. It has been shown to delay conscious perception of a target for up to several minutes. In Experiment 1 we presented greyscale photos of objects. They were either preceded by a congruent object label, an incongruent label, or white noise. Detection sensitivity (d') and hit rates were significantly poorer for suppressed objects preceded by an incongruent label compared to a congruent label or noise. In Experiment 2, targets were coloured discs preceded by a colour term. Detection sensitivity was significantly worse for suppressed colour patches preceded by an incongruent colour term as compared to a congruent term or white noise. In Experiment 3 targets were suppressed greyscale object images preceded by an auditory presentation of a colour term. On congruent trials the colour term matched the object's stereotypical colour and on incongruent trials the colour term mismatched. Detection sensitivity was significantly poorer on incongruent trials than congruent trials. Overall, these findings suggest that colour terms affect awareness of coloured stimuli and colour- associated objects, and provide new evidence for language-perception interaction in the brain.

  7. Colour Terms Affect Detection of Colour and Colour-Associated Objects Suppressed from Visual Awareness

    PubMed Central

    Forder, Lewis; Taylor, Olivia; Mankin, Helen; Scott, Ryan B.; Franklin, Anna

    2016-01-01

    The idea that language can affect how we see the world continues to create controversy. A potentially important study in this field has shown that when an object is suppressed from visual awareness using continuous flash suppression (a form of binocular rivalry), detection of the object is differently affected by a preceding word prime depending on whether the prime matches or does not match the object. This may suggest that language can affect early stages of vision. We replicated this paradigm and further investigated whether colour terms likewise influence the detection of colours or colour-associated object images suppressed from visual awareness by continuous flash suppression. This method presents rapidly changing visual noise to one eye while the target stimulus is presented to the other. It has been shown to delay conscious perception of a target for up to several minutes. In Experiment 1 we presented greyscale photos of objects. They were either preceded by a congruent object label, an incongruent label, or white noise. Detection sensitivity (d’) and hit rates were significantly poorer for suppressed objects preceded by an incongruent label compared to a congruent label or noise. In Experiment 2, targets were coloured discs preceded by a colour term. Detection sensitivity was significantly worse for suppressed colour patches preceded by an incongruent colour term as compared to a congruent term or white noise. In Experiment 3 targets were suppressed greyscale object images preceded by an auditory presentation of a colour term. On congruent trials the colour term matched the object’s stereotypical colour and on incongruent trials the colour term mismatched. Detection sensitivity was significantly poorer on incongruent trials than congruent trials. Overall, these findings suggest that colour terms affect awareness of coloured stimuli and colour- associated objects, and provide new evidence for language-perception interaction in the brain. PMID:27023274

  8. Colouring fabrics with excimer lasers to simulate encoded images: the case of the Shroud of Turin

    NASA Astrophysics Data System (ADS)

    Di Lazzaro, P.; Baldacchini, G.; Fanti, G.; Murra, D.; Santoni, A.

    2008-10-01

    The faint body image embedded into the Turin Shroud has not yet explained by traditional science. We present experimental results of excimer laser irradiation (wavelengths 308 nm and 193 nm) of a raw linen fabric and of a linen cloth, seeking for a possible mechanism of image formation. The permanent coloration of both linens is a threshold effect on the laser beam intensity and it can be achieved only in a surprisingly narrow range of irradiation parameters: the shorter the wavelength, the narrower the range. We also obtained the first direct evidence of latent images impressed on linen that appear in a relatively long period (one year) after a laser irradiation that at first did not generate a clear image. The results are compared to the characteristics of the Turin Shroud, commenting the possibility that a burst of directional ultraviolet radiation may have played a role in the formation of the Shroud image.

  9. Composite model of a 3-D image

    NASA Technical Reports Server (NTRS)

    Dukhovich, I. J.

    1980-01-01

    This paper presents a composite model of a moving (3-D) image especially useful for the sequential image processing and encoding. A non-linear predictor based on the composite model is described. The performance of this predictor is used as a measure of the validity of the model for a real image source. The minimization of a total mean square prediction error provides an inequality which determines a condition for the profitable use of the composite model and can serve as a decision device for the selection of the number of subsources within the model. The paper also describes statistical properties of the prediction error and contains results of computer simulation of two non-linear predictors in the case of perfect classification between subsources.

  10. Features of image colouring in a projection microscope based on a copper vapour laser with an unstable resonator and a Glan prism

    SciTech Connect

    Karpukhin, Vyacheslav T; Malikov, Mikhail M; Mendeleev, Vladimir Ya; Skovorod'ko, Sergei N; Klimovskii, Ivan I

    2004-06-30

    The effect of properties of metal surfaces on the colour of their images obtained with a 510.6/578.2-nm copper vapour laser projection microscope is studied. The metal surfaces were exposed to laser radiation polarised by 99 % in the horizontal plane. Radiation used for surface imaging is predominantly polarised in the vertical plane and is coupled out of the resonator in the direction perpendicular to its optical axis. It is found that the ratio of laser radiation powers at wavelengths 510.6 and 578.2 nm determining the image colour is dependent on the total reflection coefficients, the curvature, and statistical characteristics of the surface roughness. (laser applications and other topics in quantum electronics)

  11. Colour blindness.

    PubMed

    Gordon, N

    1998-03-01

    The physiology of colour vision is discussed; as is the way in which the human eye can detect various combinations of red, green and blue. Red-green colour blindness, with X-linked inheritance, is the most common, but other types are also considered. Methods of testing relating to the age of the child are reviewed. The use of colours in teaching is widespread, but there is controversy over the difficulties this may cause a colour blind child. A review of the literature does not reveal much information on this, and any problems that do arise are likely to be individual to the child, and to depend on such factors as overall intelligence, the attitude of the teacher, and the personality of the child. There is not doubt that it is essential to recognise colour vision defects when it comes to choosing a career, and that tests must be done during secondary schooling, but in order to avoid some affected children being disadvantaged there is enough evidence to support testing at school entry.

  12. Changes in texture, colour and fatty acid composition of male and female pig shoulder fat due to different dietary fat sources.

    PubMed

    Hallenstvedt, E; Kjos, N P; Overland, M; Thomassen, M

    2012-03-01

    Two experiments with 72 slaughter pigs in each were conducted. Entire males and females were individually fed restricted. Palm kernel-, soybean- and fish-oil were used in varying combinations, giving different dietary fat levels (29-80g/kg) and iodine values ranging from 50 to 131. Shoulder fat was analysed for fatty acid composition (inner and outer layer), firmness and colour. A clear dose-response relationship was seen between fatty acids in diets and in shoulder fat. Interestingly, the very long chain n-3 fatty acids seemed to be deposited more efficiently when additional fat was included in the diet. Both high and low dietary iodine values changed towards less extreme iodine values in fat. Low-fat diets enhanced de novo synthesis of fatty acids. Males revealed a higher percentage of PUFA and a lower percentage of C18:1 and MUFA. Fat firmness, but not colour, was influenced by sex and dietary fat source.

  13. How to use transparent diazo colour film for interpretation of LANDSAT images

    NASA Astrophysics Data System (ADS)

    Malan, O. G.

    1981-05-01

    Instruction manual to further the practical application of space techniques in developing countries. This manual is aimed at potential users of LANDSAT data with some basic training in scientific disciplines, but without special training in photographic darkroom techniques. The procedures described here require an absolute minimum of equipment and material other than positive transparencies of LANDSAT MSS images and suitable diazo material.

  14. Bright Retinal Lesions Detection using Colour Fundus Images Containing Reflective Features

    SciTech Connect

    Giancardo, Luca; Karnowski, Thomas Paul; Chaum, Edward; Meriaudeau, Fabrice; Tobin Jr, Kenneth William; Li, Yaquin

    2009-01-01

    In the last years the research community has developed many techniques to detect and diagnose diabetic retinopathy with retinal fundus images. This is a necessary step for the implementation of a large scale screening effort in rural areas where ophthalmologists are not available. In the United States of America, the incidence of diabetes is worryingly increasing among the young population. Retina fundus images of patients younger than 20 years old present a high amount of reflection due to the Nerve Fibre Layer (NFL), the younger the patient the more these reflections are visible. To our knowledge we are not aware of algorithms able to explicitly deal with this type of reflection artefact. This paper presents a technique to detect bright lesions also in patients with a high degree of reflective NFL. First, the candidate bright lesions are detected using image equalization and relatively simple histogram analysis. Then, a classifier is trained using texture descriptor (Multi-scale Local Binary Patterns) and other features in order to remove the false positives in the lesion detection. Finally, the area of the lesions is used to diagnose diabetic retinopathy. Our database consists of 33 images from a telemedicine network currently developed. When determining moderate to high diabetic retinopathy using the bright lesions detected the algorithm achieves a sensitivity of 100% at a specificity of 100% using hold-one-out testing.

  15. The uses of colour vision: behavioural and physiological distinctiveness of colour stimuli.

    PubMed Central

    Derrington, Andrew M; Parker, Amanda; Barraclough, Nick E; Easton, Alexander; Goodson, G R; Parker, Kris S; Tinsley, Chris J; Webb, Ben S

    2002-01-01

    Colour and greyscale (black and white) pictures look different to us, but it is not clear whether the difference in appearance is a consequence of the way our visual system uses colour signals or a by-product of our experience. In principle, colour images are qualitatively different from greyscale images because they make it possible to use different processing strategies. Colour signals provide important cues for segmenting the image into areas that represent different objects and for linking together areas that represent the same object. If this property of colour signals is exploited in visual processing we would expect colour stimuli to look different, as a class, from greyscale stimuli. We would also expect that adding colour signals to greyscale signals should change the way that those signals are processed. We have investigated these questions in behavioural and in physiological experiments. We find that male marmosets (all of which are dichromats) rapidly learn to distinguish between colour and greyscale copies of the same images. The discrimination transfers to new image pairs, to new colours and to image pairs in which the colour and greyscale images are spatially different. We find that, in a proportion of neurons recorded in the marmoset visual cortex, colour-shifts in opposite directions produce similar enhancements of the response to a luminance stimulus. We conclude that colour is, both behaviourally and physiologically, a distinctive property of images. PMID:12217169

  16. Digital colour management system for colour parameters reconstruction

    NASA Astrophysics Data System (ADS)

    Grudzinski, Karol; Lasmanowicz, Piotr; Assis, Lucas M. N.; Pawlicka, Agnieszka; Januszko, Adam

    2013-10-01

    Digital Colour Management System (DCMS) and its application to new adaptive camouflage system are presented in this paper. The DCMS is a digital colour rendering method which would allow for transformation of a real image into a set of colour pixels displayed on a computer monitor. Consequently, it can analyse pixels' colour which comprise images of the environment such as desert, semi-desert, jungle, farmland or rocky mountain in order to prepare an adaptive camouflage pattern most suited for the terrain. This system is described in present work as well as the use the subtractive colours mixing method to construct the real time colour changing electrochromic window/pixel (ECD) for camouflage purpose. The ECD with glass/ITO/Prussian Blue(PB)/electrolyte/CeO2-TiO2/ITO/glass configuration was assembled and characterized. The ECD switched between green and yellow after +/-1.5 V application and the colours have been controlled by Digital Colour Management System and described by CIE LAB parameters.

  17. Optoelectronics: Colour-selective photodiodes

    NASA Astrophysics Data System (ADS)

    Johnston, Michael B.

    2015-10-01

    Perovskite semiconductors have altered the landscape of solar cell research. Now researchers show that these materials may also offer a flexible platform for colour imaging and wavelength-selective sensing.

  18. An effective automated system for grading severity of retinal arteriovenous nicking in colour retinal images.

    PubMed

    Roy, Pallab Kanti; Nguyen, Uyen T V; Bhuiyan, Alauddin; Ramamohanarao, Kotagiri

    2014-01-01

    Retinal arteriovenous (AV) nicking is a precursor for hypertension, stroke and other cardiovascular diseases. In this paper, an effective method is proposed for the analysis of retinal venular widths to automatically classify the severity level of AV nicking. We use combination of intensity and edge information of the vein to compute its widths. The widths at various sections of the vein near the crossover point are then utilized to train a random forest classifier to classify the severity of AV nicking. We analyzed 47 color retinal images obtained from two population based studies for quantitative evaluation of the proposed method. We compare the detection accuracy of our method with a recently published four class AV nicking classification method. Our proposed method shows 64.51% classification accuracy in-contrast to the reported classification accuracy of 49.46% by the state of the art method. PMID:25571443

  19. Potential of multispectral imaging for real-time determination of colour change and moisture distribution in carrot slices during hot air dehydration.

    PubMed

    Liu, Changhong; Liu, Wei; Lu, Xuzhong; Chen, Wei; Yang, Jianbo; Zheng, Lei

    2016-03-15

    Colour and moisture content are important indices in quality monitoring of dehydrating carrot slices during dehydration process. This study investigated the potential of using multispectral imaging for real-time and non-destructive determination of colour change and moisture distribution during the hot air dehydration of carrot slices. Multispectral reflectance images, ranging from 405 to 970 nm, were acquired and then calibrated based on three chemometrics models of partial least squares (PLS), least squares-support vector machines (LS-SVM), and back propagation neural network (BPNN), respectively. Compared with PLS and LS-SVM, BPNN considerably improved the prediction performance with coefficient of determination in prediction (RP(2))=0.991, root-mean-square error of prediction (RMSEP)=1.482% and residual predictive deviation (RPD)=11.378 for moisture content. It was concluded that multispectral imaging has an excellent potential for rapid, non-destructive and simultaneous determination of colour change and moisture distribution of carrot slices during dehydration. PMID:26575720

  20. Potential of multispectral imaging for real-time determination of colour change and moisture distribution in carrot slices during hot air dehydration.

    PubMed

    Liu, Changhong; Liu, Wei; Lu, Xuzhong; Chen, Wei; Yang, Jianbo; Zheng, Lei

    2016-03-15

    Colour and moisture content are important indices in quality monitoring of dehydrating carrot slices during dehydration process. This study investigated the potential of using multispectral imaging for real-time and non-destructive determination of colour change and moisture distribution during the hot air dehydration of carrot slices. Multispectral reflectance images, ranging from 405 to 970 nm, were acquired and then calibrated based on three chemometrics models of partial least squares (PLS), least squares-support vector machines (LS-SVM), and back propagation neural network (BPNN), respectively. Compared with PLS and LS-SVM, BPNN considerably improved the prediction performance with coefficient of determination in prediction (RP(2))=0.991, root-mean-square error of prediction (RMSEP)=1.482% and residual predictive deviation (RPD)=11.378 for moisture content. It was concluded that multispectral imaging has an excellent potential for rapid, non-destructive and simultaneous determination of colour change and moisture distribution of carrot slices during dehydration.

  1. Progress in digestive endoscopy: Flexible Spectral Imaging Colour Enhancement (FICE)-technical review

    PubMed Central

    Negreanu, L; Preda, CM; Ionescu, D; Ferechide, D

    2015-01-01

    Background. A substantial advance in digestive endoscopy that has been made during the last decade is represented by digital chromoendoscopy, which was developed as a quicker and sometimes better alternative to the gold standard of dye spraying. Fujifilm developed a virtual coloration technique called Flexible spectral Imaging Color Enhancement (FICE). FICE provides a better detection of lesions of “minimal” esophagitis, of dysplasia in Barrett’s esophagus and of squamous cell esophageal cancer. The use of FICE resulted in an improvement in the visualization of the early gastric cancer, being less invasive, and time consuming than the classic dye methods. Current evidence does not support FICE for screening purposes in colon cancer but it definitely improves characterization of colonic lesions. Its use in inflammatory bowel disease is still controversial and in video capsule endoscopy is considered a substantial progress. Conclusions. The use of FICE endoscopy in routine clinical practice can increase the diagnostic yield and can provide a better characterization of lesions. Future studies to validate its use, the good choice of channels, and the “perfect indications” and to provide common definitions and classifications are necessary. PMID:26664462

  2. Automatic extraction of retinal features from colour retinal images for glaucoma diagnosis: a review.

    PubMed

    Haleem, Muhammad Salman; Han, Liangxiu; van Hemert, Jano; Li, Baihua

    2013-01-01

    Glaucoma is a group of eye diseases that have common traits such as, high eye pressure, damage to the Optic Nerve Head and gradual vision loss. It affects peripheral vision and eventually leads to blindness if left untreated. The current common methods of pre-diagnosis of Glaucoma include measurement of Intra-Ocular Pressure (IOP) using Tonometer, Pachymetry, Gonioscopy; which are performed manually by the clinicians. These tests are usually followed by Optic Nerve Head (ONH) Appearance examination for the confirmed diagnosis of Glaucoma. The diagnoses require regular monitoring, which is costly and time consuming. The accuracy and reliability of diagnosis is limited by the domain knowledge of different ophthalmologists. Therefore automatic diagnosis of Glaucoma attracts a lot of attention. This paper surveys the state-of-the-art of automatic extraction of anatomical features from retinal images to assist early diagnosis of the Glaucoma. We have conducted critical evaluation of the existing automatic extraction methods based on features including Optic Cup to Disc Ratio (CDR), Retinal Nerve Fibre Layer (RNFL), Peripapillary Atrophy (PPA), Neuroretinal Rim Notching, Vasculature Shift, etc., which adds value on efficient feature extraction related to Glaucoma diagnosis.

  3. Covert colour processing in colour agnosia.

    PubMed

    Nijboer, Tanja C W; van Zandvoort, Martine J E; de Haan, Edward H F

    2006-01-01

    Patients with colour agnosia can perceive colours and are able to match coloured patches on hue, but are unable to identify or categorise colours. It is a rare condition and there is as yet no agreement on the clinical definition or a generally accepted explanation. In line with observations from object agnosia and prosopagnosia, we hypothesised that (some of) these patients might still be able to process colour information at an implicit level. In this study, we investigated this possibility of implicit access to colour semantics and colour names in a man (MAH) who suffers from developmental colour agnosia. We designed two experimental computer tasks: an associative colour priming task with a lexical decision response and a reversed Stroop task. The results of these experiments suggest that there is indeed automatic processing of colour, although MAH was unable to explicitly use colour information.

  4. Meso-scale imaging of composite materials

    SciTech Connect

    Grandin, R.; Gray, J.

    2015-03-31

    The performance of composite materials is controlled by the interaction between the individual components as well as the mechanical characteristics of the components themselves. Geometric structure on the meso-scale, where the length-scales are of the same order as the material granularity, plays a key role in controlling material performance and having a quantitative means of characterizing this structure is crucial in developing our understanding of NDE technique signatures of early damage states. High-resolution computed tomography (HRCT) provides an imaging capability which can resolve these structures for many composite materials. Coupling HRCT with three-dimensional physics-based image processing enables quantitative characterization of the meso-scale structure. Taking sequences of these damage states provides a means to structurally observe the damages evolution. We will discuss the limits of present 3DCT capability and challenges for improving this means to rapidly generate structural information of a composite and of the damage. In this presentation we will demonstrate the imaging capability of HRCT.

  5. Colour assortative pairing in a colour polymorphic lizard is independent of population morph diversity

    NASA Astrophysics Data System (ADS)

    Pérez i de Lanuza, Guillem; Font, Enrique; Carretero, Miguel Ángel

    2016-10-01

    Previous work with a colour polymorphic population of Podarcis muralis (Lacertidae) revealed that lizards pair by ventral colour, favouring the same colour (i.e. homomorphic) pairs. Such assortative pairing, which probably results in colour assortative mating, can have consequences for the genetic structure of the population and potentially promote speciation. The population previously studied, located in the Pyrenees, encompasses white, yellow and orange animals, as well as intermediate white-orange and yellow-orange morphs. However, other Pyrenean populations of P. muralis have less ventral colour morphs. Our aim in this study is to test the generality of the assortative colour pairing system, extending our previous analyses to populations with different morph compositions and frequencies. The results show that the assortative pattern of pairing is similar in all the populations analysed and, hence, independent of morph composition and not restricted to pentamorphic populations. This suggests that assortative pairing by colour is a general phenomenon for colour polymorphic populations of P. muralis.

  6. Colour assortative pairing in a colour polymorphic lizard is independent of population morph diversity.

    PubMed

    Pérez I de Lanuza, Guillem; Font, Enrique; Carretero, Miguel Ángel

    2016-10-01

    Previous work with a colour polymorphic population of Podarcis muralis (Lacertidae) revealed that lizards pair by ventral colour, favouring the same colour (i.e. homomorphic) pairs. Such assortative pairing, which probably results in colour assortative mating, can have consequences for the genetic structure of the population and potentially promote speciation. The population previously studied, located in the Pyrenees, encompasses white, yellow and orange animals, as well as intermediate white-orange and yellow-orange morphs. However, other Pyrenean populations of P. muralis have less ventral colour morphs. Our aim in this study is to test the generality of the assortative colour pairing system, extending our previous analyses to populations with different morph compositions and frequencies. The results show that the assortative pattern of pairing is similar in all the populations analysed and, hence, independent of morph composition and not restricted to pentamorphic populations. This suggests that assortative pairing by colour is a general phenomenon for colour polymorphic populations of P. muralis.

  7. Printing colour at the optical diffraction limit.

    PubMed

    Kumar, Karthik; Duan, Huigao; Hegde, Ravi S; Koh, Samuel C W; Wei, Jennifer N; Yang, Joel K W

    2012-09-01

    The highest possible resolution for printed colour images is determined by the diffraction limit of visible light. To achieve this limit, individual colour elements (or pixels) with a pitch of 250 nm are required, translating into printed images at a resolution of ∼100,000 dots per inch (d.p.i.). However, methods for dispensing multiple colourants or fabricating structural colour through plasmonic structures have insufficient resolution and limited scalability. Here, we present a non-colourant method that achieves bright-field colour prints with resolutions up to the optical diffraction limit. Colour information is encoded in the dimensional parameters of metal nanostructures, so that tuning their plasmon resonance determines the colours of the individual pixels. Our colour-mapping strategy produces images with both sharp colour changes and fine tonal variations, is amenable to large-volume colour printing via nanoimprint lithography, and could be useful in making microimages for security, steganography, nanoscale optical filters and high-density spectrally encoded optical data storage.

  8. Colour, composition and quality of M. longissimus dorsi and M. extensor carpi radialis of steers housed on straw or concrete slats or accommodated outdoors on wood-chips.

    PubMed

    Dunne, P G; Rogalski, J; Moreno, T; Monahan, F J; French, P; Moloney, A P

    2008-08-01

    Forty-five Charolais crossbred steers were offered a common diet and accommodated either outside on wood-chips (OWP, 18m(2)/head) or in a naturally-ventilated building in slatted-floor pens (SLA, 2.5m(2)/500kg bodyweight) or in straw-bedded pens (STR, 4m(2)/head) for 132 days. Carcass weight averaged 351, 362, and 372 (sed 6.63)kg (P<0.05), for SLA, STR and OWP, respectively. Accommodation system did not affect the colour, drip loss, shear force or composition of Musculus longissimus dorsi (LD) or Musculus extensor carpi radialis (ECR) muscles or the sensory characteristics of LD. The ultimate pH of ECR was highest (P<0.05) for OWP steers, while their LD was darker at 2 days post-mortem than LD from STR steers. It is concluded that accommodating cattle on OWP had a minor transient effect on beef colour and no impact on beef composition or eating quality. PMID:22063032

  9. Carotenoid compositions of coloured tomato cultivars and contribution to antioxidant activities and protection against H(2)O(2)-induced cell death in H9c2.

    PubMed

    Li, Hongyan; Deng, Zeyuan; Liu, Ronghua; Loewen, Steven; Tsao, Rong

    2013-01-15

    The carotenoid compositions, antioxidant activities and the potential cardio-protective role of 13 tomato cultivars with distinct colour were studied. Colour coordinates were evaluated by colorimeter and the carotenoid compositions were analysed by UPLC. Red tomatoes had the highest total carotenoid contents (TCC) and antioxidant activities, followed by purple, orange, pink and yellow ones. The TCC were 120.5-278.0 μg/gDW, and the antioxidant activities were 21.32-40.07 μmolTE/gDW (PCL), 64.42-89.98% (DPPH) and 10.47-13.76 μmolTE/g DW (ORAC), respectively. The lipophilic extracts were also found to prevent cell death in a cell-based model system using cardiac H9c2 cells and H(2)O(2), via attenuation of the caspase-3 and matrix metalloproteinase-2 activities. The extracts of different tomatoes showed strong but different antioxidant activities. Roles of total and individual carotenoids in the antioxidant activities were studied and lycopene showed the highest correlation. Results of this study can be used to guide the development of new tomato cultivars and functional foods, and benefit the consumers. PMID:23122140

  10. Sonographic imaging of extra-testicular focal lesions: comparison of grey-scale, colour Doppler and contrast-enhanced ultrasound.

    PubMed

    Rafailidis, Vasileios; Robbie, Hasti; Konstantatou, Eleni; Huang, Dean Y; Deganello, Annamaria; Sellars, Maria E; Cantisani, Vito; Isidori, Andrea M; Sidhu, Paul S

    2016-02-01

    Extra-testicular lesions are usually benign but present with nonspecific grey-scale sonography findings. This study assesses conventional sonographic characteristics in the differentiation of extra-testicular tumoural from inflammatory lesions and whether contrast-enhanced ultrasound has a role. A retrospective database analysis was performed. All patients were examined by experienced sonographers employing standard techniques combining grey-scale, colour Doppler sonography and contrast-enhanced ultrasound. Features recorded were: clinical symptoms, size, location, echogenicity, colour Doppler sonography and contrast-enhanced ultrasound enhancement. Vascularity on colour Doppler sonography and contrast-enhanced ultrasound was graded and compared. The lesions were classified as tumoural or inflammatory. The Chi-square test was used to analyse the sonographic patterns and kappa coefficient to measure the agreement between colour Doppler sonography and contrast-enhanced ultrasound. A total of 30 lesions were reviewed (median diameter 12 mm, range 5-80 mm, median age 52 years, range 18-86 years), including 13/30 tumoural and 17/30 inflammatory lesions. Lesions were hypoechoic (n = 12), isoechoic (n = 6), hyperechoic (n = 2) or mixed (n = 10). Grey-scale characteristics of tumoural vs. inflammatory lesions differed significantly (P = 0.026). On colour Doppler sonography, lesions had no vessels (n = 16), 2-3 vessels (n = 10) and ≥4 vessels (n = 4). On contrast-enhanced ultrasound, lesions showed no vascularity (n = 17), perfusion similar to testis (n = 7) and higher (n = 6). All abscesses identified (n = 9) showed no vascularity on both colour Doppler sonography and contrast-enhanced ultrasound. There was good agreement between these techniques in evaluating vascularity (κ = 0.719) and no significant difference between colour Doppler sonography and contrast-enhanced ultrasound of tumoural vs. inflammatory lesions

  11. What Colour Is a Shadow?

    ERIC Educational Resources Information Center

    Hughes, S. W.

    2009-01-01

    What colour is a shadow? Black, grey, or some other colour? This article describes how to use a digital camera to test the hypothesis that a shadow under a clear blue sky has a blue tint. A white sheet of A4 paper was photographed in full sunlight and in shadow under a clear blue sky. The images were analysed using a shareware program called…

  12. The colour wheels of art, perception, science and physiology

    NASA Astrophysics Data System (ADS)

    Harkness, Nick

    2006-06-01

    Colour is not the domain of any one discipline be it art, philosophy, psychology or science. Each discipline has its own colour wheel and this presentation examines the origins and philosophies behind the colour circles of Art, Perception, Science and Physiology (after image) with reference to Aristotle, Robert Boyle, Leonardo da Vinci, Goethe, Ewald Hering and Albert Munsell. The paper analyses and discusses the differences between the four colour wheels using the Natural Colour System® notation as the reference for hue (the position of colours within each of the colour wheels). Examination of the colour wheels shows the dominance of blue in the wheels of art, science and physiology particularly at the expense of green. This paper does not consider the three-dimensionality of colour space its goal was to review the hue of a colour with regard to its position on the respective colour wheels.

  13. GEMAS: Colours of dry and moist agricultural soil samples of Europe

    NASA Astrophysics Data System (ADS)

    Klug, Martin; Fabian, Karl; Reimann, Clemens

    2016-04-01

    High resolution HDR colour images of all Ap samples from the GEMAS survey were acquired using a GeoTek Linescan camera. Three measurements of dry and wet samples with increasing exposure time and increasing illumination settings produced a set of colour images at 50μm resolution. Automated image processing was used to calibrate the six images per sample with respect to the synchronously measured X-Rite colorchecker chart. The calibrated images were then fit to Munsell soil colours that were measured in the same way. The results provide overview maps of dry and moist European soil colours. Because colour is closely linked to iron mineralogy, carbonate, silicate and organic carbon content the results can be correlated to magnetic, mineralogical, and geochemical properties. In combination with the full GEMAS chemical and physical measurements, this yields a valuable data set for calibration and interpretation of visible satellite colour data with respect to chemical composition and geological background, soil moisture, and soil degradation. This data set will help to develop new methods for world-wide characterization and monitoring of agricultural soils which is essential for quantifying geologic and human impact on the critical zone environment. It furthermore enables the scientific community and governmental authorities to monitor consequences of climatic change, to plan and administrate economic and ecological land use, and to use the data set for forensic applications.

  14. Colour Vision: Understanding #TheDress.

    PubMed

    Brainard, David H; Hurlbert, Anya C

    2015-06-29

    A widely-viewed image of a dress elicits striking individual variation in colour perception. Experiments with multiple variants of the image suggest that the individual differences may arise through the action of visual mechanisms that normally stabilise object colour. PMID:26126278

  15. Color Composite Image of the Supernova Remnant

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This image is a color composite of the supernova remnant E0102-72: x-ray (blue), optical (green), and radio (red). E0102-72 is the remnant of a star that exploded in a nearby galaxy known as the Small Magellanic Cloud. The star exploded outward at speeds in excess of 20 million kilometers per hour (12 million mph) and collided with surrounding gas. This collision produced two shock waves, or cosmic sonic booms, one traveling outward, and the other rebounding back into the material ejected by the explosion. The radio image, shown in red, was made using the Australia Telescope Compact Array. The radio waves are due to extremely high-energy electrons spiraling around magnetic field lines in the gas and trace the outward moving shock wave. The Chandra X-ray Observatory image, shown in blue, shows gas that has been heated to millions of degrees by the rebounding, or reverse shock wave. The x-ray data show that this gas is rich in oxygen and neon. These elements were created by nuclear reactions inside the star and hurled into space by the supernova. The Hubble Space Telescope optical image, shown in green, shows dense clumps of oxygen gas that have 'cooled' to about 30,000 degrees. Photo Credit: X-ray (NASA/CXC/SAO); optical (NASA/HST): radio: (ACTA)

  16. Automated colour identification in melanocytic lesions.

    PubMed

    Sabbaghi, S; Aldeen, M; Garnavi, R; Varigos, G; Doliantis, C; Nicolopoulos, J

    2015-08-01

    Colour information plays an important role in classifying skin lesion. However, colour identification by dermatologists can be very subjective, leading to cases of misdiagnosis. Therefore, a computer-assisted system for quantitative colour identification is highly desirable for dermatologists to use. Although numerous colour detection systems have been developed, few studies have focused on imitating the human visual perception of colours in melanoma application. In this paper we propose a new methodology based on QuadTree decomposition technique for automatic colour identification in dermoscopy images. Our approach mimics the human perception of lesion colours. The proposed method is trained on a set of 47 images from NIH dataset and applied to a test set of 190 skin lesions obtained from PH2 dataset. The results of our proposed method are compared with a recently reported colour identification method using the same dataset. The effectiveness of our method in detecting colours in dermoscopy images is vindicated by obtaining approximately 93% accuracy when the CIELab1 colour space is used. PMID:26736928

  17. Thermographic Imaging of Defects in Anisotropic Composites

    NASA Technical Reports Server (NTRS)

    Plotnikov, Y. A.; Winfree, W. P.

    2000-01-01

    Composite materials are of increasing interest to the aerospace industry as a result of their weight versus performance characteristics. One of the disadvantages of composites is the high cost of fabrication and post inspection with conventional ultrasonic scanning systems. The high cost of inspection is driven by the need for scanning systems which can follow large curve surfaces. Additionally, either large water tanks or water squirters are required to couple the ultrasonics into the part. Thermographic techniques offer significant advantages over conventional ultrasonics by not requiring physical coupling between the part and sensor. The thermographic system can easily inspect large curved surface without requiring a surface following scanner. However, implementation of Thermal Nondestructive Evaluations (TNDE) for flaw detection in composite materials and structures requires determining its limit. Advanced algorithms have been developed to enable locating and sizing defects in carbon fiber reinforced plastic (CFRP). Thermal Tomography is a very promising method for visualizing the size and location of defects in materials such as CFRP. However, further investigations are required to determine its capabilities for inspection of thick composites. In present work we have studied influence of the anisotropy on the reconstructed image of a defect generated by an inversion technique. The composite material is considered as homogeneous with macro properties: thermal conductivity K, specific heat c, and density rho. The simulation process involves two sequential steps: solving the three dimensional transient heat diffusion equation for a sample with a defect, then estimating the defect location and size from the surface spatial and temporal thermal distributions (inverse problem), calculated from the simulations.

  18. Automatic thermographic image defect detection of composites

    NASA Astrophysics Data System (ADS)

    Luo, Bin; Liebenberg, Bjorn; Raymont, Jeff; Santospirito, SP

    2011-05-01

    Detecting defects, and especially reliably measuring defect sizes, are critical objectives in automatic NDT defect detection applications. In this work, the Sentence software is proposed for the analysis of pulsed thermography and near IR images of composite materials. Furthermore, the Sentence software delivers an end-to-end, user friendly platform for engineers to perform complete manual inspections, as well as tools that allow senior engineers to develop inspection templates and profiles, reducing the requisite thermographic skill level of the operating engineer. Finally, the Sentence software can also offer complete independence of operator decisions by the fully automated "Beep on Defect" detection functionality. The end-to-end automatic inspection system includes sub-systems for defining a panel profile, generating an inspection plan, controlling a robot-arm and capturing thermographic images to detect defects. A statistical model has been built to analyze the entire image, evaluate grey-scale ranges, import sentencing criteria and automatically detect impact damage defects. A full width half maximum algorithm has been used to quantify the flaw sizes. The identified defects are imported into the sentencing engine which then sentences (automatically compares analysis results against acceptance criteria) the inspection by comparing the most significant defect or group of defects against the inspection standards.

  19. Effects of alternative steeping methods on composition, antioxidant property and colour of green, black and oolong tea infusions.

    PubMed

    Lantano, Claudia; Rinaldi, Massimiliano; Cavazza, Antonella; Barbanti, Davide; Corradini, Claudio

    2015-12-01

    Cold water steeping is reported to maximise tea health benefits, but requires long infusion time. In this work, the employment of a brief hot infusion step followed by ice addition was evaluated. The comparison of this innovative method with hot and cold steeping was investigated on green, black and oolong teas. Catechins, xanthines and gallic acid content, antioxidant power, total phenolics and colour analysis were evaluated. Hot infusion shown rapid extractive power, but relevant compound degradation. On the contrary, cold infusion extracted higher level of healthy molecules with slow kinetic. The innovative method achieved in short time similar properties of cold infusion in terms of antioxidant power. As for bioactive compounds, such as gallic acid and epigallocatechin gallate, highest values, about double than in hot infusion, were recorded for green and black teas. This steeping method may represent an alternative approach for industrial beverage preparation. PMID:26604404

  20. Colour-grapheme synesthesia affects binocular vision.

    PubMed

    Paffen, Chris L E; van der Smagt, Maarten J; Nijboer, Tanja C W

    2011-01-01

    In colour-grapheme synesthesia, non-coloured graphemes are perceived as being inherently coloured. In recent years, it is debated whether visual processing of synesthesia-inducing achromatic graphemes is similar to that of chromatic graphemes. Here, we exploit the phenomenon of binocular rivalry in which incompatible images presented dichoptically compete for conscious expression. Importantly, the competition only arises if the two images are sufficiently different; if the difference between the images is small, the images will fuse into a single mixed percept. We show that achromatic digits that induce synesthetic colour percepts increase the incidence of binocular rivalry compared to achromatic non-digits that do not evoke such percepts. That is, compared to achromatically perceived non-digits, synesthesia-inducing digits increase the predominance of binocular rivalry over binocular fusion. This finding shows that the synesthetic colour experience can provide the conditions for promoting binocular rivalry, much like stimulus features that induce rivalry in normal vision.

  1. Developmental colour agnosia.

    PubMed

    van Zandvoort, Martine J E; Nijboer, Tanja C W; de Haan, Edward

    2007-08-01

    Colour agnosia concerns the inability to recognise colours despite intact colour perception, semantic memory for colour information, and colour naming. Patients with selective colour agnosia have been described and the deficit is associated with left hemisphere damage. Here we report a case study of a 43-year-old man who was referred to us with a stroke in his right cerebellar hemisphere. During the standard assessment it transpired that he was unable to name coloured patches. Detailed assessment of his colour processing showed that he suffers from a selective colour agnosia. As he claimed to have had this problem all his life, and the fact that the infratentorial infarct that he had incurred was in an area far away from the brain structures that are known to be involved in colour processing, we suggest that he is the first reported case of developmental colour agnosia.

  2. Interactions between colour and synaesthetic colour: an effect of simultaneous colour contrast on synaesthetic colours.

    PubMed

    Nijboer, Tanja C W; Gebuis, Titia; te Pas, Susan F; van der Smagt, Maarten J

    2011-01-01

    We investigated whether simultaneous colour contrast affects the synaesthetic colour experience and normal colour percept in a similar manner. We simultaneously presented a target stimulus (i.e. grapheme) and a reference stimulus (i.e. hash). Either the grapheme or the hash was presented on a saturated background of the same or opposite colour category as the synaesthetic colour and the other stimulus on a grey background. In both conditions, grapheme-colour synaesthetes were asked to colour the hash in a colour similar to the synaesthetic colour of the grapheme. Controls that were pair-matched to the synaesthetes performed the same experiment, but for them, the grapheme was presented in the colour induced by the grapheme in synaesthetes. When graphemes were presented on a grey and the hash on a coloured background, a traditional simultaneous colour-contrast effect was found for controls as well as synaesthetes. When graphemes were presented on colour and the hash on grey, the controls again showed a traditional simultaneous colour-contrast effect, whereas the synaesthetes showed the opposite effect. Our results show that synaesthetic colour experiences differ from normal colour perception; both are susceptible to different surrounding colours, but not in a comparable manner.

  3. Stamping colloidal photonic crystals: a facile way towards complex pixel colour patterns for sensing and displays.

    PubMed

    Ding, Tao; Smoukov, Stoyan K; Baumberg, Jeremy J

    2015-02-01

    Patterning of colloidal photonic crystals (CPCs) has been strongly investigated in recent years for sensing and image displays. Rather than using traditional template-directed approaches, here microimprint lithography along with convective self-assembly is applied to generate complex CPC patterns that can be adjusted to show single- or dual-colour patterns or composite CPC patterns possessing two different colours. These composite CPC patterns show different wettability with water because of the surface chemistry of the polymers and silica used. This dramatically transforms the structural colours upon liquid infiltration. By mixing different ethanol concentrations with water, the infiltration efficiency can be further improved and easily read out from changes in reflection intensity and spectral peak shifts. Integrating these nano-architectures into devices can thus yield function as image displays and as sensors for solvents.

  4. Synaesthesia and colour constancy.

    PubMed

    Erskine, Holly; Mattingley, Jason B; Arnold, Derek H

    2013-04-01

    Grapheme-colour synaesthesia is an atypical condition characterized by the perception of colours when reading achromatic text. We investigated the level of colour processing responsible for these experiences. To do so, we tapped a central characteristic of colour perception. In different lighting conditions the same wavelength of light can prompt the perception of different colours. This helps humans recognize distinctive coloured objects despite changes in illumination. We wanted to see if synaesthetic colours were generated at a neural locus that was susceptible to colour constancy analyses. We used colour matching and naming tasks to examine interactions between simulated coloured illuminants and synaesthetic colours. Neither synaesthetic colour matching or naming was impacted. This contrasted with non-synaesthetic control participants, who performed the colour-matching task with graphemes physically coloured to mimic synaesthesia. Our data suggest that synaesthetic colour signals are not generated at lower-levels of colour processing, but are introduced at higher levels of analysis and are therefore not impacted by the processes responsible for perceptual constancy.

  5. Colour Perception in ADHD

    ERIC Educational Resources Information Center

    Banaschewski, Tobias; Ruppert, Sinje; Tannock, Rosemary; Albrecht, Bjorn; Becker, Andreas; Uebel, Henrik; Sergeant, Joseph A.; Rothenberger, Aribert

    2006-01-01

    Attention-deficit/hyperactivity disorder (ADHD) is associated with unexplained impairments on speeded naming of coloured stimuli. These deficits may reflect hypofunctioning retinal dopaminergic mechanisms impairing particularly blue-yellow colour discrimination. Colour perception and rapid colour naming ability were investigated in 14 children…

  6. Single shot white light interference microscopy with colour fringe analysis for quantitative phase imaging of biological cells

    NASA Astrophysics Data System (ADS)

    Srivastava, Vishal; Mehta, D. S.

    2013-02-01

    To quantitatively obtain the phase map of Onion and human red blood cell (RBC) from white light interferogram we used Hilbert transform color fringe analysis technique. The three Red, Blue and Green color components are decomposed from single white light interferogram and Refractive index profile for Red, Blue and Green colour were computed in a completely non-invasive manner for Onion and human RBC. The present technique might be useful for non-invasive determination of the refractive index variation within cells and tissues and morphological features of sample with ease of operation and low cost.

  7. Massive star formation in Wolf-Rayet galaxies. IV. Colours, chemical-composition analysis and metallicity-luminosity relations

    NASA Astrophysics Data System (ADS)

    López-Sánchez, Á. R.; Esteban, C.

    2010-07-01

    Aims: We have performed a comprehensive multiwavelength analysis of a sample of 20 starburst galaxies that show a substantial population of very young massive stars, most of them classified as Wolf-Rayet (WR) galaxies. In this paper, the forth of the series, we present the global analysis of the derived photometric and chemical properties. Methods: We compare optical/NIR colours and the physical properties (reddening coefficient, equivalent widths of the emission and underlying absorption lines, ionization degree, electron density, and electron temperature) and chemical properties (oxygen abundances and N/O, S/O, Ne/O, Ar/O, and Fe/O ratios) with previous observations and galaxy evolution models. We compile 41 independent star-forming regions - with oxygen abundances between 12 + log(O/H) = 7.58 and 8.75 - , of which 31 have a direct estimate of the electron temperature of the ionized gas. Results: According to their absolute B-magnitude, many of them are not dwarf galaxies, but they should be during their quiescent phase. We found that both c(Hβ) and Wabs increase with increasing metallicity. The differences in the N/O ratio is explained assuming differences in the star formation histories. We detected a high N/O ratio in objects showing strong WR features (HCG 31 AC, UM 420, IRAS 0828+2816, III Zw 107, ESO 566-8 and NGC 5253). The ejecta of the WR stars may be the origin of the N enrichment in these galaxies. We compared the abundances provided by the direct method with those obtained through empirical calibrations, finding that (i) the Pilyugin method is the best suited empirical calibration for these star-forming galaxies; (ii) the relations provided by Pettini & Pagel (2004, MNRAS, 348, 59) give acceptable results for objects with 12 + log(O/H) > 8.0; and (iii) the results provided by empirical calibrations based on photoionization models are systematically 0.2-0.3 dex higher than the values derived from the direct method. The O and N abundances and the N

  8. Effects of dietary oregano and garlic essential oils on carcass characteristics, meat composition, colour, pH and sensory quality of broiler meat.

    PubMed

    Kirkpinar, F; Ünlü, H B; Serdaroğlu, M; Turp, G Y

    2014-01-01

    1. An experiment was conducted to determine the individual and combined effects of two essential oils, oregano and garlic, on carcass characteristics, meat composition, colour, pH and sensory quality of broiler meat. 2. The diets were supplemented with no essential oil (control), oregano essential oil or garlic essential oil at 300 mg/kg and oregano essential oil at 150 mg/kg + garlic essential oil at 150 mg/kg. 3. Dietary oregano and garlic oil supplementation did not affect carcass yields, the relative weight of carcass parts, breast and thigh meat composition, pH or b* value of breast meat. Oregano + garlic oil supplementation significantly decreased the L* value. The a* value of breast meat in birds given a diet supplemented with oregano oil was lower than that in birds given a diet supplemented with garlic oil and oregano oil + garlic oil. The essential oil addition had no positive effect on the oxidative stability. There was no difference between the treatments in breast appearance. 4. The juiciness, flavour, oxidised flavour and acceptability of breast meat samples were affected by treatments.

  9. Rethinking Colour Constancy.

    PubMed

    Logvinenko, Alexander D; Funt, Brian; Mirzaei, Hamidreza; Tokunaga, Rumi

    2015-01-01

    Colour constancy needs to be reconsidered in light of the limits imposed by metamer mismatching. Metamer mismatching refers to the fact that two objects reflecting metameric light under one illumination may reflect non-metameric light under a second; so two objects appearing as having the same colour under one illuminant can appear as having different colours under a second. Yet since Helmholtz, object colour has generally been believed to remain relatively constant. The deviations from colour constancy registered in experiments are usually thought to be small enough that they do not contradict the notion of colour constancy. However, it is important to determine how the deviations from colour constancy relate to the limits metamer mismatching imposes on constancy. Hence, we calculated metamer mismatching's effect for the 20 Munsell papers and 8 pairs of illuminants employed in the colour constancy study by Logvinenko and Tokunaga and found it to be so extensive that the two notions-metamer mismatching and colour constancy-must be mutually exclusive. In particular, the notion of colour constancy leads to some paradoxical phenomena such as the possibility of 20 objects having the same colour under chromatic light dispersing into a hue circle of colours under neutral light. Thus, colour constancy refers to a phenomenon, which because of metamer mismatching, simply cannot exist. Moreover, it obscures the really important visual phenomenon; namely, the alteration of object colours induced by illumination change. We show that colour is not an independent, intrinsic attribute of an object, but rather an attribute of an object/light pair, and then define a concept of material colour in terms of equivalence classes of such object/light pairs. We suggest that studying the shift in material colour under a change in illuminant will be more fruitful than pursuing colour constancy's false premise that colour is an intrinsic attribute of an object.

  10. Rethinking Colour Constancy

    PubMed Central

    Logvinenko, Alexander D.; Funt, Brian; Mirzaei, Hamidreza; Tokunaga, Rumi

    2015-01-01

    Colour constancy needs to be reconsidered in light of the limits imposed by metamer mismatching. Metamer mismatching refers to the fact that two objects reflecting metameric light under one illumination may reflect non-metameric light under a second; so two objects appearing as having the same colour under one illuminant can appear as having different colours under a second. Yet since Helmholtz, object colour has generally been believed to remain relatively constant. The deviations from colour constancy registered in experiments are usually thought to be small enough that they do not contradict the notion of colour constancy. However, it is important to determine how the deviations from colour constancy relate to the limits metamer mismatching imposes on constancy. Hence, we calculated metamer mismatching’s effect for the 20 Munsell papers and 8 pairs of illuminants employed in the colour constancy study by Logvinenko and Tokunaga and found it to be so extensive that the two notions—metamer mismatching and colour constancy—must be mutually exclusive. In particular, the notion of colour constancy leads to some paradoxical phenomena such as the possibility of 20 objects having the same colour under chromatic light dispersing into a hue circle of colours under neutral light. Thus, colour constancy refers to a phenomenon, which because of metamer mismatching, simply cannot exist. Moreover, it obscures the really important visual phenomenon; namely, the alteration of object colours induced by illumination change. We show that colour is not an independent, intrinsic attribute of an object, but rather an attribute of an object/light pair, and then define a concept of material colour in terms of equivalence classes of such object/light pairs. We suggest that studying the shift in material colour under a change in illuminant will be more fruitful than pursuing colour constancy’s false premise that colour is an intrinsic attribute of an object. PMID:26356217

  11. Longitudinal left ventricular myocardial dysfunction assessed by 2D colour tissue Doppler imaging in a dog with systemic hypertension and severe arteriosclerosis.

    PubMed

    Nicolle, A P; Carlos Sampedrano, C; Fontaine, J J; Tessier-Vetzel, D; Goumi, V; Pelligand, L; Pouchelon, J-L; Chetboul, V

    2005-03-01

    A 12-year-old sexually intact male Vendee Griffon Basset was presented for acute pulmonary oedema. Severe systemic systolic arterial hypertension (SAH) was diagnosed (290 mmHg). Despite blood and abdominal ultrasound tests, the underlying cause of the systemic hypertension could not be determined, and primary SAH was therefore suspected. Conventional echocardiography showed eccentric left ventricular hypertrophy with normal fractional shortening. Despite this apparent normal systolic function, 2D colour tissue Doppler imaging (TDI) identified a marked longitudinal systolic left ventricular myocardial alteration, whereas radial function was still preserved. Three months later, the dog underwent euthanasia because of an acute episode of distal aortic thromboembolism. Necropsy revealed severe aortic and iliac arteriosclerosis. SAH related to arteriosclerosis is a common finding in humans, but has not been previously described in dogs. Moreover, its consequence on longitudinal myocardial function using TDI has never been documented before in this species.

  12. Proposal, verification and comparison of three computer image analysis methods for detection and evaluation of colour glaucomatous changes within the optic disc of a human eye retina

    NASA Astrophysics Data System (ADS)

    Pluhacek, Frantisek; Pospisil, Jaroslav

    2005-04-01

    The typical symptom of the human eye glaucoma is a rise and a progression of the bright area (named pallor area) within the retina blind spot. The image analysis manner proposed by the authors detects and suitably numerically describes the relative size of the representative pallor area in the colour digital image of the retina obtained by a suitable fundus camera connected with the computer. Three new different computer image analysis statistical methods for experimental diagnostic evaluation of the obtained characteristic data are proposed in this article: the quantile curves method, the neural net method and the probability density curves method. The quantile curves method is based on the graphical comparison of a relative representative pallor area size with its determined normal value. The neural net and probability density curves methods can automatically and objectively classify the investigated eyes in exactly defined glaucoma risk classes and diagnosed glaucoma with the rated probabilities of incorrect diagnosis determination. All mentioned methods are verified and mutually compared by their application to the large statistical sets of human retina images of various healthy and glaucomatous subjects.

  13. Colour stability of tooth-coloured restorative materials.

    PubMed

    Gaintantzopoulou, Marianna; Kakaboura, Afrodite; Vougiouklakis, Georgios

    2005-06-01

    The colour stability of the surface and in-depth (2 mm) layer of two resin composites, a laboratory second-generation resin composite and a compomer were evaluated after 24 and 360 hours of water aging under dark and UV light conditions. The influence of various polymerization techniques on color changes was also evaluated. Color differences (deltaE*) showed higher color changes under UV light exposure than under dark storage, both at 24- and 360-hour evaluations. Color changes were statistically higher at the 360-hour assessment, in both conditions of maintenance. Compomer was the least color stable of the materials tested. Additional polymerization significantly decreased the colour change of both composite resins.

  14. Glass fibres reinforced polyester composites degradation monitoring by surface analysis

    NASA Astrophysics Data System (ADS)

    Croitoru, Catalin; Patachia, Silvia; Papancea, Adina; Baltes, Liana; Tierean, Mircea

    2015-12-01

    The paper presents a novel method for quantification of the modifications that occur on the surface of different types of gel-coated glass fibre-reinforced polyester composites under artificial UV-ageing at 254 nm. The method implies the adsorption of an ionic dye, namely methylene blue, on the UV-aged composite, and computing the CIELab colour space parameters from the photographic image of the coloured composite's surface. The method significantly enhances the colour differences between the irradiated composites and the reference, in contrast with the non-coloured ones. The colour modifications that occur represent a good indicative of the surface degradation, alteration of surface hydrophily and roughness of the composite and are in good correlation with the ATR-FTIR spectroscopy and optical microscopy results. The proposed method is easier, faster and cheaper than the traditional ones.

  15. CT scanning carcases has no detrimental effect on the colour stability of M. longissimus dorsi from beef and sheep.

    PubMed

    Jose, C G; Pethick, D W; Jacob, R H; Gardner, G E

    2009-01-01

    This study investigated the effect of computerised tomography imaging (CT scan), for carcase composition determination, on the oxy/metmyoglobin ratio, hue and L(∗), a(∗) and b(∗) scores of M. longissimus dorsi from both beef and lamb. Beef and lamb M. longissimus dorsi were divided into four proportions and randomly allocated to one of the following treatments; CT 30 day aged; CT fresh; control 30 day aged; control fresh. Colour measurements were made over a 96h retail display period. CT scan had little effect on the colour of both lamb and beef across all colour parameters. There was a small negative affect observed in CT aged samples (P<0.05) for ratio, hue, a(∗) and b(∗) values, however these differences were so small that they are unlikely to impact upon the commercial shelf-life of the product. Other factors such as aging, species and vitamin E concentration play a much greater role in colour stability than CT. Aged M. longissimus dorsi clearly had a worse colour stability than the fresh packaged samples, while beef was a lot more colour stable than lamb. It appears that CT scan for the purpose of body composition determination will not have any commercially relevant impact on colour stability of both beef and lamb.

  16. All-sky Multi-colour, Multi-epoch SuperCOSMOS Sky Survey Images Now Available in the VO Through SIAP

    NASA Astrophysics Data System (ADS)

    Hambly, N. C.; Read, M. A.; Holliman, M. S.; Cross, N. J. G.; Collins, R. S.; Mann, R. G.

    2009-09-01

    This paper describes a new all-sky Simple Image Access (SIA) protocol cut-out service based on the legacy Schmidt telescope photographic surveys (epoch 1949-2000) as digitised by the now decommissioned precision plate scanning facility SuperCOSMOS. Every part of the sky is covered in BRI (typical depths B=22, R=20, I=18 with 2 arcsec resolution) with at least two epochs in R; multiple-epoch images are available in the substantial survey overlap regions. Furthermore, specialist regions have additional filter/epoch coverage, e.g. Hα and matched R exposures in the Galactic Plane, and ˜200 multi-epoch/colour images spread over ˜30 years in the ESO/SRC survey field~287 at 21^h28^m, -45° (B1950). The service has been published to the international Virtual Observatory through the WFAU publishing registry, which can be found through the IVOA Registry of Registries. URL, http://www-wfau.roe.ac.uk:8080/ssa/SSS_SIAP IVORN, ivo://wfau.roe.ac.uk/sss-siap

  17. Does Colour Preference Have a Role in Colour Term Acquisition?

    ERIC Educational Resources Information Center

    Pitchford, Nicola J.; Davis, Emma E.; Scerif, Gaia

    2009-01-01

    A developmental association exists between colour preference and emerging colour term acquisition in young children. Colour preference might influence colour term acquisition by directing attention towards or away from a particular colour, making it more or less memorable. To investigate the role that colour preference may have in the acquisition…

  18. Monitoring chemical degradation of thermally cycled glass-fibre composites using hyperspectral imaging

    NASA Astrophysics Data System (ADS)

    Papadakis, V. M.; Müller, B.; Hagenbeek, M.; Sinke, J.; Groves, R. M.

    2016-04-01

    Nowadays, the application of glass-fibre composites in light-weight structures is growing. Although mechanical characterizations of those structures are commonly performed in testing, chemical changes of materials under stresses have not yet been well documented. In the present work coupon tests and Hyperspectral Imaging (HSI) have been used to categorise possible chemical changes of glass-fibre reinforced polymers (GFRP) which are currently used in the aircraft industry. HSI is a hybrid technique that combines spectroscopy with imaging. It is able to detect chemical degradation of surfaces and has already been successfully applied in a wide range of fields including astronomy, remote sensing, cultural heritage and medical sciences. GFRP specimens were exposed to two different thermal loading conditions. One thermal loading condition was a continuous thermal exposure at 120°C for 24h, 48 h and 96h, i.e. ageing at a constant temperature. The other thermal loading condition was thermal cycling with three different numbers of cycles (4000, 8000, 12000) and two temperature ranges (0°C to 120°C and -25°C to 95°C). The effects of both conditions were measured using both HSI and interlaminar shear (ILSS) tests. No significant changes of the physical properties of the thermally cycled GFRP specimens were detected using interlaminar shear strength tests and optical microscopy. However, when using HIS, differences of the surface conditions were detected. The results showed that the different thermal loading conditions could be successfully clustered in different colours, using the HSI linear unmixing technique. Each different thermal loading condition showed a different chemical degradation level on its surface which was indicated using different colours.

  19. Galaxy And Mass Assembly (GAMA): Galaxy colour gradients versus colour, structure, and luminosity

    NASA Astrophysics Data System (ADS)

    Kennedy, Rebecca; Bamford, Steven P.; Häußler, Boris; Brough, Sarah; Holwerda, Benne; Hopkins, Andrew M.; Vika, Marina; Vulcani, Benedetta

    2016-09-01

    Using single-component fits to SDSS/UKIDSS images of galaxies in the G09 region of the GAMA survey we study radial colour gradients across the galaxy population. We use the multi-wavelength information provided by MegaMorph analysis of galaxy light profiles to calculate intrinsic colour gradients, and divide into six subsamples split by overall Sérsic index (n) and galaxy colour. We find a bimodality in the colour gradients of high- and low-n galaxies in all wavebands which varies with overall galaxy luminosity. Global trends in colour gradients therefore result from combining the contrasting behaviour of a number of different galaxy populations. The ubiquity of strong negative colour gradients supports the picture of inside-out growth through gas accretion for blue, low-n galaxies, and through dry minor mergers for red, high-n galaxies. An exception is the blue high-n population which has properties indicative of dissipative major mergers.

  20. Colour vision deficiency.

    PubMed

    Simunovic, M P

    2010-05-01

    Colour vision deficiency is one of the commonest disorders of vision and can be divided into congenital and acquired forms. Congenital colour vision deficiency affects as many as 8% of males and 0.5% of females--the difference in prevalence reflects the fact that the commonest forms of congenital colour vision deficiency are inherited in an X-linked recessive manner. Until relatively recently, our understanding of the pathophysiological basis of colour vision deficiency largely rested on behavioural data; however, modern molecular genetic techniques have helped to elucidate its mechanisms. The current management of congenital colour vision deficiency lies chiefly in appropriate counselling (including career counselling). Although visual aids may be of benefit to those with colour vision deficiency when performing certain tasks, the evidence suggests that they do not enable wearers to obtain normal colour discrimination. In the future, gene therapy remains a possibility, with animal models demonstrating amelioration following treatment.

  1. CRISPR-dCas9 and sgRNA scaffolds enable dual-colour live imaging of satellite sequences and repeat-enriched individual loci

    PubMed Central

    Fu, Yi; Rocha, Pedro P.; Luo, Vincent M.; Raviram, Ramya; Deng, Yan; Mazzoni, Esteban O.; Skok, Jane A.

    2016-01-01

    Imaging systems that allow visualization of specific loci and nuclear structures are highly relevant for investigating how organizational changes within the nucleus play a role in regulating gene expression and other cellular processes. Here we present a live imaging system for targeted detection of genomic regions. Our approach involves generating chimaeric transcripts of viral RNAs (MS2 and PP7) and single-guide RNAs (sgRNAs), which when co-expressed with a cleavage-deficient Cas9 can recruit fluorescently tagged viral RNA-binding proteins (MCP and PCP) to specific genomic sites. This allows for rapid, stable, low-background visualization of target loci. We demonstrate the efficiency and flexibility of our method by simultaneously labelling major and minor satellite regions as well as two individual loci on mouse chromosome 12. This system provides a tool for dual-colour labelling, which is important for tracking the dynamics of chromatin interactions and for validating epigenetic processes identified in fixed cells. PMID:27222091

  2. CRISPR-dCas9 and sgRNA scaffolds enable dual-colour live imaging of satellite sequences and repeat-enriched individual loci.

    PubMed

    Fu, Yi; Rocha, Pedro P; Luo, Vincent M; Raviram, Ramya; Deng, Yan; Mazzoni, Esteban O; Skok, Jane A

    2016-01-01

    Imaging systems that allow visualization of specific loci and nuclear structures are highly relevant for investigating how organizational changes within the nucleus play a role in regulating gene expression and other cellular processes. Here we present a live imaging system for targeted detection of genomic regions. Our approach involves generating chimaeric transcripts of viral RNAs (MS2 and PP7) and single-guide RNAs (sgRNAs), which when co-expressed with a cleavage-deficient Cas9 can recruit fluorescently tagged viral RNA-binding proteins (MCP and PCP) to specific genomic sites. This allows for rapid, stable, low-background visualization of target loci. We demonstrate the efficiency and flexibility of our method by simultaneously labelling major and minor satellite regions as well as two individual loci on mouse chromosome 12. This system provides a tool for dual-colour labelling, which is important for tracking the dynamics of chromatin interactions and for validating epigenetic processes identified in fixed cells. PMID:27222091

  3. Methods, compositions and kits for imaging cells and tissues using nanoparticles and spatial frequency heterodyne imaging

    DOEpatents

    Rose-Petruck, Christoph; Wands, Jack R.; Rand, Danielle; Derdak, Zoltan; Ortiz, Vivian

    2016-04-19

    Methods, compositions, systems, devices and kits are provided herein for preparing and using a nanoparticle composition and spatial frequency heterodyne imaging for visualizing cells or tissues. In various embodiments, the nanoparticle composition includes at least one of: a nanoparticle, a polymer layer, and a binding agent, such that the polymer layer coats the nanoparticle and is for example a polyethylene glycol, a polyelectrolyte, an anionic polymer, or a cationic polymer, and such that the binding agent that specifically binds the cells or the tissue. Methods, compositions, systems, devices and kits are provided for identifying potential therapeutic agents in a model using the nanoparticle composition and spatial frequency heterodyne imaging.

  4. Colour assortative pairing in a colour polymorphic lizard is independent of population morph diversity.

    PubMed

    Pérez I de Lanuza, Guillem; Font, Enrique; Carretero, Miguel Ángel

    2016-10-01

    Previous work with a colour polymorphic population of Podarcis muralis (Lacertidae) revealed that lizards pair by ventral colour, favouring the same colour (i.e. homomorphic) pairs. Such assortative pairing, which probably results in colour assortative mating, can have consequences for the genetic structure of the population and potentially promote speciation. The population previously studied, located in the Pyrenees, encompasses white, yellow and orange animals, as well as intermediate white-orange and yellow-orange morphs. However, other Pyrenean populations of P. muralis have less ventral colour morphs. Our aim in this study is to test the generality of the assortative colour pairing system, extending our previous analyses to populations with different morph compositions and frequencies. The results show that the assortative pattern of pairing is similar in all the populations analysed and, hence, independent of morph composition and not restricted to pentamorphic populations. This suggests that assortative pairing by colour is a general phenomenon for colour polymorphic populations of P. muralis. PMID:27649703

  5. Colour harmony of two colour combinations in clothes matching

    NASA Astrophysics Data System (ADS)

    Wicaksono, Sungging Haryo; Fu, Tzu-Hao; Chen, Liang-Ya; Hou, Chien-Yu; Ou, Li-Chen

    2015-01-01

    There are many definitions and theories about colour harmony. But no consistent rules and definitions can be determined. Some previous researches show that there are many factors that influence the colour harmony. Colour harmony is highly depends on the external factors, including the context of colour besides their colour combinations. In the current research an experiment conducted by observing two colour combinations which applied in shirt and trousers. Twenty observers involved in the experiment, consist of ten male and ten female. Each observer predict colour harmony score in 58 samples of shirt and trouser pairs, the colour combination then applied upside down. Based on the experimental results, male and female group has similar tendency in colour harmony score prediction in the same colour samples (correlation coefficient, r=0.84). Upside down colour combinations will change the impression of observer about colour harmony and yields a different value of colour harmony prediction score which indicated from correlation coefficient results of 0.53.

  6. High-throughput dual-colour precision imaging for brain-wide connectome with cytoarchitectonic landmarks at the cellular level

    PubMed Central

    Gong, Hui; Xu, Dongli; Yuan, Jing; Li, Xiangning; Guo, Congdi; Peng, Jie; Li, Yuxin; Schwarz, Lindsay A.; Li, Anan; Hu, Bihe; Xiong, Benyi; Sun, Qingtao; Zhang, Yalun; Liu, Jiepeng; Zhong, Qiuyuan; Xu, Tonghui; Zeng, Shaoqun; Luo, Qingming

    2016-01-01

    The precise annotation and accurate identification of neural structures are prerequisites for studying mammalian brain function. The orientation of neurons and neural circuits is usually determined by mapping brain images to coarse axial-sampling planar reference atlases. However, individual differences at the cellular level likely lead to position errors and an inability to orient neural projections at single-cell resolution. Here, we present a high-throughput precision imaging method that can acquire a co-localized brain-wide data set of both fluorescent-labelled neurons and counterstained cell bodies at a voxel size of 0.32 × 0.32 × 2.0 μm in 3 days for a single mouse brain. We acquire mouse whole-brain imaging data sets of multiple types of neurons and projections with anatomical annotation at single-neuron resolution. The results show that the simultaneous acquisition of labelled neural structures and cytoarchitecture reference in the same brain greatly facilitates precise tracing of long-range projections and accurate locating of nuclei. PMID:27374071

  7. Measurement of the Nucleus Area and Nucleus/Cytoplasm and Mitochondria/Nucleus Ratios in Human Colon Tissues by Dual-Colour Two-Photon Microscopy Imaging

    PubMed Central

    Su Lim, Chang; Sun Kim, Eun; Yeon Kim, Ji; Taek Hong, Seung; Jai Chun, Hoon; Eun Kang, Dong; Rae Cho, Bong

    2015-01-01

    We developed two-photon (TP) probes for DNA (ABI-Nu), cytoplasm (Pyr-CT), and mitochondria (BF-MT). We found that ABI-Nu binds to AT in the minor groove, while ABI-Nu and BF-MT are effective for tracking in the cytoplasm and mitochondria, respectively. These probes showed very large effective two-photon action cross section values of 2230, 1555, and 790 Göppert-Mayer units (1 GM  =  10−50 cm4 s photon−1molecule−1) at 740 nm with emission maxima at 473, 561, and 560 nm, respectively, in each organelle. Using these probes, we quantitatively estimated the mean nuclear area and the ratios of nuclei to cytoplasm and mitochondria to nuclei in human colon tissues by dual-colour two-photon microscopy imaging within 2  h after biopsy. The mean nuclear area and the nuclei to cytoplasm and mitochondria to cytoplasm ratios increased in the following order: normal colon mucosa

  8. The North Sea: Satellite colour atlas

    NASA Astrophysics Data System (ADS)

    Holligan, P. M.; Aarup, T.; Groom, S. B.

    Satellite imagery of the North Sea from the Coastal Zone Color Scanner (CZCS) shows complex seasonal changes in the optical and biological properties of surface waters, features which have not been resolved, hitherto, through direct observations from ships. Selected scenes for the period 1979-1986, presented as single band (channel 3), colour composite (channels 1 + 2 + 3) and chlorophyll (channels 1/3 or 2/3) images, are used to demonstrate the relative surface distributions between February and October of suspended sediments, coccolithophores and plant pigments. Comparison are made also with sea surface temperature images from the Advanced Very High Resolution Radiometer (AVHRR). Quantitative evaluation of the CZCS data is restricted by a lack of contemporary in situ optical and biological measurements. However, chlorophyll and Secchi disc distributions, determined by measurements from research ships have been compared qualitatively with images from the Southern Bight (13 May 1986) and for the east central North Sea (24 August 1984 and 24 October 1985). Mini series of CZCS images are presented to show the annual coccolithophore blooms, the development of the spring bloom in the Skagerrak, June 1983 and summer chlorophyl distributions in the German Bight.

  9. From spectral information to animal colour vision: experiments and concepts

    PubMed Central

    Kelber, Almut; Osorio, Daniel

    2010-01-01

    Many animals use the spectral distribution of light to guide behaviour, but whether they have colour vision has been debated for over a century. Our strong subjective experience of colour and the fact that human vision is the paradigm for colour science inevitably raises the question of how we compare with other species. This article outlines four grades of ‘colour vision’ that can be related to the behavioural uses of spectral information, and perhaps to the underlying mechanisms. In the first, even without an (image-forming) eye, simple organisms can compare photoreceptor signals to locate a desired light environment. At the next grade, chromatic mechanisms along with spatial vision guide innate preferences for objects such as food or mates; this is sometimes described as wavelength-specific behaviour. Here, we compare the capabilities of di- and trichromatic vision, and ask why some animals have more than three spectral types of receptors. Behaviours guided by innate preferences are then distinguished from a grade that allows learning, in part because the ability to learn an arbitrary colour is evidence for a neural representation of colour. The fourth grade concerns colour appearance rather than colour difference: for instance, the distinction between hue and saturation, and colour categorization. These higher-level phenomena are essential to human colour perception but poorly known in animals, and we suggest how they can be studied. Finally, we observe that awareness of colour and colour qualia cannot be easily tested in animals. PMID:20164101

  10. From spectral information to animal colour vision: experiments and concepts.

    PubMed

    Kelber, Almut; Osorio, Daniel

    2010-06-01

    Many animals use the spectral distribution of light to guide behaviour, but whether they have colour vision has been debated for over a century. Our strong subjective experience of colour and the fact that human vision is the paradigm for colour science inevitably raises the question of how we compare with other species. This article outlines four grades of 'colour vision' that can be related to the behavioural uses of spectral information, and perhaps to the underlying mechanisms. In the first, even without an (image-forming) eye, simple organisms can compare photoreceptor signals to locate a desired light environment. At the next grade, chromatic mechanisms along with spatial vision guide innate preferences for objects such as food or mates; this is sometimes described as wavelength-specific behaviour. Here, we compare the capabilities of di- and trichromatic vision, and ask why some animals have more than three spectral types of receptors. Behaviours guided by innate preferences are then distinguished from a grade that allows learning, in part because the ability to learn an arbitrary colour is evidence for a neural representation of colour. The fourth grade concerns colour appearance rather than colour difference: for instance, the distinction between hue and saturation, and colour categorization. These higher-level phenomena are essential to human colour perception but poorly known in animals, and we suggest how they can be studied. Finally, we observe that awareness of colour and colour qualia cannot be easily tested in animals. PMID:20164101

  11. Composite pseudocolor images: a technique to enhance the visual correlation between ventilation-perfusion lung images

    NASA Astrophysics Data System (ADS)

    Vaz de Carvalho, Carlos; Costa, Antonio A.; Seixas, M.; Ferreira, F. N.; Guedes, M. A.; Amaral, I.

    1993-07-01

    Lung ventilation and perfusion raw nuclear medicine images obtained from a gamma camera can be difficult to analyze on a per si basis. A method to optimize the visual correlation between these images was established through the use of new combination images: Composite Pseudo-Color (CPC) images. The major topic of this study is the assessment of the usefulness of this method in the detection of lung malfunction.

  12. Comment on 'Aerosol and Rayleigh radiance contributions to Coastal Zone Colour Scanner images' by Eckstein and Simpson

    NASA Technical Reports Server (NTRS)

    Gordon, H. R.; Evans, R. H.

    1993-01-01

    In a recent paper Eckstein and Simpson describe what they believe to be serious difficulties and/or errors with the CZCS (Coastal Zone Color Scanner) processing algorithms based on their analysis of seven images. Here we point out that portions of their analysis, particularly those dealing with multiple scattered Rayleigh radiance, are incorrect. We also argue that other problems they discuss have already been addressed in the literature. Finally, we suggest that many apparent artifacts in CZCS-derived pigment fields are likely to be due to inadequacies in the sensor band set or to poor radiometric stability, both of which will be remedied with the next generation of ocean color sensors.

  13. Compositional breast imaging using a dual-energy mammography protocol

    SciTech Connect

    Laidevant, Aurelie D.; Malkov, Serghei; Flowers, Chris I.; Kerlikowske, Karla; Shepherd, John A.

    2010-01-15

    Purpose: Mammography has a low sensitivity in dense breasts due to low contrast between malignant and normal tissue confounded by the predominant water density of the breast. Water is found in both adipose and fibroglandular tissue and constitutes most of the mass of a breast. However, significant protein mass is mainly found in the fibroglandular tissue where most cancers originate. If the protein compartment in a mammogram could be imaged without the influence of water, the sensitivity and specificity of the mammogram may be improved. This article describes a novel approach to dual-energy mammography, full-field digital compositional mammography (FFDCM), which can independently image the three compositional components of breast tissue: water, lipid, and protein. Methods: Dual-energy attenuation and breast shape measures are used together to solve for the three compositional thicknesses. Dual-energy measurements were performed on breast-mimicking phantoms using a full-field digital mammography unit. The phantoms were made of materials shown to have similar x-ray attenuation properties of the compositional compartments. They were made of two main stacks of thicknesses around 2 and 4 cm. Twenty-six thickness and composition combinations were used to derive the compositional calibration using a least-squares fitting approach. Results: Very high accuracy was achieved with a simple cubic fitting function with root mean square errors of 0.023, 0.011, and 0.012 cm for the water, lipid, and protein thicknesses, respectively. The repeatability (percent coefficient of variation) of these measures was tested using sequential images and was found to be 0.5%, 0.5%, and 3.3% for water, lipid, and protein, respectively. However, swapping the location of the two stacks of the phantom on the imaging plate introduced further errors showing the need for more complete system uniformity corrections. Finally, a preliminary breast image is presented of each of the compositional

  14. Magnetic resonance imaging of gel-cast ceramic composites

    SciTech Connect

    Dieckman, S.L.; Balss, K.M.; Waterfield, L.G.

    1997-04-01

    Magnetic resonance imaging (MRI) techniques are being employed to aid in the development of advanced near-net-shape gel-cast ceramic composites. MRI is a unique nondestructive evaluation tool that provides information on both the chemical and physical properties of materials. In this effort, MRI imaging was performed to monitor the drying of porous green-state alumina - methacrylamide-N.N`-methylene bisacrylamide (MAM-MBAM) polymerized composite specimens. Studies were performed on several specimens as a function of humidity and time. The mass and shrinkage of the specimens were also monitored and correlated with the water content.

  15. Magnetic Resonance Imaging of Gel-cast Ceramic Composites

    DOE R&D Accomplishments Database

    Dieckman, S. L.; Balss, K. M.; Waterfield, L. G.; Jendrzejczyk, J. A.; Raptis, A. C.

    1997-01-16

    Magnetic resonance imaging (MRI) techniques are being employed to aid in the development of advanced near-net-shape gel-cast ceramic composites. MRI is a unique nondestructive evaluation tool that provides information on both the chemical and physical properties of materials. In this effort, MRI imaging was performed to monitor the drying of porous green-state alumina - methacrylamide-N.N`-methylene bisacrylamide (MAM-MBAM) polymerized composite specimens. Studies were performed on several specimens as a function of humidity and time. The mass and shrinkage of the specimens were also monitored and correlated with the water content.

  16. Pitfalls in colour photography of choroidal tumours

    PubMed Central

    Schalenbourg, A; Zografos, L

    2013-01-01

    Colour imaging of fundus tumours has been transformed by the development of digital and confocal scanning laser photography. These advances provide numerous benefits, such as panoramic images, increased contrast, non-contact wide-angle imaging, non-mydriatic photography, and simultaneous angiography. False tumour colour representation can, however, cause serious diagnostic errors. Large choroidal tumours can be totally invisible on angiography. Pseudogrowth can occur because of artefacts caused by different methods of fundus illumination, movement of reference blood vessels, and flattening of Bruch's membrane and sclera when tumour regression occurs. Awareness of these pitfalls should prevent the clinician from misdiagnosing tumours and wrongfully concluding that a tumour has grown. PMID:23238442

  17. Pitfalls in colour photography of choroidal tumours.

    PubMed

    Schalenbourg, A; Zografos, L

    2013-02-01

    Colour imaging of fundus tumours has been transformed by the development of digital and confocal scanning laser photography. These advances provide numerous benefits, such as panoramic images, increased contrast, non-contact wide-angle imaging, non-mydriatic photography, and simultaneous angiography. False tumour colour representation can, however, cause serious diagnostic errors. Large choroidal tumours can be totally invisible on angiography. Pseudogrowth can occur because of artefacts caused by different methods of fundus illumination, movement of reference blood vessels, and flattening of Bruch's membrane and sclera when tumour regression occurs. Awareness of these pitfalls should prevent the clinician from misdiagnosing tumours and wrongfully concluding that a tumour has grown.

  18. Three-dimensional plasmonic stereoscopic prints in full colour

    NASA Astrophysics Data System (ADS)

    Goh, Xiao Ming; Zheng, Yihan; Tan, Shawn J.; Zhang, Lei; Kumar, Karthik; Qiu, Cheng-Wei; Yang, Joel K. W.

    2014-11-01

    Metal nanostructures can be designed to scatter different colours depending on the polarization of the incident light. Such spectral control is attractive for applications such as high-density optical storage, but challenges remain in creating microprints with a single-layer architecture that simultaneously enables full-spectral and polarization control of the scattered light. Here we demonstrate independently tunable biaxial colour pixels composed of isolated nanoellipses or nanosquare dimers that can exhibit a full range of colours in reflection mode with linear polarization dependence. Effective polarization-sensitive full-colour prints are realized. With this, we encoded two colour images within the same area and further use this to achieve depth perception by realizing three-dimensional stereoscopic colour microprint. Coupled with the low cost and durability of aluminium as the functional material in our pixel design, such polarization-sensitive encoding can realize a wide spectrum of applications in colour displays, data storage and anti-counterfeiting technologies.

  19. Three-dimensional plasmonic stereoscopic prints in full colour.

    PubMed

    Goh, Xiao Ming; Zheng, Yihan; Tan, Shawn J; Zhang, Lei; Kumar, Karthik; Qiu, Cheng-Wei; Yang, Joel K W

    2014-11-04

    Metal nanostructures can be designed to scatter different colours depending on the polarization of the incident light. Such spectral control is attractive for applications such as high-density optical storage, but challenges remain in creating microprints with a single-layer architecture that simultaneously enables full-spectral and polarization control of the scattered light. Here we demonstrate independently tunable biaxial colour pixels composed of isolated nanoellipses or nanosquare dimers that can exhibit a full range of colours in reflection mode with linear polarization dependence. Effective polarization-sensitive full-colour prints are realized. With this, we encoded two colour images within the same area and further use this to achieve depth perception by realizing three-dimensional stereoscopic colour microprint. Coupled with the low cost and durability of aluminium as the functional material in our pixel design, such polarization-sensitive encoding can realize a wide spectrum of applications in colour displays, data storage and anti-counterfeiting technologies.

  20. Field-portable pixel super-resolution colour microscope.

    PubMed

    Greenbaum, Alon; Akbari, Najva; Feizi, Alborz; Luo, Wei; Ozcan, Aydogan

    2013-01-01

    Based on partially-coherent digital in-line holography, we report a field-portable microscope that can render lensfree colour images over a wide field-of-view of e.g., >20 mm(2). This computational holographic microscope weighs less than 145 grams with dimensions smaller than 17×6×5 cm, making it especially suitable for field settings and point-of-care use. In this lensfree imaging design, we merged a colorization algorithm with a source shifting based multi-height pixel super-resolution technique to mitigate 'rainbow' like colour artefacts that are typical in holographic imaging. This image processing scheme is based on transforming the colour components of an RGB image into YUV colour space, which separates colour information from brightness component of an image. The resolution of our super-resolution colour microscope was characterized using a USAF test chart to confirm sub-micron spatial resolution, even for reconstructions that employ multi-height phase recovery to handle dense and connected objects. To further demonstrate the performance of this colour microscope Papanicolaou (Pap) smears were also successfully imaged. This field-portable and wide-field computational colour microscope could be useful for tele-medicine applications in resource poor settings.

  1. Uropygial gland and bib colouration in the house sparrow

    PubMed Central

    2016-01-01

    Birds frequently signal different qualities by plumage colouration, mainly during mating. However, plumage colouration is determined during the moult, and therefore it would indicate the quality of individual birds during the moult, not its current quality. Recent studies, however, suggest that birds could modify plumage colouration by using cosmetic preen oil produced by the uropygial gland. In this study, I show that bib colouration is related to uropygial gland size and body condition in male house sparrows (Passer domesticus). Moreover, I conducted an experiment in which a group of sparrows were inoculated with an antigen, mimicking an illness. In control birds, short-term changes in bib colouration were related to both body condition and change in uropygial gland size. Therefore, birds that reduced uropygial gland size showed a greater colouration change. However, bib colouration did not change with the change in uropygial gland size in experimental birds inoculated with the antigen. Given that the experiment did not affect preen oil production or consumption, this finding tentatively suggests that the immune challenge provoked a change in the composition of preen oil, affecting its cosmetic properties. In short, the results of this study suggest that (1) male house sparrows produce cosmetic preen oil that alters the colouration of their bibs; (2) the more change in uropygial gland size, the more change in bib colouration; and (3) in this way, bib colouration has the potential to signal current health status, since less healthy birds showed less capacity to change bib colouration. PMID:27280079

  2. Uropygial gland and bib colouration in the house sparrow.

    PubMed

    Moreno-Rueda, Gregorio

    2016-01-01

    Birds frequently signal different qualities by plumage colouration, mainly during mating. However, plumage colouration is determined during the moult, and therefore it would indicate the quality of individual birds during the moult, not its current quality. Recent studies, however, suggest that birds could modify plumage colouration by using cosmetic preen oil produced by the uropygial gland. In this study, I show that bib colouration is related to uropygial gland size and body condition in male house sparrows (Passer domesticus). Moreover, I conducted an experiment in which a group of sparrows were inoculated with an antigen, mimicking an illness. In control birds, short-term changes in bib colouration were related to both body condition and change in uropygial gland size. Therefore, birds that reduced uropygial gland size showed a greater colouration change. However, bib colouration did not change with the change in uropygial gland size in experimental birds inoculated with the antigen. Given that the experiment did not affect preen oil production or consumption, this finding tentatively suggests that the immune challenge provoked a change in the composition of preen oil, affecting its cosmetic properties. In short, the results of this study suggest that (1) male house sparrows produce cosmetic preen oil that alters the colouration of their bibs; (2) the more change in uropygial gland size, the more change in bib colouration; and (3) in this way, bib colouration has the potential to signal current health status, since less healthy birds showed less capacity to change bib colouration.

  3. Uropygial gland and bib colouration in the house sparrow.

    PubMed

    Moreno-Rueda, Gregorio

    2016-01-01

    Birds frequently signal different qualities by plumage colouration, mainly during mating. However, plumage colouration is determined during the moult, and therefore it would indicate the quality of individual birds during the moult, not its current quality. Recent studies, however, suggest that birds could modify plumage colouration by using cosmetic preen oil produced by the uropygial gland. In this study, I show that bib colouration is related to uropygial gland size and body condition in male house sparrows (Passer domesticus). Moreover, I conducted an experiment in which a group of sparrows were inoculated with an antigen, mimicking an illness. In control birds, short-term changes in bib colouration were related to both body condition and change in uropygial gland size. Therefore, birds that reduced uropygial gland size showed a greater colouration change. However, bib colouration did not change with the change in uropygial gland size in experimental birds inoculated with the antigen. Given that the experiment did not affect preen oil production or consumption, this finding tentatively suggests that the immune challenge provoked a change in the composition of preen oil, affecting its cosmetic properties. In short, the results of this study suggest that (1) male house sparrows produce cosmetic preen oil that alters the colouration of their bibs; (2) the more change in uropygial gland size, the more change in bib colouration; and (3) in this way, bib colouration has the potential to signal current health status, since less healthy birds showed less capacity to change bib colouration. PMID:27280079

  4. Document Image Processing: Going beyond the Black-and-White Barrier. Progress, Issues and Options with Greyscale and Colour Image Processing.

    ERIC Educational Resources Information Center

    Hendley, Tom

    1995-01-01

    Discussion of digital document image processing focuses on issues and options associated with greyscale and color image processing. Topics include speed; size of original document; scanning resolution; markets for different categories of scanners, including photographic libraries, publishing, and office applications; hybrid systems; data…

  5. Mining histopathological images via composite hashing and online learning.

    PubMed

    Zhang, Xiaofan; Yang, Lin; Liu, Wei; Su, Hai; Zhang, Shaoting

    2014-01-01

    With a continuous growing amount of annotated histopathological images, large-scale and data-driven methods potentially provide the promise of bridging the semantic gap between these images and their diagnoses. The purpose of this paper is to increase the scale at which automated systems can entail scalable analysis of histopathological images in massive databases. Specifically, we propose a principled framework to unify hashing-based image retrieval and supervised learning. Concretely, composite hashing is designed to simultaneously fuse and compress multiple high-dimensional image features into tens of binary hash bits, enabling scalable image retrieval with a very low computational cost. Upon a local data subset that retains the retrieved images, supervised learning methods are applied on-the-fly to model image structures for accurate classification. Our framework is validated thoroughly on 1120 lung microscopic tissue images by differentiating adenocarcinoma and squamous carcinoma. The average accuracy as 87.5% with only 17ms running time, which compares favorably with other commonly used methods. PMID:25485414

  6. Mining histopathological images via composite hashing and online learning.

    PubMed

    Zhang, Xiaofan; Yang, Lin; Liu, Wei; Su, Hai; Zhang, Shaoting

    2014-01-01

    With a continuous growing amount of annotated histopathological images, large-scale and data-driven methods potentially provide the promise of bridging the semantic gap between these images and their diagnoses. The purpose of this paper is to increase the scale at which automated systems can entail scalable analysis of histopathological images in massive databases. Specifically, we propose a principled framework to unify hashing-based image retrieval and supervised learning. Concretely, composite hashing is designed to simultaneously fuse and compress multiple high-dimensional image features into tens of binary hash bits, enabling scalable image retrieval with a very low computational cost. Upon a local data subset that retains the retrieved images, supervised learning methods are applied on-the-fly to model image structures for accurate classification. Our framework is validated thoroughly on 1120 lung microscopic tissue images by differentiating adenocarcinoma and squamous carcinoma. The average accuracy as 87.5% with only 17ms running time, which compares favorably with other commonly used methods.

  7. Adaptive colouration in amphibians.

    PubMed

    Rudh, Andreas; Qvarnström, Anna

    2013-01-01

    Amphibians, i.e. salamanders, frogs and caecilians show a wide range of bright colours in combination with contrasting patterns. There is variation among species, populations and also within species and populations. Furthermore, individuals often change colours during developmental stages or in response to environmental factors. This extraordinary variation means that there are excellent opportunities to test hypotheses of the adaptive significance of colours using amphibian species as models. We review the present view of functions of colouration in amphibians with the main focus on relatively unexplored topics. Variation in colouration has been found to play a role in thermoregulation, UV protection, predator avoidance and sexual signalling. However, many proposed cases of adaptive functions of colouration in amphibians remain virtually scientifically unexplored and surprisingly few genes influencing pigmentation or patterning have been detected. We would like to especially encourage more studies that take advantage of recent developments in measurement of visual properties of several possible signalling receivers (e.g. predators, competitors or mates). Future investigations on interactions between behaviour, ecology and vision have the potential to challenge our current view of the adaptive function of colouration in amphibians.

  8. Unconventional colour vision.

    PubMed

    Marshall, Justin; Arikawa, Kentaro

    2014-12-15

    Butterflies and stomatopods are certainly outliers in their unconventional colour sense and despite some similarities at first glance, in fact sample the world of colour very differently. In one way, butterflies are relatively conventional, possessing either tri-or tetrachromatic colour vision, then just adding one or several task-specific sub-mechanisms onto this. It is the stomatopods so far that have really pushed the boat out into a different colour vision mechanism. Over 400 million years of independent evolution they have arrived at a solution with more in common with the way a satellite sensor examines the colours of the earth than other animals. Remember, however, that unconventional colour vision is not just the realm of the serially polychromatic. Apparently waterfleas with four classes of spectral receptors living in ponds operate a task-specific spectral sense with no need, or indeed neural processing power, to construct a complex discriminatory mechanism. It seems they have the butterfly added-extra set without the more complex comparative chromatic mechanisms, although in truth, conclusive behavioural proof is lacking. Behavioural observation of colour vision in the ecological context of each animal is vital before making the distinction between conventional and unconventional. Just counting spectral sensitivities is never enough.

  9. Adaptive colouration in amphibians.

    PubMed

    Rudh, Andreas; Qvarnström, Anna

    2013-01-01

    Amphibians, i.e. salamanders, frogs and caecilians show a wide range of bright colours in combination with contrasting patterns. There is variation among species, populations and also within species and populations. Furthermore, individuals often change colours during developmental stages or in response to environmental factors. This extraordinary variation means that there are excellent opportunities to test hypotheses of the adaptive significance of colours using amphibian species as models. We review the present view of functions of colouration in amphibians with the main focus on relatively unexplored topics. Variation in colouration has been found to play a role in thermoregulation, UV protection, predator avoidance and sexual signalling. However, many proposed cases of adaptive functions of colouration in amphibians remain virtually scientifically unexplored and surprisingly few genes influencing pigmentation or patterning have been detected. We would like to especially encourage more studies that take advantage of recent developments in measurement of visual properties of several possible signalling receivers (e.g. predators, competitors or mates). Future investigations on interactions between behaviour, ecology and vision have the potential to challenge our current view of the adaptive function of colouration in amphibians. PMID:23664831

  10. Colour-coded echographic flow imaging and spectral analysis of cerebrospinal fluid (CSF). Part III. In-vitro study of low flow velocity detection related to decreasing particle concentration (hematocrit) and tube lumen.

    PubMed

    Winkler, P; Helmke, K

    1992-01-01

    An in-vitro steady flow system was designed to determine the lowest flow velocities that can be detected by echographic colour flow imaging and spectral analysis. The flow detection level was determined hydrostatically by reducing the fluid level to below the point at which a flow signal was visible, then increasing the height until the colour flow reappeared. This was confirmed in all instances by spectral analysis. The height (angle-corrected velocity) of the spectral envelope was also determined. Mean volume flow was then obtained by using a graduated cylinder and a stop watch. The lowest hematocrit detectable was identified using a stepwise dilution of packed human red blood cells with 0.9% sodium chloride. Three different PVC-tubes with inner diameters of 2.1 mm, 1.1 mm and 0.51 mm were used.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1594308

  11. Object knowledge modulates colour appearance

    PubMed Central

    Witzel, Christoph; Valkova, Hanna; Hansen, Thorsten; Gegenfurtner, Karl R

    2011-01-01

    We investigated the memory colour effect for colour diagnostic artificial objects. Since knowledge about these objects and their colours has been learned in everyday life, these stimuli allow the investigation of the influence of acquired object knowledge on colour appearance. These investigations are relevant for questions about how object and colour information in high-level vision interact as well as for research about the influence of learning and experience on perception in general. In order to identify suitable artificial objects, we developed a reaction time paradigm that measures (subjective) colour diagnosticity. In the main experiment, participants adjusted sixteen such objects to their typical colour as well as to grey. If the achromatic object appears in its typical colour, then participants should adjust it to the opponent colour in order to subjectively perceive it as grey. We found that knowledge about the typical colour influences the colour appearance of artificial objects. This effect was particularly strong along the daylight axis. PMID:23145224

  12. Spatial composition of US images using probabilistic weighted means

    NASA Astrophysics Data System (ADS)

    Perez-Gonzalez, J. L.; Arámbula Cosío, Fernando; Medina-Bañuelos, V.

    2015-12-01

    Ultrasound (US) images of the fetal brain provide the experts with valuable indicators of the fetal development. However as the skull thickens, it obstructs the transmission of the acoustic waves, which in turn occludes the anatomy behind the thickened fetal skull. A viable option to improve the visibility of the fetal brain, before complete calcification of the skull, is the calculation of a compounded image made of different views of the same anatomical plane. In this work we report a new method for the composition of ultrasound images based on the Weighted Mean of the pixels, from different views, which correspond to each position (x, y) in the final compounded image. A support vector machine (SVM) is used to calculate the weights of each pixel from a different view, based on intensity, entropy and variance features. We present the initial test results of our method on synthetic US images of a head phantom, contaminated with speckle noise; we report the signal to noise ratio (SNR) and the normalized mutual information (NMI), for different number of views (2, 3, and 5), and compare the results against images compounded using the Mean, Root Mean Square (RMS), and Geometrical Mean composition methods. With our scheme we were able to recover the occluded information to increase the NMI from 16% to 26%, representing a 58% improvement.

  13. The effect of terebinth (Pistacia terebinthus L.) coffee addition on the chemical and physical characteristics, colour values, organic acid profiles, mineral compositions and sensory properties of ice creams.

    PubMed

    Yüksel, Arzu Kavaz; Şat, Ihsan Güngör; Yüksel, Mehmet

    2015-12-01

    The aim of this research was to evaluate the effect of terebinth (Pistacia terebinthus L.) coffee addition (0.5, 1 and 2 %) on the chemical and physical properties, colour values, organic acid profiles, mineral contents and sensory characteristics of ice creams. The total solids, fat, titratable acidity, viscosity, first dripping time and complete melting time values, a (*) and b (*) colour properties, citric, lactic, acetic and butyric acid levels and Ca, Cu, Mg, Fe, K, Zn and Na concentrations of ice creams showed an increase with the increment of terebinth coffee amount, while protein, pH, L (*), propionic acid and orotic acid values decreased. However, Al and malic acid were not detected in any of the samples. The overall acceptability scores of the sensory properties showed that the addition of 1 % terebinth coffee to the ice cream was more appreciated by the panellists.

  14. The effect of terebinth (Pistacia terebinthus L.) coffee addition on the chemical and physical characteristics, colour values, organic acid profiles, mineral compositions and sensory properties of ice creams.

    PubMed

    Yüksel, Arzu Kavaz; Şat, Ihsan Güngör; Yüksel, Mehmet

    2015-12-01

    The aim of this research was to evaluate the effect of terebinth (Pistacia terebinthus L.) coffee addition (0.5, 1 and 2 %) on the chemical and physical properties, colour values, organic acid profiles, mineral contents and sensory characteristics of ice creams. The total solids, fat, titratable acidity, viscosity, first dripping time and complete melting time values, a (*) and b (*) colour properties, citric, lactic, acetic and butyric acid levels and Ca, Cu, Mg, Fe, K, Zn and Na concentrations of ice creams showed an increase with the increment of terebinth coffee amount, while protein, pH, L (*), propionic acid and orotic acid values decreased. However, Al and malic acid were not detected in any of the samples. The overall acceptability scores of the sensory properties showed that the addition of 1 % terebinth coffee to the ice cream was more appreciated by the panellists. PMID:26604374

  15. Colour Coding of Maps for Colour Deficient Observers.

    PubMed

    Røise, Anne Kari; Kvitle, Anne Kristin; Green, Phil

    2016-01-01

    We evaluate the colour coding of a web map traffic information service based on profiles simulating colour vision deficiencies. Based on these simulations and principles for universal design, we propose adjustments of the existing colours creating more readable maps for the colour vision deficient observers. PMID:27534329

  16. Colour Coding of Maps for Colour Deficient Observers.

    PubMed

    Røise, Anne Kari; Kvitle, Anne Kristin; Green, Phil

    2016-01-01

    We evaluate the colour coding of a web map traffic information service based on profiles simulating colour vision deficiencies. Based on these simulations and principles for universal design, we propose adjustments of the existing colours creating more readable maps for the colour vision deficient observers.

  17. False-color composite image of Prince Albert, Canada

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a false color composite of Prince Albert, Canada, centered at 53.91 north latitude and 104.69 west longitude. This image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on the 20th orbit of the Shuttle Endeavour. The area is located 40 km north and 30 km east of the town of Prince Albert in the Saskatchewan province of Canada. The image covers the area east of the Candle Lake, between gravel surface highways 120 and 106 and west of 106. The area in the middle of the image covers the entire Nipawin (Narrow Hills) provincial park. The look angle of the radar is 30 degrees and the size of the image is approximately 20 kilometers by 50 kilometers (12 by 30 miles). Most of the dark areas in the image are the ice-covered lakes in the region. The dark area on the top right corner of the image is the White Gull Lake north of the intersection of Highway 120 and 913. The right middle part of the image shows Lake Ispuchaw and Lower Fishing Lake

  18. Optimality of the basic colour categories for classification

    PubMed Central

    Griffin, Lewis D

    2005-01-01

    Categorization of colour has been widely studied as a window into human language and cognition, and quite separately has been used pragmatically in image-database retrieval systems. This suggests the hypothesis that the best category system for pragmatic purposes coincides with human categories (i.e. the basic colours). We have tested this hypothesis by assessing the performance of different category systems in a machine-vision task. The task was the identification of the odd-one-out from triples of images obtained using a web-based image-search service. In each triple, two of the images had been retrieved using the same search term, the other a different term. The terms were simple concrete nouns. The results were as follows: (i) the odd-one-out task can be performed better than chance using colour alone; (ii) basic colour categorization performs better than random systems of categories; (iii) a category system that performs better than the basic colours could not be found; and (iv) it is not just the general layout of the basic colours that is important, but also the detail. We conclude that (i) the results support the plausibility of an explanation for the basic colours as a result of a pressure-to-optimality and (ii) the basic colours are good categories for machine vision image-retrieval systems. PMID:16849219

  19. False-color composite image of Raco, Michigan

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This image is a false color composite of Raco, Michigan, centered at 46.39 north latitude and 84.88 east longitude. This image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on the 20th orbit of the Shuttle Endeavour. The area shown is approximately 20 kilometers by 50 kilometers. Raco is located at the eastern end of Michigan's upper peninsula, west of Sault Ste. Marie and south of Whitefish Bay on Lake Superior. In this color representation, darker areas in the image are smooth surfaces such as frozen lakes and other non-forested areas. The colors are related to the types of trees and the brightness is related to the amount of plant material covering the surface, called forest biomass. The Jet Propulsion Laboratory alternative photo number is P-43882.

  20. The many colours of 'the dress'.

    PubMed

    Gegenfurtner, Karl R; Bloj, Marina; Toscani, Matteo

    2015-06-29

    There has been an intense discussion among the public about the colour of a dress, shown in a picture posted originally on Tumblr (http://swiked.tumblr.com/post/112073818575/guys-please-help-me-is-this-dress-white-and; accessed on 10:56 am GMT on Tue 24 Mar 2015). Some people argue that they see a white dress with golden lace, while others describe the dress as blue with black lace. Here we show that the question "what colour is the dress?" has more than two answers. In fact, there is a continuum of colour percepts across different observers. We measured colour matches on a calibrated screen for two groups of observers who had reported different percepts of the dress. Surprisingly, differences between the two groups arose mainly from differences in lightness, rather than chromaticity of the colours they adjusted to match the dress. We speculate that the ambiguity arises in the case of this particular image because the distribution of colours within the dress closely matches the distribution of natural daylights. This makes it more difficult to disambiguate illumination changes from those in reflectance. PMID:25981790

  1. Colour Mixing Based on Daylight

    ERIC Educational Resources Information Center

    Meyn, Jan-Peter

    2008-01-01

    Colour science is based on the sensation of monochromatic light. In contrast to that, surface colours are caused by reflection of wide sections of the daylight spectrum. Non-spectral colours like magenta and purple appear homologous to colours with spectral hue, if the approach of mixing monochromatic light is abandoned. It is shown that a large…

  2. Rockpool Gobies Change Colour for Camouflage

    PubMed Central

    Stevens, Martin; Lown, Alice E.; Denton, Alexander M.

    2014-01-01

    Camouflage is found in a wide range of species living in numerous habitat types, offering protection from visually guided predators. This includes many species from the intertidal zone, which must cope with background types diverse in appearance and with multiple predator groups foraging at high and low tide. Many animals are capable of either relatively slow (hours, days, weeks) or rapid (seconds and minutes) colour change in order to better resemble the background against which they are found, but most work has been restricted to a few species or taxa. It is often suggested that many small intertidal fish are capable of colour change for camouflage, yet little experimental work has addressed this. Here, we test rock gobies (Gobius paganellus) for colour change abilities, and whether they can tune their appearance to match the background. In two experiments, we place gobies on backgrounds of different brightness (black or white), and of different colours (red and blue) and use digital image analysis and modelling of predator (avian) vision to quantify colour and luminance (perceived lightness) changes and camouflage. We find that gobies are capable of rapid colour change (occurring within one minute), and that they can change their luminance on lighter or darker backgrounds. When presented on backgrounds of different colours, gobies also change their colour (hue and saturation) while keeping luminance the same. These changes lead to predicted improvements in camouflage match to the background. Our study shows that small rockpool fish are capable of rapid visual change for concealment, and that this may be an important mechanism in many species to avoid predation, especially in complex heterogeneous environments. PMID:25333382

  3. Plasmonic colour laser printing.

    PubMed

    Zhu, Xiaolong; Vannahme, Christoph; Højlund-Nielsen, Emil; Mortensen, N Asger; Kristensen, Anders

    2016-04-01

    Colour generation by plasmonic nanostructures and metasurfaces has several advantages over dye technology: reduced pixel area, sub-wavelength resolution and the production of bright and non-fading colours. However, plasmonic colour patterns need to be pre-designed and printed either by e-beam lithography (EBL) or focused ion beam (FIB), both expensive and not scalable processes that are not suitable for post-processing customization. Here we show a method of colour printing on nanoimprinted plasmonic metasurfaces using laser post-writing. Laser pulses induce transient local heat generation that leads to melting and reshaping of the imprinted nanostructures. Depending on the laser pulse energy density, different surface morphologies that support different plasmonic resonances leading to different colour appearances can be created. Using this technique we can print all primary colours with a speed of 1 ns per pixel, resolution up to 127,000 dots per inch (DPI) and power consumption down to 0.3 nJ per pixel. PMID:26657786

  4. Plasmonic colour laser printing

    NASA Astrophysics Data System (ADS)

    Zhu, Xiaolong; Vannahme, Christoph; Højlund-Nielsen, Emil; Mortensen, N. Asger; Kristensen, Anders

    2016-04-01

    Colour generation by plasmonic nanostructures and metasurfaces has several advantages over dye technology: reduced pixel area, sub-wavelength resolution and the production of bright and non-fading colours. However, plasmonic colour patterns need to be pre-designed and printed either by e-beam lithography (EBL) or focused ion beam (FIB), both expensive and not scalable processes that are not suitable for post-processing customization. Here we show a method of colour printing on nanoimprinted plasmonic metasurfaces using laser post-writing. Laser pulses induce transient local heat generation that leads to melting and reshaping of the imprinted nanostructures. Depending on the laser pulse energy density, different surface morphologies that support different plasmonic resonances leading to different colour appearances can be created. Using this technique we can print all primary colours with a speed of 1 ns per pixel, resolution up to 127,000 dots per inch (DPI) and power consumption down to 0.3 nJ per pixel.

  5. IRIS COLOUR CLASSIFICATION SCALES--THEN AND NOW.

    PubMed

    Grigore, Mariana; Avram, Alina

    2015-01-01

    Eye colour is one of the most obvious phenotypic traits of an individual. Since the first documented classification scale developed in 1843, there have been numerous attempts to classify the iris colour. In the past centuries, iris colour classification scales has had various colour categories and mostly relied on comparison of an individual's eye with painted glass eyes. Once photography techniques were refined, standard iris photographs replaced painted eyes, but this did not solve the problem of painted/ printed colour variability in time. Early clinical scales were easy to use, but lacked objectivity and were not standardised or statistically tested for reproducibility. The era of automated iris colour classification systems came with the technological development. Spectrophotometry, digital analysis of high-resolution iris images, hyper spectral analysis of the human real iris and the dedicated iris colour analysis software, all accomplished an objective, accurate iris colour classification, but are quite expensive and limited in use to research environment. Iris colour classification systems evolved continuously due to their use in a wide range of studies, especially in the fields of anthropology, epidemiology and genetics. Despite the wide range of the existing scales, up until present there has been no generally accepted iris colour classification scale.

  6. Structure recognition from high resolution images of ceramic composites

    SciTech Connect

    Ushizima, Daniela; Perciano, Talita; Krishnan, Harinarayan; Loring, Burlen; Bale, Hrishikesh; Parkinson, Dilworth; Sethian, James

    2015-01-05

    Fibers provide exceptional strength-to-weight ratio capabilities when woven into ceramic composites, transforming them into materials with exceptional resistance to high temperature, and high strength combined with improved fracture toughness. Microcracks are inevitable when the material is under strain, which can be imaged using synchrotron X-ray computed micro-tomography (mu-CT) for assessment of material mechanical toughness variation. An important part of this analysis is to recognize fibrillar features. This paper presents algorithms for detecting and quantifying composite cracks and fiber breaks from high-resolution image stacks. First, we propose recognition algorithms to identify the different structures of the composite, including matrix cracks and fibers breaks. Second, we introduce our package F3D for fast filtering of large 3D imagery, implemented in OpenCL to take advantage of graphic cards. Results show that our algorithms automatically identify micro-damage and that the GPU-based implementation introduced here takes minutes, being 17x faster than similar tools on a typical image file.

  7. Remotely sensed image processing service composition based on heuristic search

    NASA Astrophysics Data System (ADS)

    Yang, Xiaoxia; Zhu, Qing; Li, Hai-feng; Zhao, Wen-hao

    2008-12-01

    As remote sensing technology become ever more powerful with multi-platform and multi-sensor, it has been widely recognized for contributing to geospatial information efforts. Because the remotely sensed image processing demands large-scale, collaborative processing and massive storage capabilities to satisfy the increasing demands of various applications, the effect and efficiency of the remotely sensed image processing is far from the user's expectation. The emergence of Service Oriented Architecture (SOA) may make this challenge manageable. It encapsulate all processing function into services and recombine them with service chain. The service composition on demand has become a hot topic. Aiming at the success rate, quality and efficiency of processing service composition for remote sensing application, a remote sensed image processing service composition method is proposed in this paper. It composes services for a user requirement through two steps: 1) dynamically constructs a complete service dependency graph for user requirement on-line; 2) AO* based heuristic searches for optimal valid path in service dependency graph. These services within the service dependency graph are considered relevant to the specific request, instead of overall registered services. The second step, heuristic search is a promising approach for automated planning. Starting with the initial state, AO* uses a heuristic function to select states until the user requirement is reached. Experimental results show that this method has a good performance even the repository has a large number of processing services.

  8. Low-Resolution Vehicle Image Recognition Technology by Frame-Composition of Moving Images

    NASA Astrophysics Data System (ADS)

    Kanzawa, Yusuke; Kobayashi, Hiroki; Ohkawa, Takenao; Ito, Toshio

    Developing on-board automotive driver assistance systems aiming to alert drivers about driving environments, and possible collision with other vehicles has attracted a lot of attention lately. Especially, many researchers have suggested the forward vehicle recognition technology by a camera on vehicle. In the forward vehicle recognition, however, it is difficult to detect the features of vehicle from a distant vehicle image by conventional methods because the image is too low-resolution (LR). This paper presents vehicle image recognition technology for detecting of the features of a distant vehicle by frame-composition of moving images. To detect the vehicle features of a distant LR vehicle image, we use the moving images obtained from the camera on the vehicle, and utilize super-resolution (SR) image reconstruction. SR image reconstruction is to use signal processing techniques to obtain a high-resolution (or sequence) image from observed multiple LR images. Use of this technique on real road image, we show the effectiveness of the proposed techniques.

  9. Imaging Strategies for Assessing Cartilage Composition in Osteoarthritis

    PubMed Central

    Matzat, Stephen J.; Kogan, Feliks; Fong, Grant W.; Gold, Garry E.

    2015-01-01

    Efforts to reduce the ever-increasing rates of osteoarthritis (OA) in the developed world require the ability to non-invasively detect the degradation of joint tissues before advanced damage has occurred. This is particularly relevant for damage to articular cartilage because this soft tissue lacks the capacity to repair itself following major damage and is essential to proper joint function. While conventional magnetic resonance imaging (MRI) provides sufficient contrast to visualize articular cartilage morphology, more advanced imaging strategies are necessary for understanding the underlying biochemical composition of cartilage that begins to break down in the earliest stages of OA. This review discusses the biochemical basis and the advantages and disadvantages associated with each of these techniques. Recent implementations for these techniques are touched upon, and future considerations for improving the research and clinical power of these imaging technologies are also discussed. PMID:25218737

  10. The colour of fitness: plumage coloration and lifetime reproductive success in the tawny owl

    PubMed Central

    Brommer, Jon E; Ahola, Kari; Karstinen, Teuvo

    2005-01-01

    We studied variation in plumage colour and life history in a population of tawny owls (Strix aluco) in southern Finland, using 26 years of data on individually marked male and female owls. Colour was scored on a semi-continuous scale from pale grey to reddish brown. Colour scoring was repeatable and showed a bimodal distribution (grey and brown morph) in both sexes. During the study period, colour composition was stable in the study population in both sexes. The sexes did not mate assortatively with respect to their colour. Colour was a highly heritable trait and was under selection. Grey-coloured male and female owls had a higher lifetime production of fledglings, and grey-coloured male (but not female) owls produced more recruits during their lifetime than brown individuals. Selection on colour was mediated through viability selection and not through fecundity selection. Our results reveal remarkably strong selection on a genetically determined phenotypic trait. PMID:16024349

  11. Guided wave phased array beamforming and imaging in composite plates.

    PubMed

    Yu, Lingyu; Tian, Zhenhua

    2016-05-01

    This paper describes phased array beamforming using guided waves in anisotropic composite plates. A generic phased array algorithm is presented, in which direction dependent guided wave parameters and the energy skew effect are considered. This beamforming at an angular direction is achieved based on the classic delay-and-sum principle by applying phase delays to signals received at array elements and adding up the delayed signals. The phase delays are determined with the goal to maximize the array output at the desired direction and minimize it otherwise. For array characterization, the beam pattern of rectangular grid arrays in composite plates is derived. In addition to the beam pattern, the beamforming factor in terms of wavenumber distribution is defined to provide intrinsic explanations for phased array beamforming. The beamforming and damage detection in a composite plate are demonstrated using rectangular grid arrays made by a non-contact scanning laser Doppler vibrometer. Detection images of the composite plate with multiple surface defects at various directions are obtained. The results show that the guided wave phased array method is a potential effective method for rapid inspection of large composite structures.

  12. Temporal full-colour tuning through non-steady-state upconversion

    NASA Astrophysics Data System (ADS)

    Deng, Renren; Qin, Fei; Chen, Runfeng; Huang, Wei; Hong, Minghui; Liu, Xiaogang

    2015-03-01

    Developing light-harvesting materials with tunable emission colours has always been at the forefront of colour display technologies. The variation in materials composition, phase and structure can provide a useful tool for producing a wide range of emission colours, but controlling the colour gamut in a material with a fixed composition remains a daunting challenge. Here, we demonstrate a convenient, versatile approach to dynamically fine-tuning emission in the full colour range from a new class of core-shell upconversion nanocrystals by adjusting the pulse width of infrared laser beams. Our mechanistic investigations suggest that the unprecedented colour tunability from these nanocrystals is governed by a non-steady-state upconversion process. These findings provide keen insights into controlling energy transfer in out-of-equilibrium optical processes, while offering the possibility for the construction of true three-dimensional, full-colour display systems with high spatial resolution and locally addressable colour gamut.

  13. Colour in flux: describing and printing colour in art

    NASA Astrophysics Data System (ADS)

    Parraman, Carinna

    2008-01-01

    This presentation will describe artists, practitioners and scientists, who were interested in developing a deeper psychological, emotional and practical understanding of the human visual system who were working with wavelength, paint and other materials. From a selection of prints at The Prints and Drawings Department at Tate London, the presentation will refer to artists who were motivated by issues relating to how colour pigment was mixed and printed, to interrogate and explain colour perception and colour science, and in art, how artists have used colour to challenge the viewer and how a viewer might describe their experience of colour. The title Colour in Flux refers, not only to the perceptual effect of the juxtaposition of one colour pigment with another, but also to the changes and challenges for the print industry. In the light of screenprinted examples from the 60s and 70s, the presentation will discuss 21 st century ideas on colour and how these notions have informed the Centre for Fine Print Research's (CFPR) practical research in colour printing. The latter part of this presentation will discuss the implications for the need to change methods in mixing inks that moves away from existing colour spaces, from non intuitive colour mixing to bespoke ink sets, colour mixing approaches and colour mixing methods that are not reliant on RGB or CMYK.

  14. 2-Colour photolithography.

    PubMed

    Fourkas, John T; Petersen, John S

    2014-05-21

    Photolithography is a crucial technology for both research and industry. The desire to be able to create ever finer features has fuelled a push towards lithographic methods that use electromagnetic radiation or charged particles with the shortest possible wavelength. At the same time, the physics and chemistry involved in employing light or particles with short wavelengths present great challenges. A new class of approaches to photolithography on the nanoscale involves the use of photoresists that can be activated with one colour of visible or near-ultraviolet light and deactivated with a second colour. Such methods hold the promise of attaining lithographic resolution that rivals or even exceeds that currently sought by industry, while at the same time using wavelengths of light that are inexpensive to produce and can be manipulated readily. The physical chemistry of 2-colour photolithography is a rich area of science that is only now beginning to be explored.

  15. Genetic analyses of the human eye colours using a novel objective method for eye colour classification.

    PubMed

    Andersen, Jeppe D; Johansen, Peter; Harder, Stine; Christoffersen, Susanne R; Delgado, Mikaela C; Henriksen, Sarah T; Nielsen, Mette M; Sørensen, Erik; Ullum, Henrik; Hansen, Thomas; Dahl, Anders L; Paulsen, Rasmus R; Børsting, Claus; Morling, Niels

    2013-09-01

    In this study, we present a new objective method for measuring the eye colour on a continuous scale that allows researchers to associate genetic markers with different shades of eye colour. With the use of the custom designed software Digital Iris Analysis Tool (DIAT), the iris was automatically identified and extracted from high resolution digital images. DIAT was made user friendly with a graphical user interface. The software counted the number of blue and brown pixels in the iris image and calculated a Pixel Index of the Eye (PIE-score) that described the eye colour quantitatively. The PIE-score ranged from -1 to 1 (brown to blue). The software eliminated the need for user based interpretation and qualitative eye colour categories. In 94% (570) of 605 analyzed eye images, the iris region was successfully extracted and a PIE-score was calculated. A very high correlation between the PIE-score and the human perception of eye colour was observed. The correlations between the PIE-scores and the six IrisPlex SNPs (HERC2 rs12913832, OCA2 rs1800407, SLC24A4 rs12896399, TYR rs1393350, SLC45A2 rs16891982 and IRF4 rs12203592) were analyzed in 570 individuals. Significant differences (p<10(-6)) in the PIE-scores of the individuals typed as HERC2 rs12913832 G (PIE=0.99) and rs12913832 GA (PIE=-0.71) or A (PIE=-0.87) were observed. We adjusted for the effect of HERC2 rs12913832 and showed that the quantitative PIE-scores were significantly associated with SNPs with minor effects (OCA2 rs1800407, SLC24A4 rs12896399 and TYR rs1393350) on the eye colour. We evaluated the two published prediction models for eye colour (IrisPlex [1] and Snipper[2]) and compared the predictions with the PIE-scores. We found good concordance with the prediction from individuals typed as HERC2 rs12913832 G. However, both methods had difficulties in categorizing individuals typed as HERC2 rs12913832 GA because of the large variation in eye colour in HERC2 rs12913832 GA individuals. With the use of

  16. Flower Colour: How Bumblebees Handle Colours with Perceptually Changing Hues.

    PubMed

    Lunau, Klaus

    2016-03-21

    Colours are floral signals enabling bees to detect, inspect and discriminate flowers in a multitasking world. Behavioural tests now show that trained bumblebees find iridescent coloured targets more quickly and that weak iridescence does not corrupt target identification. PMID:27003883

  17. Flower Colour: How Bumblebees Handle Colours with Perceptually Changing Hues.

    PubMed

    Lunau, Klaus

    2016-03-21

    Colours are floral signals enabling bees to detect, inspect and discriminate flowers in a multitasking world. Behavioural tests now show that trained bumblebees find iridescent coloured targets more quickly and that weak iridescence does not corrupt target identification.

  18. Why birds eat colourful grit: colour preferences revealed by the colour of gizzard stones.

    PubMed

    Møller, A P; Erritzøe, J

    2010-03-01

    Colour preferences from sexual or social contexts are assumed to have arisen owing to preferences for specific kinds of food, representing a sensory bias, but once colour preferences have evolved in a sexual context, they may also be expressed during foraging. We tested whether preferences for specific body colours (i.e. plumage and soft parts) were related to colour preferences for grit ingested by birds. Birds eat grit to facilitate break down of food by the gizzard, and this function is independent of the colour of grit, but depends on the physical properties of stones. Bird species were significantly consistent in colour of grit, and grit of different colours varied in prevalence among species, even when analyses were restricted to a sample from a single locality. There were positive correlations between presence of lilac and red grit in the gizzard and presence of sexually dichromatic lilac and red colour on the body. There was a positive correlation between red grit colour and red sexually monochromatic body colour. Bird species with many different sexual colours, but not sexually monochromatic colours on their body had many different colours of grit. Males had more lilac and red grit than females, with this effect differing among species, whereas that was not the case for grit of other colours. These findings are consistent with the sensory bias hypothesis that birds express preferences for grit of specific colours and a high diversity of colours related to sexual colouration of the body, even when the colour of such grit is only visible to the individual at the moment of ingestion.

  19. Characterization of fiber composite flywheels by ultrasonic imaging techniques

    SciTech Connect

    Tsao, M.C.; Grills, R.H.; Andrew, G.A.; Coppa, A.P.

    1983-01-01

    A set of flywheels of different fiber composites has been investigated ultrasonically by an ULTRA IMAGE III System developed by General Dynamics. The 40 cm (16 in.) in diameter and 4.3 cm (1.7 in.) thick flywheels have been studied in an immersion test with a 2.5 cm (1 in.) diameter, 1.5 MHz, conically focused transducer. By monitoring the amplitude of the back surface signals from the wheels and displaying the amplitude variations with different color bands, the internal structures of the wheels such as the fiber orientations and bonding distributions can be examined in detail. The baseline information concerning the integrity of these prototype flywheels, relative to different manufacturing processes, with and without ring shrink fit, has been recorded. This paper describes a consistent, reliance, and cost-effective nondestructive testing technique for analyzing the internal bonding structures of fiber composites.

  20. Spatio-temporal colour correction of strongly degraded movies

    NASA Astrophysics Data System (ADS)

    Islam, A. B. M. Tariqul; Farup, Ivar

    2011-01-01

    The archives of motion pictures represent an important part of precious cultural heritage. Unfortunately, these cinematography collections are vulnerable to different distortions such as colour fading which is beyond the capability of photochemical restoration process. Spatial colour algorithms-Retinex and ACE provide helpful tool in restoring strongly degraded colour films but, there are some challenges associated with these algorithms. We present an automatic colour correction technique for digital colour restoration of strongly degraded movie material. The method is based upon the existing STRESS algorithm. In order to cope with the problem of highly correlated colour channels, we implemented a preprocessing step in which saturation enhancement is performed in a PCA space. Spatial colour algorithms tend to emphasize all details in the images, including dust and scratches. Surprisingly, we found that the presence of these defects does not affect the behaviour of the colour correction algorithm. Although the STRESS algorithm is already in itself more efficient than traditional spatial colour algorithms, it is still computationally expensive. To speed it up further, we went beyond the spatial domain of the frames and extended the algorithm to the temporal domain. This way, we were able to achieve an 80 percent reduction of the computational time compared to processing every single frame individually. We performed two user experiments and found that the visual quality of the resulting frames was significantly better than with existing methods. Thus, our method outperforms the existing ones in terms of both visual quality and computational efficiency.

  1. Ultrasonic scanning system for imaging flaw growth in composites

    NASA Technical Reports Server (NTRS)

    Kiraly, L. J.; Meyn, E. H.

    1982-01-01

    A system for measuring and visually representing damage in composite specimens while they are being loaded was demonstrated. It uses a hobbiest grade microcomputer system to control data taking and image processing. The system scans operator selected regions of the specimen while it is under load in a tensile test machine and measures internal damage by the attenuation of a 2.5 MHz ultrasonic beam passed through the specimen. The microcomputer dynamically controls the position of ultrasonic transducers mounted on a two axis motor driven carriage. As many as 65,536 samples can be taken and filed on a floppy disk system in less than four minutes.

  2. Taylor Impact Tests on PBX Composites: Imaging and Analysis

    NASA Astrophysics Data System (ADS)

    Thompson, Darla; Deluca, Racci

    2013-06-01

    A series of Taylor impact tests were performed on three plastic bonded explosive (PBX) formulations: PBX 9501, PBXN-9 and HPP (propellant). The first two formulations are HMX-based, and all three have been characterized quasi-statically in tension and compression. The Taylor impact tests use a 500 psi gas gun to launch PBX projectiles (approximately 30 grams, 16 mm diameter, 76 mm long) at velocities as high as 215 m/s. Tests were performed remotely and no sign of ignition/reaction have been observed to date. High-speed imaging was used to capture the impact of the specimen onto the surface of a steel anvil. Side-view contour images have been analyzed using dynamic stress equations from the literature, and additionally, front-view images have been used to estimate a tensile strain failure criterion for initial specimen fracture. Post-test sieve analysis of specimen debris correlates fragmentation with projectile velocity, and these data show interesting differences between composites. Along with other quasi-static and dynamic measurements, these impact images and fragmentation data provide a useful metric for the calibration or evaluation of intermediate-rate model predictions of PBX constituitive response and failure/fragmentation. Intermediate-rate tests involving other impact configurations are being considered.

  3. Taylor impact tests on PBX composites: imaging and analysis

    NASA Astrophysics Data System (ADS)

    Graff Thompson, Daria; DeLuca, Racci; Archuleta, Jose; Brown, Geoff W.; Koby, Joseph

    2014-05-01

    A series of Taylor impact tests were performed on three plastic bonded explosive (PBX) formulations: PBX 9501, PBXN-9 and HPP (propellant). The first two formulations are HMX-based, and all three have been characterized quasi-statically in tension and compression. The Taylor impact tests use a 500 psi gas gun to launch PBX projectiles (approximately 30 grams, 16 mm diameter, 76 mm long), velocities as high as 215 m/s, at a steel anvil. Tests were performed remotely and no sign of ignition/reaction have been observed to date. Highspeed imaging was used to capture the impact of the specimen onto anvil surface. Side-view contour images have been analyzed using dynamic stress equations from the literature, and additionally, front-view images have been used to estimate a tensile strain failure criterion for initial specimen fracture. Post-test sieve analysis of specimen debris correlates fragmentation with projectile velocity, and these data show interesting differences between composites. Along with other quasi-static and dynamic measurements, Taylor impact images and fragmentation data provide a useful metric for the calibration or evaluation of intermediate-rate model predictions of PBX constituitive response and failure/fragmentation. Intermediate-rate tests involving other impact configurations are being considered.

  4. Fun with Colour

    ERIC Educational Resources Information Center

    Rennie, Richard

    2015-01-01

    The Australian Curriculum: Science for Year 5 includes "recognising that the colour of an object depends on the properties of the object and the color of the light source". This article shows how much more can be done with color in the science laboratory. Activities include using a prism to explore white light, using a hand lens to…

  5. Colour vision in billfish.

    PubMed Central

    Fritsches, K A; Partridge, J C; Pettigrew, J D; Marshall, N J

    2000-01-01

    Members of the billfish family are highly visual predatory teleosts inhabiting the open ocean. Little is known about their visual abilities in detail, but past studies have indicated that these fishes were likely to be monochromats. This study, however, presents evidence of two anatomically distinct cone types in billfish. The cells are arranged in a regular mosaic pattern of single and twin cones as in many fishes, and this arrangement suggests that the different cone types also show different spectral sensitivity, which is the basis for colour vision. First measurements using microspectrophotometry (MSP) revealed a peak absorption of the rod pigment at 484 nm, indicating that MSP, despite technical difficulties, will be a decisive tool in proving colour vision in these offshore fishes. When hunting, billfish such as the sailfish flash bright blue bars on their sides. This colour reflects largely in ultraviolet (UV) light at 350 nm as revealed by spectrophotometric measurements. Billfish lenses block light of wavelengths below 400 nm, presumably rendering the animal blind to the UV component of its own body colour. Interestingly, at least two prey species of billfish have lenses transmitting light in the UV waveband and are therefore likely to perceive a large fraction of the UV peak found in the blue bar of the sailfish. The possible biological significance of this finding is discussed. PMID:11079409

  6. Colour, vision and ergonomics.

    PubMed

    Pinheiro, Cristina; da Silva, Fernando Moreira

    2012-01-01

    This paper is based on a research project - Visual Communication and Inclusive Design-Colour, Legibility and Aged Vision, developed at the Faculty of Architecture of Lisbon. The research has the aim of determining specific design principles to be applied to visual communication design (printed) objects, in order to be easily read and perceived by all. This study target group was composed by a selection of socially active individuals, between 55 and 80 years, and we used cultural events posters as objects of study and observation. The main objective is to overlap the study of areas such as colour, vision, older people's colour vision, ergonomics, chromatic contrasts, typography and legibility. In the end we will produce a manual with guidelines and information to apply scientific knowledge into the communication design projectual practice. Within the normal aging process, visual functions gradually decline; the quality of vision worsens, colour vision and contrast sensitivity are also affected. As people's needs change along with age, design should help people and communities, and improve life quality in the present. Applying principles of visually accessible design and ergonomics, the printed design objects, (or interior spaces, urban environments, products, signage and all kinds of visually information) will be effective, easier on everyone's eyes not only for visually impaired people but also for all of us as we age.

  7. Damage Assessment of Composite Structures Using Digital Image Correlation

    NASA Astrophysics Data System (ADS)

    Caminero, M. A.; Lopez-Pedrosa, M.; Pinna, C.; Soutis, C.

    2014-02-01

    The steady increase of Carbon-Fiber Reinforced Polymer (CFRP) Structures in modern aircraft will reach a new dimension with the entry into service of the Boeing 787 and Airbus 350. Replacement of damaged parts will not be a preferable solution due to the high level of integration and the large size of the components involved. Consequently the need to develop repair techniques and processes for composite components is readily apparent. Bonded patch repair technologies provide an alternative to mechanically fastened repairs with significantly higher performance, especially for relatively thin skins. Carefully designed adhesively bonded patches can lead to cost effective and highly efficient repairs in comparison with conventional riveted patch repairs that cut fibers and introduce highly strained regions. In this work, the assessment of the damage process taking place in notched (open-hole) specimens under uniaxial tensile loading was studied. Two-dimensional (2D) and three-dimensional (3D) Digital Image Correlation (DIC) techniques were employed to obtain full-field surface strain measurements in carbon-fiber/epoxy T700/M21 composite plates with different stacking sequences in the presence of an open circular hole. Penetrant enhanced X-ray radiographs were taken to identify damage location and extent after loading around the hole. DIC strain fields were compared to finite element predictions. In addition, DIC techniques were used to characterise damage and performance of adhesively bonded patch repairs in composite panels under tensile loading. This part of work relates to strength/stiffness restoration of damaged composite aircraft that becomes more important as composites are used more extensively in the construction of modern jet airliners. The behaviour of bonded patches under loading was monitored using DIC full-field strain measurements. Location and extent of damage identified by X-ray radiography correlates well with DIC strain results giving confidence to

  8. Determining chemical composition of materials through micro-CT images.

    PubMed

    Jussiani, Eduardo Inocente; Dos Reis, Paulo José; Appoloni, Carlos Roberto

    2016-10-01

    X-ray microtomography is a 3D non-destructive method which, through digital images, enables a view of the internal structure of samples. Recently, researchers have been extensively performing various methods in the attempt to determine the chemical composition of materials. This paper brings further insight into this matter and proposes a new experimental method for determining the internal chemical composition of samples. Using a set of standard samples, calibration curves can be created that allow to relate the average gray scale of a sample obtained through microtomographic images to the value of ρZeff(m). In this model, ρZeff(m) is the parameter that chemically characterizes a material. The exponent m is obtained by the average value obtained with standard samples, which were titanium dioxide (TiO2), calcium chloride (CaCl2), calcium hydroxide (Ca(OH)2), and calcium nitrate (Ca(NO3)2). For the samples scanning process, a Bruker SkyScan 1172 microCT was used for testing rocks, nylon, graphite, calcium carbonate (CaCO3) and aluminum samples. The experimental results achieved by this method were consistent with the theoretical values. PMID:27451140

  9. Reducing scalloping in synthetic aperture radar images using a composite image transform

    NASA Astrophysics Data System (ADS)

    Landmark, Knut; Solberg, Anne H. S.

    2015-10-01

    In burst mode SAR imaging, echo intensity depends on the target's azimuth position in the antenna pattern. As a result, an amplitude modulation known as scalloping may appear, particularly in ScanSAR images of ocean areas. A denoising method, recently developed for multibeam bathymetry, can be used to reduce residual scalloping in ScanSAR images. The algorithm is analogous to a band-stop filter in the frequency domain. Here, the transform is the composition of an edge detection operator and a discrete Radon transform (DRT). The edge operator accentuates fine-scale intensity changes; the DRT focuses linear features, as each DRT component is the sum of pixel intensities along a linear graph. A descalloping filter is implemented in the DRT domain by suppressing the range direction. The restored image is obtained by applying the inverse composite transform. First, a rapidly converging iterative pseudo-inverse DRT is computed. The edge operator is a spatial filter based on a discrete approximation of the Laplace operator, but modified to make the operator invertible. The method was tested on ocean scene ScanSAR images from the Envisat Advanced Synthetic Aperture Radar. The scalloping effect was significantly reduced, with no apparent distortion or smoothing of physical features.

  10. Colour thresholding and objective quantification in bioimaging

    NASA Technical Reports Server (NTRS)

    Fermin, C. D.; Gerber, M. A.; Torre-Bueno, J. R.

    1992-01-01

    Computer imaging is rapidly becoming an indispensable tool for the quantification of variables in research and medicine. Whilst its use in medicine has largely been limited to qualitative observations, imaging in applied basic sciences, medical research and biotechnology demands objective quantification of the variables in question. In black and white densitometry (0-256 levels of intensity) the separation of subtle differences between closely related hues from stains is sometimes very difficult. True-colour and real-time video microscopy analysis offer choices not previously available with monochrome systems. In this paper we demonstrate the usefulness of colour thresholding, which has so far proven indispensable for proper objective quantification of the products of histochemical reactions and/or subtle differences in tissue and cells. In addition, we provide interested, but untrained readers with basic information that may assist decisions regarding the most suitable set-up for a project under consideration. Data from projects in progress at Tulane are shown to illustrate the advantage of colour thresholding over monochrome densitometry and for objective quantification of subtle colour differences between experimental and control samples.

  11. Coloured marking inside glass by laser radiation

    NASA Astrophysics Data System (ADS)

    Ligbado, Grace; Horn, Alexander; Kreutz, Ernst W.; Krauss, Manfred M.; Siedow, Norbert; Hensel, Hartmut

    2005-11-01

    Laser labelling inside glass induces micro-cracks by high energy densities in the focus. The micro-cracks reduce the mechanical stability of glass. Light scattering allows the observer to perceive the cracks as white pixels. Coloured marking of glass in this manner is not possible. Coloured marking inside glass by changing the oxidation state of the metal ions locally in the focus does not weaken the mechanical properties of the glass. Two kind of glass systems, lime-natron-silicate and borosilicate with 0.5 % mass-content of doping are investigated. The simultaneous presence of donators and acceptors allows a transition of electrons between polyvalent ions, and can lead to permanent colour-centres inside the glass, due to the fact that the absorption of the polyvalent ions is changed by the laser-induced conversion process. For this purpose a 3 ω Nd:YAG (wavelength λL = 355 nm, pulse duration t = 10 to 80 ns) and a Ti:Sapphire solid-state laser (wavelength λL = 810 nm, pulse duration t = 200 fs) are used. The radiation parameters and the chemical composition of the glass (mainly doping) are the dominant factors to generate coloured marking. The transmittance as a function of the fluence and the change of the absorption coefficient is measured and gives a statement of the colourshade. Further the difference between lime-natron-silicate and borosilicate glass (same doping variety) is examined. Actually mauve, yellow, red-brown an grey colouring can be produced. Cracks in the microstructure of glass can also be the cause for brown colour-centres generating.

  12. Measuring the colour of rendering mortars

    NASA Astrophysics Data System (ADS)

    Govaerts, Yves; Meulebroeck, Wendy; Verdonck, Ann; de Bouw, Michael

    2014-05-01

    When restoring decorative mortar layers on historic façades, professionals need to determine the colour of these finishes in order to select an appropriate repair mortar. Currently, the appearance of these renders is only assessed from a subjective point of view. To match with the aesthetic aspects of the façade, contractors must constantly adjust their repair mortar composition to avoid a patchwork of different colours, which is detrimental for heritage. This time-consuming (trial-and-error) methodology can be excluded by evaluating `colour' with an objective numerical approach. The challenge of the research was to define and evaluate optimal material dependent boundary conditions for measuring the colour of nonhomogeneous mortars. Four samples with different scale of heterogeneity were measured by two spectrocolorimeters, both with a diffuse illumination geometry. The results were plotted in CIE-L*a*b* colour space. By calculating the colour difference (ΔE*), the influence of measuring with or without specular component was evaluated. We discovered the minimal number of measuring points depends on the scale of heterogeneity and the aperture area. The less homogeneous the mortar sample is and the smaller the aperture area, the more unique measuring points are required. Therefore, it is recommended to choose an aperture head of 25 mm or more to reduce the number of measurements, making your work time-efficient. However, in order to obtain accurate measurements on site, a portable optical spectrum analyser can be used with a 6 mm-diameter aperture, a viewing angle of 10°, SCI mode, illumination source D65, considering a minimum of 15 unique measuring points.

  13. Evolution of vertebrate colour vision.

    PubMed

    Jacobs, Gerald H; Rowe, Mickey P

    2004-07-01

    Recent years have witnessed a growing interest in learning how colour vision has evolved. This trend has been fuelled by an enhanced understanding of the nature and extent of colour vision among contemporary species, by a deeper understanding of the paleontological record and by the application of new tools from molecular biology. This review provides an assessment of the progress in understanding the evolution of vertebrate colour vision. In so doing, we offer accounts of the evolution of three classes of mechanism important for colour vision--photopigment opsins, oil droplets and retinal organisation--and then examine details of how colour vision has evolved among mammals and, more specifically, among primates.

  14. Tests of commercial colour CMOS cameras for astronomical applications

    NASA Astrophysics Data System (ADS)

    Pokhvala, S. M.; Reshetnyk, V. M.; Zhilyaev, B. E.

    2013-12-01

    We present some results of testing commercial colour CMOS cameras for astronomical applications. Colour CMOS sensors allow to perform photometry in three filters simultaneously that gives a great advantage compared with monochrome CCD detectors. The Bayer BGR colour system realized in colour CMOS sensors is close to the astronomical Johnson BVR system. The basic camera characteristics: read noise (e^{-}/pix), thermal noise (e^{-}/pix/sec) and electronic gain (e^{-}/ADU) for the commercial digital camera Canon 5D MarkIII are presented. We give the same characteristics for the scientific high performance cooled CCD camera system ALTA E47. Comparing results for tests of Canon 5D MarkIII and CCD ALTA E47 show that present-day commercial colour CMOS cameras can seriously compete with the scientific CCD cameras in deep astronomical imaging.

  15. Mammographic quantitative image analysis and biologic image composition for breast lesion characterization and classification

    SciTech Connect

    Drukker, Karen Giger, Maryellen L.; Li, Hui; Duewer, Fred; Malkov, Serghei; Joe, Bonnie; Kerlikowske, Karla; Shepherd, John A.; Flowers, Chris I.; Drukteinis, Jennifer S.

    2014-03-15

    Purpose: To investigate whether biologic image composition of mammographic lesions can improve upon existing mammographic quantitative image analysis (QIA) in estimating the probability of malignancy. Methods: The study population consisted of 45 breast lesions imaged with dual-energy mammography prior to breast biopsy with final diagnosis resulting in 10 invasive ductal carcinomas, 5 ductal carcinomain situ, 11 fibroadenomas, and 19 other benign diagnoses. Analysis was threefold: (1) The raw low-energy mammographic images were analyzed with an established in-house QIA method, “QIA alone,” (2) the three-compartment breast (3CB) composition measure—derived from the dual-energy mammography—of water, lipid, and protein thickness were assessed, “3CB alone”, and (3) information from QIA and 3CB was combined, “QIA + 3CB.” Analysis was initiated from radiologist-indicated lesion centers and was otherwise fully automated. Steps of the QIA and 3CB methods were lesion segmentation, characterization, and subsequent classification for malignancy in leave-one-case-out cross-validation. Performance assessment included box plots, Bland–Altman plots, and Receiver Operating Characteristic (ROC) analysis. Results: The area under the ROC curve (AUC) for distinguishing between benign and malignant lesions (invasive and DCIS) was 0.81 (standard error 0.07) for the “QIA alone” method, 0.72 (0.07) for “3CB alone” method, and 0.86 (0.04) for “QIA+3CB” combined. The difference in AUC was 0.043 between “QIA + 3CB” and “QIA alone” but failed to reach statistical significance (95% confidence interval [–0.17 to + 0.26]). Conclusions: In this pilot study analyzing the new 3CB imaging modality, knowledge of the composition of breast lesions and their periphery appeared additive in combination with existing mammographic QIA methods for the distinction between different benign and malignant lesion types.

  16. Nocturnal colour vision in geckos.

    PubMed Central

    Roth, Lina S V; Kelber, Almut

    2004-01-01

    Nocturnal animals are said to sacrifice colour vision in favour of increased absolute sensitivity. This is true for most vertebrates that possess a dual retina with a single type of rod for colour-blind night vision and multiple types of cone for diurnal colour vision. However, among the nocturnal vertebrates, geckos are unusual because they have no rods but three cone types. Here, we show that geckos use their cones for colour vision in dim light. Two specimens of the nocturnal helmet gecko Tarentola (formerly Geckonia) chazaliae were able to discriminate blue from grey patterns by colour alone. Experiments were performed at 0.002 cd m(-2), a light intensity similar to dim moonlight. We conclude that nocturnal geckos can use cone-based colour vision at very dim light levels when humans rely on colour-blind rod vision. PMID:15801611

  17. Hyperbolic geometry for colour metrics.

    PubMed

    Farup, Ivar

    2014-05-19

    It is well established from both colour difference and colour order perpectives that the colour space cannot be Euclidean. In spite of this, most colour spaces still in use today are Euclidean, and the best Euclidean colour metrics are performing comparably to state-of-the-art non-Euclidean metrics. In this paper, it is shown that a transformation from Euclidean to hyperbolic geometry (i.e., constant negative curvature) for the chromatic plane can significantly improve the performance of Euclidean colour metrics to the point where they are statistically significantly better than state-of-the-art non-Euclidean metrics on standard data sets. The resulting hyperbolic geometry nicely models both qualitatively and quantitatively the hue super-importance phenomenon observed in colour order systems.

  18. Correlative light and electron microscopy using cathodoluminescence from nanoparticles with distinguishable colours

    PubMed Central

    Glenn, D. R.; Zhang, H.; Kasthuri, N.; Schalek, R.; Lo, P. K.; Trifonov, A. S.; Park, H.; Lichtman, J. W.; Walsworth, R. L.

    2012-01-01

    Correlative light and electron microscopy promises to combine molecular specificity with nanoscale imaging resolution. However, there are substantial technical challenges including reliable co-registration of optical and electron images, and rapid optical signal degradation under electron beam irradiation. Here, we introduce a new approach to solve these problems: imaging of stable optical cathodoluminescence emitted in a scanning electron microscope by nanoparticles with controllable surface chemistry. We demonstrate well-correlated cathodoluminescence and secondary electron images using three species of semiconductor nanoparticles that contain defects providing stable, spectrally-distinguishable cathodoluminescence. We also demonstrate reliable surface functionalization of the particles. The results pave the way for the use of such nanoparticles for targeted labeling of surfaces to provide nanoscale mapping of molecular composition, indicated by cathodoluminescence colour, simultaneously acquired with structural electron images in a single instrument. PMID:23155483

  19. The development of artists' novel colour palettes for inkjet printing

    NASA Astrophysics Data System (ADS)

    Parraman, Carinna

    2010-01-01

    In this changing environment in which the artist and designer has access to a wide range of digital imaging tools and technologies, that on first glance, are dedicated to the creation of colour mixtures, why is the digital interface and colour outcome often disappointing? It appears that hardware, software tools and methods for digital printing are not necessarily suited to the specific requirements of the artist. In fact, they are too generalised to obtain a high degree of quality and too inflexible to allow artists to obtain precision and predictability. Is it possible for an artist to mix and print a colour that captures their creative imagination? The motivation for this research is based on how artists mix and print colour by traditional means (painting and printmaking) and how these differ from colour picker tools, slider bars and methods developed for digital printing, and whether it is possible to incorporate both? The paper provides a brief historical background to artists who have developed colour systems to assist their particular colour choices. Based on existing hardware and software, the paper suggests alternative approaches to colour selection, demonstrates methods for the creation of novel inkjet printed palettes, and how these can be visualised and compared.

  20. Compositional maps of Saturn's moon Phoebe from imaging spectroscopy

    USGS Publications Warehouse

    Clark, R.N.; Brown, R.H.; Jaumann, R.; Cruikshank, D.P.; Nelson, R.M.; Buratti, B.J.; McCord, T.B.; Lunine, J.; Baines, K.H.; Bellucci, G.; Bibring, J.-P.; Capaccioni, F.; Cerroni, P.; Coradini, A.; Formisano, V.; Langevin, Y.; Matson, D.L.; Mennella, V.; Nicholson, P.D.; Sicardy, B.; Sotin, C.; Hoefen, T.M.; Curchin, J.M.; Hansen, G.; Hibbits, K.; Matz, K.-D.

    2005-01-01

    The origin of Phoebe, which is the outermost large satellite of Saturn, is of particular interest because its inclined, retrograde orbit suggests that it was gravitationally captured by Saturn, having accreted outside the region of the solar nebula in which Saturn formed. By contrast, Saturn's regular satellites (with prograde, low-inclination, circular orbits) probably accreted within the sub-nebula in which Saturn itself formed. Here we report imaging spectroscopy of Phoebe resulting from the Cassini-Huygens spacecraft encounter on 11 June 2004. We mapped ferrous-iron-bearing minerals, bound water, trapped CO2, probable phyllosilicates, organics, nitriles and cyanide compounds. Detection of these compounds on Phoebe makes it one of the most compositionally diverse objects yet observed in our Solar System. It is likely that Phoebe's surface contains primitive materials from the outer Solar System, indicating a surface of cometary origin.

  1. Compositional maps of Saturn's moon Phoebe from imaging spectroscopy.

    PubMed

    Clark, Roger N; Brown, Robert H; Jaumann, Ralf; Cruikshank, Dale P; Nelson, Robert M; Buratti, Bonnie J; McCord, Thomas B; Lunine, J; Baines, K H; Bellucci, G; Bibring, J-P; Capaccioni, F; Cerroni, P; Coradini, A; Formisano, V; Langevin, Y; Matson, D L; Mennella, V; Nicholson, P D; Sicardy, B; Sotin, C; Hoefen, Todd M; Curchin, John M; Hansen, Gary; Hibbits, Karl; Matz, K-D

    2005-05-01

    The origin of Phoebe, which is the outermost large satellite of Saturn, is of particular interest because its inclined, retrograde orbit suggests that it was gravitationally captured by Saturn, having accreted outside the region of the solar nebula in which Saturn formed. By contrast, Saturn's regular satellites (with prograde, low-inclination, circular orbits) probably accreted within the sub-nebula in which Saturn itself formed. Here we report imaging spectroscopy of Phoebe resulting from the Cassini-Huygens spacecraft encounter on 11 June 2004. We mapped ferrous-iron-bearing minerals, bound water, trapped CO2, probable phyllosilicates, organics, nitriles and cyanide compounds. Detection of these compounds on Phoebe makes it one of the most compositionally diverse objects yet observed in our Solar System. It is likely that Phoebe's surface contains primitive materials from the outer Solar System, indicating a surface of cometary origin. PMID:15875014

  2. Radiopacity evaluation of contemporary resin composites by digitization of images

    PubMed Central

    Ermis, R. Banu; Yildirim, Derya; Yildiz, Gul; Gormez, Ozlem

    2014-01-01

    Objective: The aim of this study was to evaluate the radiopacity of different composite resins and compare the values to those of human enamel and dentine. Materials and Methods: Five specimens of each material with thicknesses of 2 mm were prepared and radiographed alongside aluminum step wedge and human enamel and dentin. Three occlusal radiographs for each material were taken and digitized using a desktop scanner. Mean gray values of the test materials were measured using Image J software. Then a conversion was performed according to establish the radiopacity of the test materials, in millimeters of equivalent Al. Data were analyzed using one-way analysis of variance and Duncan multiple range tests (P < 0.05). Results: The radiopacity values varied among the restorative materials (P < 0.05). The radiopacity values of the materials tested were, in decreasing order: Enamel Plus HRI > Z250 > Filtek Ultimate ≥ Z550 > Nexcomp ≥ Nanoceram Bright > enamel ≥ Estelite Sigma Quick > Clearfil Majesty Esthetic ≥ Reflexions XLS ≥ Aelite LS Posterior ≥ dentin ≥ 2 mm Al. Conclusion: All resin composite materials investigated in this study presented different radiopacity values. However, all materials had radiopacity values greater than dentin and had sufficient radiopacity to meet International Organization for Standardization 4049 standard. PMID:25202214

  3. Influence of Texture and Colour in Breast TMA Classification

    PubMed Central

    Fernández-Carrobles, M. Milagro; Bueno, Gloria; Déniz, Oscar; Salido, Jesús; García-Rojo, Marcial; González-López, Lucía

    2015-01-01

    Breast cancer diagnosis is still done by observation of biopsies under the microscope. The development of automated methods for breast TMA classification would reduce diagnostic time. This paper is a step towards the solution for this problem and shows a complete study of breast TMA classification based on colour models and texture descriptors. The TMA images were divided into four classes: i) benign stromal tissue with cellularity, ii) adipose tissue, iii) benign and benign anomalous structures, and iv) ductal and lobular carcinomas. A relevant set of features was obtained on eight different colour models from first and second order Haralick statistical descriptors obtained from the intensity image, Fourier, Wavelets, Multiresolution Gabor, M-LBP and textons descriptors. Furthermore, four types of classification experiments were performed using six different classifiers: (1) classification per colour model individually, (2) classification by combination of colour models, (3) classification by combination of colour models and descriptors, and (4) classification by combination of colour models and descriptors with a previous feature set reduction. The best result shows an average of 99.05% accuracy and 98.34% positive predictive value. These results have been obtained by means of a bagging tree classifier with combination of six colour models and the use of 1719 non-correlated (correlation threshold of 97%) textural features based on Statistical, M-LBP, Gabor and Spatial textons descriptors. PMID:26513238

  4. Digital Compositing Techniques for Coronal Imaging (Invited review)

    NASA Astrophysics Data System (ADS)

    Espenak, F.

    2000-04-01

    The solar corona exhibits a huge range in brightness which cannot be captured in any single photographic exposure. Short exposures show the bright inner corona and prominences, while long exposures reveal faint details in equatorial streamers and polar brushes. For many years, radial gradient filters and other analog techniques have been used to compress the corona's dynamic range in order to study its morphology. Such techniques demand perfect pointing and tracking during the eclipse, and can be difficult to calibrate. In the past decade, the speed, memory and hard disk capacity of personal computers have rapidly increased as prices continue to drop. It is now possible to perform sophisticated image processing of eclipse photographs on commercially available CPU's. Software programs such as Adobe Photoshop permit combining multiple eclipse photographs into a composite image which compresses the corona's dynamic range and can reveal subtle features and structures. Algorithms and digital techniques used for processing 1998 eclipse photographs will be discussed which are equally applicable to the recent eclipse of 1999 August 11.

  5. A multi-threaded mosaicking algorithm for fast image composition of fluorescence bladder images

    NASA Astrophysics Data System (ADS)

    Behrens, Alexander; Bommes, Michael; Stehle, Thomas; Gross, Sebastian; Leonhardt, Steffen; Aach, Til

    2010-02-01

    The treatment of urinary bladder cancer is usually carried out using fluorescence endoscopy. A narrow-band bluish illumination activates a tumor marker resulting in a red fluorescence. Because of low illumination power the distance between endoscope and bladder wall is kept low during the whole bladder scan, which is carried out before treatment. Thus, only a small field of view (FOV) of the operation field is provided, which impedes navigation and relocating of multi-focal tumors. Although off-line calculated panorama images can assist surgery planning, the immediate display of successively growing overview images composed from single video frames in real-time during the bladder scan, is well suited to ease navigation and reduce the risk of missing tumors. Therefore we developed an image mosaicking algorithm for fluorescence endoscopy. Due to fast computation requirements a flexible multi-threaded software architecture based on our RealTimeFrame platform is developed. Different algorithm tasks, like image feature extraction, matching and stitching are separated and applied by independent processing threads. Thus, different implementation of single tasks can be easily evaluated. In an optimization step we evaluate the trade-off between feature repeatability and total processing time, consider the thread synchronization, and achieve a constant workload of each thread. Thus, a fast computation of panoramic images is performed on a standard hardware platform, preserving full input image resolution (780x576) at the same time. Displayed on a second clinical monitor, the extended FOV of the image composition promises high potential for surgery assistance.

  6. Colour Polymorphism Protects Prey Individuals and Populations Against Predation

    PubMed Central

    Karpestam, Einat; Merilaita, Sami; Forsman, Anders

    2016-01-01

    Colour pattern polymorphism in animals can influence and be influenced by interactions between predators and prey. However, few studies have examined whether polymorphism is adaptive, and there is no evidence that the co-occurrence of two or more natural prey colour variants can increase survival of populations. Here we show that visual predators that exploit polymorphic prey suffer from reduced performance, and further provide rare evidence in support of the hypothesis that prey colour polymorphism may afford protection against predators for both individuals and populations. This protective effect provides a probable explanation for the longstanding, evolutionary puzzle of the existence of colour polymorphisms. We also propose that this protective effect can provide an adaptive explanation for search image formation in predators rather than search image formation explaining polymorphism. PMID:26902799

  7. NICE: A Computational Solution to Close the Gap from Colour Perception to Colour Categorization.

    PubMed

    Parraga, C Alejandro; Akbarinia, Arash

    2016-01-01

    The segmentation of visible electromagnetic radiation into chromatic categories by the human visual system has been extensively studied from a perceptual point of view, resulting in several colour appearance models. However, there is currently a void when it comes to relate these results to the physiological mechanisms that are known to shape the pre-cortical and cortical visual pathway. This work intends to begin to fill this void by proposing a new physiologically plausible model of colour categorization based on Neural Isoresponsive Colour Ellipsoids (NICE) in the cone-contrast space defined by the main directions of the visual signals entering the visual cortex. The model was adjusted to fit psychophysical measures that concentrate on the categorical boundaries and are consistent with the ellipsoidal isoresponse surfaces of visual cortical neurons. By revealing the shape of such categorical colour regions, our measures allow for a more precise and parsimonious description, connecting well-known early visual processing mechanisms to the less understood phenomenon of colour categorization. To test the feasibility of our method we applied it to exemplary images and a popular ground-truth chart obtaining labelling results that are better than those of current state-of-the-art algorithms.

  8. NICE: A Computational Solution to Close the Gap from Colour Perception to Colour Categorization

    PubMed Central

    Parraga, C. Alejandro; Akbarinia, Arash

    2016-01-01

    The segmentation of visible electromagnetic radiation into chromatic categories by the human visual system has been extensively studied from a perceptual point of view, resulting in several colour appearance models. However, there is currently a void when it comes to relate these results to the physiological mechanisms that are known to shape the pre-cortical and cortical visual pathway. This work intends to begin to fill this void by proposing a new physiologically plausible model of colour categorization based on Neural Isoresponsive Colour Ellipsoids (NICE) in the cone-contrast space defined by the main directions of the visual signals entering the visual cortex. The model was adjusted to fit psychophysical measures that concentrate on the categorical boundaries and are consistent with the ellipsoidal isoresponse surfaces of visual cortical neurons. By revealing the shape of such categorical colour regions, our measures allow for a more precise and parsimonious description, connecting well-known early visual processing mechanisms to the less understood phenomenon of colour categorization. To test the feasibility of our method we applied it to exemplary images and a popular ground-truth chart obtaining labelling results that are better than those of current state-of-the-art algorithms. PMID:26954691

  9. A laboratory procedure for measuring and georeferencing soil colour

    NASA Astrophysics Data System (ADS)

    Marques-Mateu, A.; Balaguer-Puig, M.; Moreno-Ramon, H.; Ibanez-Asensio, S.

    2015-04-01

    Remote sensing and geospatial applications very often require ground truth data to assess outcomes from spatial analyses or environmental models. Those data sets, however, may be difficult to collect in proper format or may even be unavailable. In the particular case of soil colour the collection of reliable ground data can be cumbersome due to measuring methods, colour communication issues, and other practical factors which lead to a lack of standard procedure for soil colour measurement and georeferencing. In this paper we present a laboratory procedure that provides colour coordinates of georeferenced soil samples which become useful in later processing stages of soil mapping and classification from digital images. The procedure requires a laboratory setup consisting of a light booth and a trichromatic colorimeter, together with a computer program that performs colour measurement, storage, and colour space transformation tasks. Measurement tasks are automated by means of specific data logging routines which allow storing recorded colour data in a spatial format. A key feature of the system is the ability of transforming between physically-based colour spaces and the Munsell system which is still the standard in soil science. The working scheme pursues the automation of routine tasks whenever possible and the avoidance of input mistakes by means of a convenient layout of the user interface. The program can readily manage colour and coordinate data sets which eventually allow creating spatial data sets. All the tasks regarding data joining between colorimeter measurements and samples locations are executed by the software in the background, allowing users to concentrate on samples processing. As a result, we obtained a robust and fully functional computer-based procedure which has proven a very useful tool for sample classification or cataloging purposes as well as for integrating soil colour data with other remote sensed and spatial data sets.

  10. Novel coloured flowers.

    PubMed

    Mol, J; Cornish, E; Mason, J; Koes, R

    1999-04-01

    The floricultural industry has focused its attention primarily on the development of novel coloured and longer living cut flowers. The basis for this was laid down some years ago through the isolation of 'blue' genes and ethylene biosynthesis genes. Recently, a novel 'blue' gene has been discovered and yellow pigments were produced in petunias by addition of a new branch to the phenylpropanoid pathway. More insight was obtained into the sequestration of anthocyanin pigments into storage vacuoles. Significant progress has been achieved in the commercialisation of genetically modified flower varieties.

  11. On the Composition of Young, Directly Imaged Giant Planets

    NASA Astrophysics Data System (ADS)

    Moses, J. I.; Marley, M. S.; Zahnle, K.; Line, M. R.; Fortney, J. J.; Barman, T. S.; Visscher, C.; Lewis, N. K.; Wolff, M. J.

    2016-10-01

    The past decade has seen significant progress on the direct detection and characterization of young, self-luminous giant planets at wide orbital separations from their host stars. Some of these planets show evidence for disequilibrium processes like transport-induced quenching in their atmospheres; photochemistry may also be important, despite the large orbital distances. These disequilibrium chemical processes can alter the expected composition, spectral behavior, thermal structure, and cooling history of the planets, and can potentially confuse determinations of bulk elemental ratios, which provide important insights into planet-formation mechanisms. Using a thermo/photochemical kinetics and transport model, we investigate the extent to which disequilibrium chemistry affects the composition and spectra of directly imaged giant exoplanets. Results for specific “young Jupiters” such as HR 8799 b and 51 Eri b are presented, as are general trends as a function of planetary effective temperature, surface gravity, incident ultraviolet flux, and strength of deep atmospheric convection. We find that quenching is very important on young Jupiters, leading to CO/CH4 and N2/NH3 ratios much greater than, and H2O mixing ratios a factor of a few less than, chemical-equilibrium predictions. Photochemistry can also be important on such planets, with CO2 and HCN being key photochemical products. Carbon dioxide becomes a major constituent when stratospheric temperatures are low and recycling of water via the {{{H}}}2 + OH reaction becomes kinetically stifled. Young Jupiters with effective temperatures ≲ 700 K are in a particularly interesting photochemical regime that differs from both transiting hot Jupiters and our own solar-system giant planets.

  12. Non-contact ultrasonic defect imaging in composites

    NASA Astrophysics Data System (ADS)

    Tenoudji, F. Cohen; Citerne, J. M.; Dutilleul, H.; Busquet, D.

    2016-02-01

    In the situations where conventional NDT ultrasonic techniques using immersion of the part under inspection or its contact with the transducers cannot be used, in-air investigation presents an alternative. The huge impedance mismatch between the part material and air (transmission loss in the order of 80 dB for a thin metallic plate) induces having to deal very small signals and unfavorable signal to noise ratios. The approach adopted here is the use of the crack of a spark generated by an induction coil as a sound source and an electrostatic polyethylene membrane microphone as a receiver [1]. The advantage of this source is that the spark power is high (several kilowatts) and its power is directly coupled to air during the energy release. In some difficult situations, an elliptical mirror is used to concentrate the sound beam power on the surface of the part [2,3]. Stability and reproducibility of the sound generated by the spark, which are a necessity in order to perform quantitative evaluations, are achieved in our experiment. This permits also an increase of the signal to noise ratio by signal accumulation. The sound pulse duration of few microseconds allows operating in pulse echo in some circumstances. The bandwidth of the source is large, of several hundred of kilohertz, and that of the microphone above 100 kHz allow the flexibility to address different kinds of materials. The technique allows an easy, in-air, non contact, inspection of structural composite parts, with pulse waves, with an excellent signal to noise ratio. An X-Y ultrasonic scanning ultrasonic system for material inspection using this technique has been realized. Results obtained in transmission and reflection are presented. Defects in carbon composite plates and in honeycomb are imaged in transmission Echographic measurements show that defect detection can be performed in thin plates using Lamb waves propagation when only one sided inspection of the part is possible.

  13. Nondestructive Evaluation of Carbon Fiber Reinforced Polymer Composites Using Reflective Terahertz Imaging.

    PubMed

    Zhang, Jin; Li, Wei; Cui, Hong-Liang; Shi, Changcheng; Han, Xiaohui; Ma, Yuting; Chen, Jiandong; Chang, Tianying; Wei, Dongshan; Zhang, Yumin; Zhou, Yufeng

    2016-06-14

    Terahertz (THz) time-domain spectroscopy (TDS) imaging is considered a nondestructive evaluation method for composite materials used for examining various defects of carbon fiber reinforced polymer (CFRP) composites and fire-retardant coatings in the reflective imaging modality. We demonstrate that hidden defects simulated by Teflon artificial inserts are imaged clearly in the perpendicular polarization mode. The THz TDS technique is also used to measure the thickness of thin fire-retardant coatings on CFRP composites with a typical accuracy of about 10 micrometers. In addition, coating debonding is successfully imaged based on the time-delay difference of the time-domain waveforms between closely adhered and debonded sample locations.

  14. Chemical composition, vitamin E content, lipid oxidation, colour and cooking losses in meat from Tudanca bulls finished on semi-extensive or intensive systems and slaughtered at 12 or 14 months.

    PubMed

    Humada, M J; Sañudo, C; Serrano, E

    2014-02-01

    The effects of production system (SE: pasture based vs. IN: concentrate based) and slaughter age (12 vs. 14 months) on chemical composition, vitamin E and myoglobin contents, lipid oxidation at 0, 3 and 6 days of display, colour and cooking losses at 2 and 7 days postmortem from thirty-three Tudanca calves were studied. SE animals showed lower IMF and greater vitamin E contents (1.2 vs. 2.9% and 4.1 vs. 1.8 μg/g, respectively). Thiobarbituric acid reactive substances (TBARS) increased (p ≤ 0.001) with display time and was greater in the IN system. After 6 days display, IN animals presented twofold TBARS values (1.4 vs. 0.8 mg malonaldehyde/kg meat). At 7 days postmortem, SE groups presented greater (p ≤ 0.05) L* and lower (p ≤ 0.05) b* and H° than IN groups. Myoglobin increased with age (3.4 to 3.9 mg/g meat), but differences (p ≤ 0.05) on a* and C* values were observed only between 12 and 14 months at 2 days postmortem.

  15. Advanced Compositional Analysis of Nanoparticle-polymer Composites Using Direct Fluorescence Imaging.

    PubMed

    Crick, Colin R; Noimark, Sacha; Peveler, William J; Bear, Joseph C; Ivanov, Aleksandar P; Edel, Joshua B; Parkin, Ivan P

    2016-01-01

    The fabrication of polymer-nanoparticle composites is extremely important in the development of many functional materials. Identifying the precise composition of these materials is essential, especially in the design of surface catalysts, where the surface concentration of the active component determines the activity of the material. Antimicrobial materials which utilize nanoparticles are a particular focus of this technology. Recently swell encapsulation has emerged as a technique for inserting antimicrobial nanoparticles into a host polymer matrix. Swell encapsulation provides the advantage of localizing the incorporation to the external surfaces of materials, which act as the active sites of these materials. However, quantification of this nanoparticle uptake is challenging. Previous studies explore the link between antimicrobial activity and surface concentration of the active component, but this is not directly visualized. Here we show a reliable method to monitor the incorporation of nanoparticles into a polymer host matrix via swell encapsulation. We show that the surface concentration of CdSe/ZnS nanoparticles can be accurately visualized through cross-sectional fluorescence imaging. Using this method, we can quantify the uptake of nanoparticles via swell encapsulation and measure the surface concentration of encapsulated particles, which is key in optimizing the activity of functional materials. PMID:27500449

  16. A universal ultraviolet-optical colour-colour-magnitude relation of galaxies

    NASA Astrophysics Data System (ADS)

    Chilingarian, Igor V.; Zolotukhin, Ivan Yu.

    2012-01-01

    The bimodal galaxy distribution in the optical colour-magnitude diagram (CMD) comprises a narrow 'red sequence' populated mostly by early-type galaxies and a broad 'blue cloud' dominated by star-forming systems. Although the optical CMD allows one to select red sequence objects, neither can it be used for galaxy classification without additional observational data such as spectra or high-resolution images, nor to identify blue galaxies at unknown redshifts. We show that adding the near ultraviolet (NUV) colour [Galaxy Evolution Explorer (GALEX) NUV λeff= 227 nm] to the optical (g - r versus Mr) CMD reveals a tight relation in the 3D colour-colour-magnitude space smoothly continuing from the 'blue cloud' to the 'red sequence'. We found that 98 per cent of 225 000 low-redshift (Z < 0.27) galaxies follow a smooth surface ? with a standard deviation of 0.03-0.07 mag making it the tightest known galaxy photometric relation, given the ˜0.9 mag range of k-corrected g - r colours. Similar relations exist in other NUV-optical colours. There is a strong correlation between morphological types and integrated ? colours of galaxies, while the connection with g - r is ambiguous. Rare galaxy classes such as E+A or tidally stripped systems become outliers that occupy distinct regions in the 3D parameter space. Using stellar population models for galaxies with different star formation histories, we show that (a) the (?) distribution at a given luminosity is formed by objects having constant and exponentially declining star formation rates with different characteristic time-scales with the red sequence part consistent also with simple stellar population; (b) colour evolution for exponentially declining models goes along the relation suggesting a weak evolution of its shape up to a redshift of 0.9; (c) galaxies with truncated star formation histories have very short transition phase offset from the relation thus explaining the rareness of E+A galaxies. This relation can be used as

  17. Linguistic determinants of word colouring in grapheme-colour synaesthesia.

    PubMed

    Simner, Julia; Glover, Louise; Mowat, Alice

    2006-02-01

    Previous studies of grapheme-colour synaesthesia have suggested that words tend to be coloured by their initial letter or initial vowel (e.g., Baron-Cohen et al., 1993; Ward et al., 2005). We examine this assumption in two ways. First, we show that letter position and syllable stress have been confounded, such that the initial letters of a word are often in stressed position (e.g., 'wo-man, 'ta-ble, 'ha-ppy). With participant JW, we separate these factors (e.g., with stress homographs such as 'con-vict vs. con-'vict) and show that the primary determinant of word colour is syllable stress, with only a secondary influence of letter position. We show that this effect derives from conceptual rather than perceptual stress, and that the effect is more prominent for synaesthetes whose words are coloured by vowels than by consonants. We examine, too, the time course of word colour generation. Slower colour naming occurs for spoken versus written stimuli, as we might expect from the additional requirement of grapheme conversion in the former. Reaction time data provide evidence, too, of incremental processing, since word colour is generated faster when the dominant grapheme is flagged early rather than late in the spoken word. Finally, we examine the role of non-dominant graphemes in word colouring and show faster colour naming when later graphemes match the dominant grapheme (e.g., ether) compared to when they do not (e.g., ethos). Taken together, our findings suggest that words are coloured incrementally by a process of competition between constituent graphemes, in which stressed graphemes and word-initial graphemes are disproportionately weighted. PMID:16683502

  18. Colourful Semantics: A Clinical Investigation

    ERIC Educational Resources Information Center

    Bolderson, Sarah; Dosanjh, Christine; Milligan, Claudine; Pring, Tim; Chiat, Shula

    2011-01-01

    Children with language difficulties often omit verbs and grammatical elements and fail to complete sentences. Bryan (1997) described "colourful semantics", a therapy she used to treat a 5-year-old boy. The therapy uses colour coding to highlight the predicate argument structure of sentences. This study further tested the therapy's effectiveness by…

  19. Complementary Colours for a Physicist

    ERIC Educational Resources Information Center

    Babic, Vitomir; Cepic, Mojca

    2009-01-01

    This paper reports on a simple experiment which enables splitting incident light into two different modes, each having a colour exactly complementary to the other. A brief historical development of colour theories and differences in a physicist's point of view with respect to an artist's one is discussed. An experimental system for producing…

  20. Reversible colour change in Arthropoda.

    PubMed

    Umbers, Kate D L; Fabricant, Scott A; Gawryszewski, Felipe M; Seago, Ainsley E; Herberstein, Marie E

    2014-11-01

    The mechanisms and functions of reversible colour change in arthropods are highly diverse despite, or perhaps due to, the presence of an exoskeleton. Physiological colour changes, which have been recorded in 90 arthropod species, are rapid and are the result of changes in the positioning of microstructures or pigments, or in the refractive index of layers in the integument. By contrast, morphological colour changes, documented in 31 species, involve the anabolism or catabolism of components (e.g. pigments) directly related to the observable colour. In this review we highlight the diversity of mechanisms by which reversible colour change occurs and the evolutionary context and diversity of arthropod taxa in which it has been observed. Further, we discuss the functions of reversible colour change so far proposed, review the limited behavioural and ecological data, and argue that the field requires phylogenetically controlled approaches to understanding the evolution of reversible colour change. Finally, we encourage biologists to explore new model systems for colour change and to engage scientists from other disciplines; continued cross-disciplinary collaboration is the most promising approach to this nexus of biology, physics, and chemistry.

  1. The colour of gender stereotyping.

    PubMed

    Cunningham, Sheila J; Macrae, C Neil

    2011-08-01

    Despite legislative attempts to eliminate gender stereotyping from society, the propensity to evaluate people on the basis of their sex remains a pernicious social problem. Noting the critical interplay between cultural and cognitive factors in the establishment of stereotypical beliefs, the current investigation explored the extent to which culturally transmitted colour-gender associations (i.e., pink is for girls, blue is for boys) set the stage for the automatic activation and expression of gender stereotypes. Across six experiments, the results demonstrated that (1) consumer choice for children's goods is dominated by gender-stereotyped colours (Experiment 1); (2) colour-based stereotypic associations guide young children's behaviour (Experiment 2); (3) colour-gender associations automatically activate associated stereotypes in adulthood (Experiments 3-5); and (4) colour-based stereotypic associations bias impressions of male and female targets (Experiment 6). These findings indicate that, despite prohibitions against stereotyping, seemingly innocuous societal practices may continue to promote this mode of thought.

  2. Profile detection by projection of coloured patterns

    NASA Astrophysics Data System (ADS)

    Fontani, Daniela; Francini, Franco; Sansoni, Paola; Jafrancesco, David; Mercatelli, Luca

    2007-06-01

    The paper presents a study to detect the three-dimensional profile of an object using a technique based on the projection of colour-coded lines. The accessibility at low-cost of projectors and digital photographic cameras has approved the employment and the development of these techniques. They provide information concerning the profile through the acquisition of a couple of images. The first one concerns a reference plane and it is captured only once, while the second one refers to the object image. The proposed methodology simplifies the individuation of homologous lines within the two images, when grating projection techniques are employed. Even though these methods are conceptually very simple, they are rarely applied because of this difficulty in stating the correspondence between observed deformation and projected line. The attribution of a different colour to every single line, or to a set of them, introduces an element useful for their selection. After the image acquisition, the data pertaining to the profile are extracted examining the image by means of an algorithm developed in Matlab language for this application. The research work is in progress beyond the results presented in this paper, which already represent a excellent starting point for further studies and evolutions of the technique.

  3. The Colour of the Young Universe

    NASA Astrophysics Data System (ADS)

    2003-12-01

    field was visible from the ESO Paranal Observatory and the atmospheric conditions were optimal, ESO astronomers pointed the 8.2-m VLT ANTU telescope in this direction, taking near-infrared images with the ISAAC multi-mode instrument. Altogether, the field was observed for more than 100 hours and the resulting images (see ESO PR 23/02 ), are the deepest ground-based views in the near-infrared Js- and H-bands. The Ks-band image is the deepest ever obtained of any sky field in this spectral band, whether from the ground or from space. These unique data provide an exceptional view and have now allowed unprecedented studies of the galaxy population in the young Universe. Indeed, because of the exceptional seeing conditions at Paranal, the data obtained with the VLT have an excellent image sharpness (a "seeing" of 0.48 arcsec) and can be combined with the HST optical data with almost no loss of quality. A bluer colour ESO PR Photo 34/03 ESO PR Photo 34/03 [Preview - JPEG: 501 x 400 pix - 21k [Normal - JPEG: 1003 x 800 pix - 178k] [Full Res - JPEG: 1200 x 958 pix - 230k] Captions : PR Photo 34a/03 shows a set of three-colour images of intrinsically bright galaxies in the Hubble Deep Field South. The galaxies are arranged horizontally by the age of the Universe when the light left each object. For reference, the Universe is now 13.7 billion years old. The colours of the galaxies have had the effect of redshift removed [2]. That is, the colours indicate the amount of light which is emitted at a given rest-frame wavelength, as observed by someone at the same redshift as each galaxy. These colours provide information about the ages of stars in the galaxies, where redder colours indicate older stars. At the bottom is shown how the mean colour of bright galaxies changes as the Universe gets older. The reddening in colour with time is due to the increasing mean age of the stars, cf. the text. The astronomers were able to detect unambiguously about 300 galaxies on these images. For

  4. Using digital colour to increase the realistic appearance of SEM micrographs of bloodstains.

    PubMed

    Hortolà, Policarp

    2010-10-01

    Although in the scientific-research literature the micrographs from scanning electron microscopes (SEMs) are usually displayed in greyscale, the potential of colour resources provided by the SEM-coupled image-acquiring systems and, subsidiarily, by image-manipulation free softwares deserves be explored as a tool for colouring SEM micrographs of bloodstains. After acquiring greyscale SEM micrographs of a (dark red to the naked eye) human blood smear on grey chert, they were manually obtained in red tone using both the SEM-coupled image-acquiring system and an image-manipulation free software, as well as they were automatically generated in thermal tone using the SEM-coupled system. Red images obtained by the SEM-coupled system demonstrated lower visual-discrimination capability than the other coloured images, whereas those in red generated by the free software rendered better magnitude of scopic information than the red images generated by the SEM-coupled system. Thermal-tone images, although were further from the real sample colour than the red ones, not only increased their realistic appearance over the greyscale images, but also yielded the best visual-discrimination capability among all the coloured SEM micrographs, and fairly enhanced the relief effect of the SEM micrographs over both the greyscale and the red images. The application of digital colour by means of the facilities provided by an SEM-coupled image-acquiring system or, when required, by an image-manipulation free software provides a user-friendly, quick and inexpensive way of obtaining coloured SEM micrographs of bloodstains, avoiding to do sophisticated, time-consuming colouring procedures. Although this work was focused on bloodstains, well probably other monochromatic or quasi-monochromatic samples are also susceptible of increasing their realistic appearance by colouring them using the simple methods utilized in this study.

  5. Colour categorization by domestic chicks.

    PubMed

    Jones, C D; Osorio, D; Baddeley, R J

    2001-10-22

    Spectral stimuli form a physical continuum, which humans divide into discrete non-overlapping regions or categories that are designated by colour names. Little is known about whether non-verbal animals form categories on stimulus continua, but work in psychology and artificial intelligence provides models for stimulus generalization and categorization. We compare predictions of such models to the way poultry chicks (Gallus gallus) generalize to novel stimuli following appetitive training to either one or two colours. If the two training colours are (to human eyes) red and greenish-yellow or green and blue, chicks prefer intermediates, i.e. orange rather than red or yellow and turquoise rather than green or blue. The level of preference for intermediate colours implies that the chicks interpolate between the training stimuli. However, they do not extrapolate beyond the limits set by the training stimuli, at least for red and yellow training colours. Similarly, chicks trained to red and blue generalize to purple, but they do not generalize across grey after training to the complementary colours yellow and blue. These results are consistent with a modified version of a Bayesian model of generalization from multiple examples that was proposed by Shepard and show similarities to human colour categorization.

  6. Colour anomia resulting from weakened short-term colour memory. A case study.

    PubMed

    Davidoff, J B; Ostergaard, A L

    1984-06-01

    A patient exhibited marked colour anomia without object anomia, but was able to point to named colours. Five experiments were conducted to investigate his immediate colour memory. It was concluded that his colour anomia was the result of an impaired short-term memory deficit specific to colour. Temporary activation of specific entries in the colour lexicon enabled pointing and even naming to take place. A general model incorporating all forms of colour anomia is presented.

  7. Near infrared spectroscopic imaging assessment of cartilage composition: Validation with mid infrared imaging spectroscopy.

    PubMed

    Palukuru, Uday P; Hanifi, Arash; McGoverin, Cushla M; Devlin, Sean; Lelkes, Peter I; Pleshko, Nancy

    2016-07-01

    Disease or injury to articular cartilage results in loss of extracellular matrix components which can lead to the development of osteoarthritis (OA). To better understand the process of disease development, there is a need for evaluation of changes in cartilage composition without the requirement of extensive sample preparation. Near infrared (NIR) spectroscopy is a chemical investigative technique based on molecular vibrations that is increasingly used as an assessment tool for studying cartilage composition. However, the assignment of specific molecular vibrations to absorbance bands in the NIR spectrum of cartilage, which arise from overtones and combinations of primary absorbances in the mid infrared (MIR) spectral region, has been challenging. In contrast, MIR spectroscopic assessment of cartilage is well-established, with many studies validating the assignment of specific bands present in MIR spectra to specific molecular vibrations. In the current study, NIR imaging spectroscopic data were obtained for compositional analysis of tissues that served as an in vitro model of OA. MIR spectroscopic data obtained from the identical tissue regions were used as the gold-standard for collagen and proteoglycan (PG) content. MIR spectroscopy in transmittance mode typically requires a much shorter pathlength through the sample (≤10 microns thick) compared to NIR spectroscopy (millimeters). Thus, this study first addressed the linearity of small absorbance bands in the MIR region with increasing tissue thickness, suitable for obtaining a signal in both the MIR and NIR regions. It was found that the linearity of specific, small MIR absorbance bands attributable to the collagen and PG components of cartilage (at 1336 and 856 cm(-1), respectively) are maintained through a thickness of 60 μm, which was also suitable for NIR data collection. MIR and NIR spectral data were then collected from 60 μm thick samples of cartilage degraded with chondroitinase ABC as a model

  8. Near infrared spectroscopic imaging assessment of cartilage composition: Validation with mid infrared imaging spectroscopy.

    PubMed

    Palukuru, Uday P; Hanifi, Arash; McGoverin, Cushla M; Devlin, Sean; Lelkes, Peter I; Pleshko, Nancy

    2016-07-01

    Disease or injury to articular cartilage results in loss of extracellular matrix components which can lead to the development of osteoarthritis (OA). To better understand the process of disease development, there is a need for evaluation of changes in cartilage composition without the requirement of extensive sample preparation. Near infrared (NIR) spectroscopy is a chemical investigative technique based on molecular vibrations that is increasingly used as an assessment tool for studying cartilage composition. However, the assignment of specific molecular vibrations to absorbance bands in the NIR spectrum of cartilage, which arise from overtones and combinations of primary absorbances in the mid infrared (MIR) spectral region, has been challenging. In contrast, MIR spectroscopic assessment of cartilage is well-established, with many studies validating the assignment of specific bands present in MIR spectra to specific molecular vibrations. In the current study, NIR imaging spectroscopic data were obtained for compositional analysis of tissues that served as an in vitro model of OA. MIR spectroscopic data obtained from the identical tissue regions were used as the gold-standard for collagen and proteoglycan (PG) content. MIR spectroscopy in transmittance mode typically requires a much shorter pathlength through the sample (≤10 microns thick) compared to NIR spectroscopy (millimeters). Thus, this study first addressed the linearity of small absorbance bands in the MIR region with increasing tissue thickness, suitable for obtaining a signal in both the MIR and NIR regions. It was found that the linearity of specific, small MIR absorbance bands attributable to the collagen and PG components of cartilage (at 1336 and 856 cm(-1), respectively) are maintained through a thickness of 60 μm, which was also suitable for NIR data collection. MIR and NIR spectral data were then collected from 60 μm thick samples of cartilage degraded with chondroitinase ABC as a model

  9. Meaning-Making with Colour in Multimodal Texts: An 11-Year-Old Student's Purposeful "Doing"

    ERIC Educational Resources Information Center

    Pantaleo, Sylvia

    2012-01-01

    Colour, a visual element of art and design, is a semiotic mode that is used strategically by sign-makers to communicate meaning. Understanding the meaning-making potential of colour can enhance students' understanding, appreciation, interpretation and composition of multimodal texts. This article features a case study of Anya, an 11-year-old…

  10. Artist: Ken Hodges Composite image explaining Objective and Motivation for Galileo Probe Heat Loads:

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Artist: Ken Hodges Composite image explaining Objective and Motivation for Galileo Probe Heat Loads: Galileo Probe descending into Jupiters Atmosphere shows heat shield separation with parachute deployed. (Ref. JPL P-19180)

  11. Feasibility of generating quantitative composition images in dual energy mammography: a simulation study

    NASA Astrophysics Data System (ADS)

    Lee, Donghoon; Kim, Ye-seul; Choi, Sunghoon; Lee, Haenghwa; Choi, Seungyeon; Kim, Hee-Joung

    2016-03-01

    Breast cancer is one of the most common malignancies in women. For years, mammography has been used as the gold standard for localizing breast cancer, despite its limitation in determining cancer composition. Therefore, the purpose of this simulation study is to confirm the feasibility of obtaining tumor composition using dual energy digital mammography. To generate X-ray sources for dual energy mammography, 26 kVp and 39 kVp voltages were generated for low and high energy beams, respectively. Additionally, the energy subtraction and inverse mapping functions were applied to provide compositional images. The resultant images showed that the breast composition obtained by the inverse mapping function with cubic fitting achieved the highest accuracy and least noise. Furthermore, breast density analysis with cubic fitting showed less than 10% error compare to true values. In conclusion, this study demonstrated the feasibility of creating individual compositional images and capability of analyzing breast density effectively.

  12. Resurgence of natural colourants: a holistic view.

    PubMed

    Kumar, J K; Sinha, A K

    2004-02-01

    Today, natural colourants are emerging globally, leaving synthetic colourants behind in the race, due to the realisation that are safer and ecofriendly in nature. In this context, a brief review of natural colourant sources, their classification, chemical constituents responsible for producing different colours, its activities and effect of different mordants on the hue is discussed.

  13. Neuronal correlates of colour-graphemic synaesthesia: a fMRI study.

    PubMed

    Sperling, Julia M; Prvulovic, David; Linden, David E J; Singer, Wolf; Stirn, Aglaja

    2006-02-01

    Synaesthesia is a perceptual phenomenon in which specific events in one sensory modality induce experiences in another. In colour-graphemic synaesthesia, subjects report colour experiences induced by written letters. Our subjects displayed this type of synaesthesia, as verified by a test of the consistency of the perceptual associations over time, and had no history of neurological or psychiatric disorders. We investigated the hypothesis that the synaesthetic colour experience is accompanied by an activation of the human colour area (V4/V8) using functional magnetic resonance imaging (fMRI). With retinotopic and colour mapping we could confirm that colour stimuli specifically activate area V4/V8. For the study of colour-graphemic synaesthesia we used an AB boxcar design with blocks of letters that elicited a synaesthetic colour experience (condition A) alternating with blocks of letters that did not (condition B). In both hemispheres condition A led to a significantly higher activation of V4/V8 than condition B. These findings support the hypothesis that the grapheme-induced colour perception in synaesthesia is caused by an activation of the colour areas of the human visual cortex.

  14. Beyond a Dichotomic Approach, the Case of Colour Phenomena

    ERIC Educational Resources Information Center

    Viennot, L.; de Hosson, C.

    2012-01-01

    This research documents the aims and the impact of a teaching experiment concerning colour phenomena. This teaching experiment is designed in order to make students consider not only the spectral composition of light but also its intensity, and to consider the absorption of light by a pigment as relative, instead of as total or zero. Eight…

  15. Influence of dental resin material composition on cross-polarization-optical coherence tomography imaging

    PubMed Central

    Lammeier, Carmen; Li, YuPing; Lunos, Scott; Fok, Alex; Rudney, Joel

    2012-01-01

    Abstract. The purpose of this study was to investigate cross-polarization-optical coherence tomography (CP-OCT) signal attenuation through different resin material compositions. Four distinct composite systems were used: Filtek supreme ultra (FSU) (3M ESPE), IPS empress direct (EMD) (Ivoclar Vivadent), estelite sigma quick (SQK) (Tokuyama Dental), and Z100 (3M ESPE). Cross-sectional images of different composite-demineralized phantoms (n=108) were collected using a 1310-nm intraoral cross-polarization swept source OCT (CP-OCT) imaging system. %T quantified the CP-OCT signal attenuation. Scanning electron microscopy, transmission electron microscopy, and energy-dispersive x-ray spectrometer chemical analysis was utilized to determine how different matrix/filler compositions affected attenuation of the near infrared (NIR) signal. CP-OCT imaging of dental resin composites showed enormous variation in signal attenuation. For each of our composite systems, there was not a consistent attenuation difference in the NIR signal for A to D shades. The four composites had similar measured backscattering values but attenuated the overall signal to different degrees. When comparing the A2 shades between the four different composite systems, the order of highest to lowest of %T was EMD>Z100, FSU>SQK (ANOVA, Tukey, p<0.0001). As a result, we demonstrate the importance of understanding how the constituents of composite materials affect CP-OCT signal attenuation. PMID:23224001

  16. Influence of dental resin material composition on cross-polarization-optical coherence tomography imaging.

    PubMed

    Lammeier, Carmen; Li, YuPing; Lunos, Scott; Fok, Alex; Rudney, Joel; Jones, Robert S

    2012-10-01

    The purpose of this study was to investigate cross-polarization-optical coherence tomography (CP-OCT) signal attenuation through different resin material compositions. Four distinct composite systems were used: Filtek supreme ultra (FSU) (3M ESPE), IPS empress direct (EMD) (Ivoclar Vivadent), estelite sigma quick (SQK) (Tokuyama Dental), and Z100 (3M ESPE). Cross-sectional images of different composite-demineralized phantoms (n=108) were collected using a 1310-nm intraoral cross-polarization swept source OCT (CP-OCT) imaging system. %T quantified the CP-OCT signal attenuation. Scanning electron microscopy, transmission electron microscopy, and energy-dispersive x-ray spectrometer chemical analysis was utilized to determine how different matrix/filler compositions affected attenuation of the near infrared (NIR) signal. CP-OCT imaging of dental resin composites showed enormous variation in signal attenuation. For each of our composite systems, there was not a consistent attenuation difference in the NIR signal for A to D shades. The four composites had similar measured backscattering values but attenuated the overall signal to different degrees. When comparing the A2 shades between the four different composite systems, the order of highest to lowest of %T was EMD>Z100, FSU>SQK (ANOVA, Tukey, p<0.0001). As a result, we demonstrate the importance of understanding how the constituents of composite materials affect CP-OCT signal attenuation.

  17. Influence of dental resin material composition on cross-polarization-optical coherence tomography imaging

    NASA Astrophysics Data System (ADS)

    Lammeier, Carmen; Li, YuPing; Lunos, Scott; Fok, Alex; Rudney, Joel; Jones, Robert S.

    2012-10-01

    The purpose of this study was to investigate cross-polarization-optical coherence tomography (CP-OCT) signal attenuation through different resin material compositions. Four distinct composite systems were used: Filtek supreme ultra (FSU) (3M ESPE), IPS empress direct (EMD) (Ivoclar Vivadent), estelite sigma quick (SQK) (Tokuyama Dental), and Z100 (3M ESPE). Cross-sectional images of different composite-demineralized phantoms (n=108) were collected using a 1310-nm intraoral cross-polarization swept source OCT (CP-OCT) imaging system. %T quantified the CP-OCT signal attenuation. Scanning electron microscopy, transmission electron microscopy, and energy-dispersive x-ray spectrometer chemical analysis was utilized to determine how different matrix/filler compositions affected attenuation of the near infrared (NIR) signal. CP-OCT imaging of dental resin composites showed enormous variation in signal attenuation. For each of our composite systems, there was not a consistent attenuation difference in the NIR signal for A to D shades. The four composites had similar measured backscattering values but attenuated the overall signal to different degrees. When comparing the A2 shades between the four different composite systems, the order of highest to lowest of %T was EMD>Z100, FSU>SQK (ANOVA, Tukey, p<0.0001). As a result, we demonstrate the importance of understanding how the constituents of composite materials affect CP-OCT signal attenuation.

  18. Investigation of MINACE composite filter capabilities for multicolor images correlation recognition purposes

    NASA Astrophysics Data System (ADS)

    Evtikhiev, N. N.; Zlokazov, E. Yu; Petrova, E. K.; Starikov, R. S.; Shaulskiy, D. V.

    2016-08-01

    Article represents the results of investigations in the area of distortion invariant images recognition using composite correlation filters. One of the most successive for application is a filter known as MINACE (minimum noise and average correlation energy). The capabilities of MINACE filter synthesis for multicolor image recognition problem are discussed.

  19. Environmental factors which may have led to the appearance of colour vision.

    PubMed

    Maximov, V V

    2000-09-29

    It is hypothesized that colour vision and opponent processing of colour signals in the visual system evolved as a means of overcoming the extremely unfavourable lighting conditions in the natural environment of early vertebrates. The significant flicker of illumination inherent in the shallow-water environment complicated the visual process in the achromatic case, in particular preventing early detection of enemies. The presence of two spectral classes of photoreceptors and opponent interaction of their signals at a subsequent retinal level allowed elimination of the flicker from the retinal image. This new visual function provided certain advantages concerning reaction times and favoured survival. This assumption explains why the building blocks for colour vision arose so early, i.e. just after the active predatory lifestyle was mastered. The principal functions of colour vision inherent in extant animals required a more complex neural machinery for colour processing and evolved later as the result of a change in visual function favouring colour vision.

  20. Environmental factors which may have led to the appearance of colour vision.

    PubMed Central

    Maximov, V V

    2000-01-01

    It is hypothesized that colour vision and opponent processing of colour signals in the visual system evolved as a means of overcoming the extremely unfavourable lighting conditions in the natural environment of early vertebrates. The significant flicker of illumination inherent in the shallow-water environment complicated the visual process in the achromatic case, in particular preventing early detection of enemies. The presence of two spectral classes of photoreceptors and opponent interaction of their signals at a subsequent retinal level allowed elimination of the flicker from the retinal image. This new visual function provided certain advantages concerning reaction times and favoured survival. This assumption explains why the building blocks for colour vision arose so early, i.e. just after the active predatory lifestyle was mastered. The principal functions of colour vision inherent in extant animals required a more complex neural machinery for colour processing and evolved later as the result of a change in visual function favouring colour vision. PMID:11079406

  1. Class separation improvements in pixel classification using colour injection.

    PubMed

    Blanco, Edward; Mazo, Manuel; Bergasa, Luis; Palazuelos, Sira; Rodríguez, Jose; Losada, Cristina; Martín, Jose

    2010-01-01

    This paper presents an improvement in the colour image segmentation in the Hue Saturation (HS) sub-space. The authors propose to inject (add) a colour vector in the Red Green Blue (RGB) space to increase the class separation in the HS plane. The goal of the work is the development of an algorithm to obtain the optimal colour vector for injection that maximizes the separation between the classes in the HS plane. The chromatic Chrominace-1 Chrominance-2 sub-space (of the Luminance Chrominace-1 Chrominance-2 (YC(1)C(2)) space) is used to obtain the optimal vector to add. The proposal is applied on each frame of a colour image sequence in real-time. It has been tested in applications with reduced contrast between the colours of the background and the object, and particularly when the size of the object is very small in comparison with the size of the captured scene. Numerous tests have confirmed that this proposal improves the segmentation process, considerably reducing the effects of the variation of the light intensity of the scene. Several tests have been made in skin segmentation in applications for sign language recognition via computer vision, where an accurate segmentation of hands and face is required.

  2. Class Separation Improvements in Pixel Classification Using Colour Injection

    PubMed Central

    Blanco, Edward; Mazo, Manuel; Bergasa, Luis; Palazuelos, Sira; Rodríguez, Jose; Losada, Cristina; Martín, Jose

    2010-01-01

    This paper presents an improvement in the colour image segmentation in the Hue Saturation (HS) sub-space. The authors propose to inject (add) a colour vector in the Red Green Blue (RGB) space to increase the class separation in the HS plane. The goal of the work is the development of an algorithm to obtain the optimal colour vector for injection that maximizes the separation between the classes in the HS plane. The chromatic Chrominace-1 Chrominance-2 sub-space (of the Luminance Chrominace-1 Chrominance-2 (YC1C2) space) is used to obtain the optimal vector to add. The proposal is applied on each frame of a colour image sequence in real-time. It has been tested in applications with reduced contrast between the colours of the background and the object, and particularly when the size of the object is very small in comparison with the size of the captured scene. Numerous tests have confirmed that this proposal improves the segmentation process, considerably reducing the effects of the variation of the light intensity of the scene. Several tests have been made in skin segmentation in applications for sign language recognition via computer vision, where an accurate segmentation of hands and face is required. PMID:22163628

  3. Colour-reproduction algorithm for transmitting variable video frames and its application to capsule endoscopy.

    PubMed

    Khan, Tareq; Shrestha, Ravi; Imtiaz, Md Shamin; Wahid, Khan A

    2015-04-01

    Presented is a new power-efficient colour generation algorithm for wireless capsule endoscopy (WCE) application. In WCE, transmitting colour image data from the human intestine through radio frequency (RF) consumes a huge amount of power. The conventional way is to transmit all R, G and B components of all frames. Using the proposed dictionary-based colour generation scheme, instead of sending all R, G and B frames, first one colour frame is sent followed by a series of grey-scale frames. At the receiver end, the colour information is extracted from the colour frame and then added to colourise the grey-scale frames. After a certain number of grey-scale frames, another colour frame is sent followed by the same number of grey-scale frames. This process is repeated until the end of the video sequence to maintain the colour similarity. As a result, over 50% of RF transmission power can be saved using the proposed scheme, which will eventually lead to a battery life extension of the capsule by 4-7 h. The reproduced colour images have been evaluated both statistically and subjectively by professional gastroenterologists. The algorithm is finally implemented using a WCE prototype and the performance is validated using an ex-vivo trial. PMID:26609405

  4. Colour-reproduction algorithm for transmitting variable video frames and its application to capsule endoscopy

    PubMed Central

    Khan, Tareq; Shrestha, Ravi; Imtiaz, Md. Shamin

    2015-01-01

    Presented is a new power-efficient colour generation algorithm for wireless capsule endoscopy (WCE) application. In WCE, transmitting colour image data from the human intestine through radio frequency (RF) consumes a huge amount of power. The conventional way is to transmit all R, G and B components of all frames. Using the proposed dictionary-based colour generation scheme, instead of sending all R, G and B frames, first one colour frame is sent followed by a series of grey-scale frames. At the receiver end, the colour information is extracted from the colour frame and then added to colourise the grey-scale frames. After a certain number of grey-scale frames, another colour frame is sent followed by the same number of grey-scale frames. This process is repeated until the end of the video sequence to maintain the colour similarity. As a result, over 50% of RF transmission power can be saved using the proposed scheme, which will eventually lead to a battery life extension of the capsule by 4–7 h. The reproduced colour images have been evaluated both statistically and subjectively by professional gastroenterologists. The algorithm is finally implemented using a WCE prototype and the performance is validated using an ex-vivo trial. PMID:26609405

  5. Colour effects on extracted teeth after a tooth whitening regime: assessment in an artificial oral cavity.

    PubMed

    Lath, D L; Wildgoose, D G

    2007-12-01

    The purpose of this study was to assess the reliability of a digital image analysis system and to assess its suitability for quantifying the colour (including whiteness) of extracted teeth in a purpose built artificial oral cavity after a whitening regime. Extracted teeth were treated with a scale and polish and a bleaching solution. The Image analysis system showed excellent intra operator repeatability. Significant tooth colour and whiteness changes occurred after the bleaching treatment. The digital image system has been shown to be a reliable and valid method for assessing colour and whiteness changes on extracted teeth after whitening treatments.

  6. The WIRCam Deep Survey. I. Counts, colours, and mass-functions derived from near-infrared imaging in the CFHTLS deep fields

    NASA Astrophysics Data System (ADS)

    Bielby, R.; Hudelot, P.; McCracken, H. J.; Ilbert, O.; Daddi, E.; Le Fèvre, O.; Gonzalez-Perez, V.; Kneib, J.-P.; Marmo, C.; Mellier, Y.; Salvato, M.; Sanders, D. B.; Willott, C. J.

    2012-09-01

    We present a new near-infrared imaging survey in the four CFHTLS deep fields: the WIRCam Deep Survey or "WIRDS". WIRDS comprises extremely deep, high quality (FWHM ~ 0.6″) J, H, and Ks imaging covering a total effective area of 2.1 deg2 and reaching AB 50% completeness limits of ≈ 24.5. We combine our images with the CFHTLS to create a unique eight-band ugrizJHKS photometric catalogues in the four CFHTLS deep fields; these four separate fields allow us to make a robust estimate of the effect of cosmic variance for all our measurements. We use these catalogues in combination with ≈ 9800 spectroscopic redshifts to estimate precise photometric redshifts (σΔz/(1 + z) ≲ 0.03 at i < 25), galaxy types, star-formation rates and stellar masses for a unique sample of ≈ 1.8 million galaxies. Our JHKs number counts are consistent with previous studies. We apply the "BzK" selection to our gzK filter set and find that the star forming BzK selection successfully selects 76% of star-forming galaxies in the redshift range 1.4 < z < 2.5 in our photometric catalogue, based on our photometric redshift measurement. Similarly the passive BzK selection returns 52% of the passive 1.4 < z < 2.5 population identified in the photometric catalogue. We present the mass functions of the total galaxy population as a function of redshift up to z = 2 and present fits using double Schechter functions. A mass-dependent evolution of the mass function is seen with the numbers of galaxies with masses of M ≲ 1010.75 still evolving at z ≲ 1, but galaxies of higher mass reaching their present day numbers by z ~ 0.8-1. This is consistent with the present picture of downsizing in galaxy evolution. We compare our results with the predictions of the GALFORM semi-analytical galaxy formation model and find that the simulations provide a relatively successful fit to the observed mass functions at intermediate masses (i.e. 10 ≲ log (M/M⊙) ≲ 11). However, as is common with semi

  7. Thermographic imaging for high-temperature composite materials: A defect detection study

    NASA Technical Reports Server (NTRS)

    Roth, Don J.; Bodis, James R.; Bishop, Chip

    1995-01-01

    The ability of a thermographic imaging technique for detecting flat-bottom hole defects of various diameters and depths was evaluated in four composite systems (two types of ceramic matrix composites, one metal matrix composite, and one polymer matrix composite) of interest as high-temperature structural materials. The holes ranged from 1 to 13 mm in diameter and 0.1 to 2.5 mm in depth in samples approximately 2-3 mm thick. The thermographic imaging system utilized a scanning mirror optical system and infrared (IR) focusing lens in conjunction with a mercury cadmium telluride infrared detector element to obtain high resolution infrared images. High intensity flash lamps located on the same side as the infrared camera were used to heat the samples. After heating, up to 30 images were sequentially acquired at 70-150 msec intervals. Limits of detectability based on depth and diameter of the flat-bottom holes were defined for each composite material. Ultrasonic and radiographic images of the samples were obtained and compared with the thermographic images.

  8. An electrically tunable imaging system with separable focus and zoom functions using composite liquid crystal lenses.

    PubMed

    Chen, Ming-Syuan; Chen, Po-Ju; Chen, Michael; Lin, Yi-Hsin

    2014-05-19

    We demonstrated an electrically tunable optical image system with separable focus function and zoom function based on three tunable focusing composite liquid crystal (LC) lenses. One LC lens in charge of the focus function helps to maintain the formed image at the same position and the other two LC lenses in charge of zoom function assist to continuously form an image at image sensor with tunable magnification of image size. The detail optical mechanism is investigated and the concept is demonstrated experimentally. The magnifications of the images can be switched continuously for the target in a range between 10 cm and 100 cm. The optical zoom ratio of this system maintains a constant~6.5:1 independent of the object distance. This study provides not only a guideline to design the image system with an electrically optical zoom, but also provide an experimental process to show how to operate the tunable focusing lenses in such an image system.

  9. Nondestructive Evaluation of Carbon Fiber Reinforced Polymer Composites Using Reflective Terahertz Imaging.

    PubMed

    Zhang, Jin; Li, Wei; Cui, Hong-Liang; Shi, Changcheng; Han, Xiaohui; Ma, Yuting; Chen, Jiandong; Chang, Tianying; Wei, Dongshan; Zhang, Yumin; Zhou, Yufeng

    2016-01-01

    Terahertz (THz) time-domain spectroscopy (TDS) imaging is considered a nondestructive evaluation method for composite materials used for examining various defects of carbon fiber reinforced polymer (CFRP) composites and fire-retardant coatings in the reflective imaging modality. We demonstrate that hidden defects simulated by Teflon artificial inserts are imaged clearly in the perpendicular polarization mode. The THz TDS technique is also used to measure the thickness of thin fire-retardant coatings on CFRP composites with a typical accuracy of about 10 micrometers. In addition, coating debonding is successfully imaged based on the time-delay difference of the time-domain waveforms between closely adhered and debonded sample locations. PMID:27314352

  10. Nondestructive Evaluation of Carbon Fiber Reinforced Polymer Composites Using Reflective Terahertz Imaging

    PubMed Central

    Zhang, Jin; Li, Wei; Cui, Hong-Liang; Shi, Changcheng; Han, Xiaohui; Ma, Yuting; Chen, Jiandong; Chang, Tianying; Wei, Dongshan; Zhang, Yumin; Zhou, Yufeng

    2016-01-01

    Terahertz (THz) time-domain spectroscopy (TDS) imaging is considered a nondestructive evaluation method for composite materials used for examining various defects of carbon fiber reinforced polymer (CFRP) composites and fire-retardant coatings in the reflective imaging modality. We demonstrate that hidden defects simulated by Teflon artificial inserts are imaged clearly in the perpendicular polarization mode. The THz TDS technique is also used to measure the thickness of thin fire-retardant coatings on CFRP composites with a typical accuracy of about 10 micrometers. In addition, coating debonding is successfully imaged based on the time-delay difference of the time-domain waveforms between closely adhered and debonded sample locations. PMID:27314352

  11. The effect of stress and stress hormones on dynamic colour-change in a sexually dichromatic Australian frog.

    PubMed

    Kindermann, Christina; Narayan, Edward J; Wild, Francis; Wild, Clyde H; Hero, Jean-Marc

    2013-06-01

    Rapid colour changes in vertebrates have fascinated biologists for centuries, herein we demonstrate dynamic colour change in an anuran amphibian, the stony creek frog (Litoria wilcoxii), which turns from brown to bright (lemon) yellow during amplexus. We show this by comparing the colour of baseline (unpaired males) and amplecting (paired) males. We also investigate the possible role of stress and stress hormones on this colour change. Frogs were subjected to four different levels of stressors (handling, toe-clipping, saline injection and adrenocorticotropic hormone [ACTH] injection) and the colour change was measured using digital photography. A comparison of baseline colour and stress hormone (corticosterone) levels was also conducted to give further insight to this topic. From the images, the Red Blue Green (RGB) colour values were calculated, and a principal components analysis (PCA) was used to create a single colour metric (the major axis) as an index of colour in the visible spectrum. A moderate stressor (toe-clipping) led to a significant change in colour (within 10 min) similar to that of amplecting males. Surprisingly, neither a mild stressor (handling and saline injection) nor the maximum stressor (handling and ACTH injection) led to a lightening response. This study confirms that the dynamic male colour change in this species in response to medium stressors adds new knowledge to the understanding of the functional mechanisms of dynamic colour change in amphibians.

  12. NDE of composite structures using microwave time reversal imaging

    NASA Astrophysics Data System (ADS)

    Mukherjee, Saptarshi; Tamburrino, Antonello; Udpa, Lalita; Udpa, Satish

    2016-02-01

    Composite materials are being increasingly used to replace metals, partially or completely, in aerospace, shipping and automotive industries because of their light weight, corrosion resistance, and mechanical strength. Integrity of these materials may be compromised during manufacturing or due to impact damage during usage, resulting in defects such as porosity, delamination, cracks and disbonds. Microwave NDE techniques have the ability to propagate through composite materials, without suffering much attenuation. The scattered fields depend on the dielectric properties of the medium, and hence provide information about the structural integrity of these materials. Time Reversal focusing is based on the fact that when a wave solution is reversed in time and back propagated it refocuses back at the source. This paper presents a model based parametric study of time reversal principles with microwave data in composite materials. A two dimensional FDTD model is developed to implement the forward and time reversed electromagnetic wave propagation in a test geometry comprising metal-composite structures. Simulation results demonstrate the feasibility of this approach to detect and characterize different defects.

  13. Synthetic aperture radar images with composite azimuth resolution

    DOEpatents

    Bielek, Timothy P; Bickel, Douglas L

    2015-03-31

    A synthetic aperture radar (SAR) image is produced by using all phase histories of a set of phase histories to produce a first pixel array having a first azimuth resolution, and using less than all phase histories of the set to produce a second pixel array having a second azimuth resolution that is coarser than the first azimuth resolution. The first and second pixel arrays are combined to produce a third pixel array defining a desired SAR image that shows distinct shadows of moving objects while preserving detail in stationary background clutter.

  14. The colour of an avifauna: A quantitative analysis of the colour of Australian birds

    PubMed Central

    Delhey, Kaspar

    2015-01-01

    Animal coloration is a poorly-understood aspect of phenotypic variability. Here I expand initial studies of the colour gamut of birds by providing the first quantitative description of the colour variation of an entire avifauna: Australian landbirds (555 species). The colour of Australian birds occupies a small fraction (19%) of the entire possible colour space and colour variation is extremely uneven. Most colours are unsaturated, concentrated in the centre of colour space and based on the deposition of melanins. Other mechanisms of colour production are less common but account for larger portions of colour space and for most saturated colours. Male colours occupy 45–25% more colour space than female colours, indicating that sexual dichromatism translates into a broader range of male colours. Male-exclusive colours are often saturated, at the edge of chromatic space, and have most likely evolved for signalling. While most clades of birds occupy expected or lower-than-expected colour volumes, parrots and cockatoos (Order Psittaciformes) occupy a much larger volume than expected. This uneven distribution of colour variation across mechanisms of colour production, sexes and clades is probably shared by avifaunas in other parts of the world, but this remains to be tested with comparable data. PMID:26679370

  15. The colour of an avifauna: A quantitative analysis of the colour of Australian birds.

    PubMed

    Delhey, Kaspar

    2015-01-01

    Animal coloration is a poorly-understood aspect of phenotypic variability. Here I expand initial studies of the colour gamut of birds by providing the first quantitative description of the colour variation of an entire avifauna: Australian landbirds (555 species). The colour of Australian birds occupies a small fraction (19%) of the entire possible colour space and colour variation is extremely uneven. Most colours are unsaturated, concentrated in the centre of colour space and based on the deposition of melanins. Other mechanisms of colour production are less common but account for larger portions of colour space and for most saturated colours. Male colours occupy 45-25% more colour space than female colours, indicating that sexual dichromatism translates into a broader range of male colours. Male-exclusive colours are often saturated, at the edge of chromatic space, and have most likely evolved for signalling. While most clades of birds occupy expected or lower-than-expected colour volumes, parrots and cockatoos (Order Psittaciformes) occupy a much larger volume than expected. This uneven distribution of colour variation across mechanisms of colour production, sexes and clades is probably shared by avifaunas in other parts of the world, but this remains to be tested with comparable data. PMID:26679370

  16. Multispectral near-infrared imaging of composite restorations in extracted teeth

    NASA Astrophysics Data System (ADS)

    Logan, Cooper M.; Co, Katrina U.; Fried, William A.; Simon, Jacob C.; Staninec, Michal; Fried, Daniel; Darling, Cynthia L.

    2014-02-01

    One major advantage of composite restoration materials is that they can be color matched to the tooth. However, this presents a challenge when composites fail and they need to be replaced. Dentists typically spend more time repairing and replacing composites than placing new restorations. Previous studies have shown that near-infrared imaging can be used to distinguish between sound enamel and decay due to the differences in light scattering. The purpose of this study was to use a similar approach and exploit differences in light scattering to attain high contrast between composite and tooth structure. Extracted human teeth with composites (n=16) were imaged in occlusal transmission mode at wavelengths of 1300-nm, 1460-nm and 1550-nm using an InGaAs image sensor with a tungsten halogen light source with spectral filters. All samples were also imaged in the visible range using a high definition 3D digital microscope. Our results indicate that NIR wavelengths at 1460-nm and 1550-nm, coincident with higher water absorption yield the highest contrast between dental composites and tooth structure.

  17. Confocal time lapse imaging as an efficient method for the cytocompatibility evaluation of dental composites.

    PubMed

    Attik, Ghania Nina; Gritsch, Kerstin; Colon, Pierre; Grosgogeat, Brigitte

    2014-01-01

    It is generally accepted that in vitro cell material interaction is a useful criterion in the evaluation of dental material biocompatibility. The objective of this study was to use 3D CLSM time lapse confocal imaging to assess the in vitro biocompatibility of dental composites. This method provides an accurate and sensitive indication of viable cell rate in contact with dental composite extracts. The ELS extra low shrinkage, a dental composite used for direct restoration, has been taken as example. In vitro assessment was performed on cultured primary human gingival fibroblast cells using Live/Dead staining. Images were obtained with the FV10i confocal biological inverted system and analyzed with the FV10-ASW 3.1 Software. Image analysis showed a very slight cytotoxicity in the presence of the tested composite after 5 hours of time lapse. A slight decrease of cell viability was shown in contact with the tested composite extracts compared to control cells. The findings highlighted the use of 3D CLSM time lapse imaging as a sensitive method to qualitatively and quantitatively evaluate the biocompatibility behavior of dental composites.

  18. Confocal Time Lapse Imaging as an Efficient Method for the Cytocompatibility Evaluation of Dental Composites

    PubMed Central

    Attik, Ghania Nina; Gritsch, Kerstin; Colon, Pierre; Grosgogeat, Brigitte

    2014-01-01

    It is generally accepted that in vitro cell material interaction is a useful criterion in the evaluation of dental material biocompatibility. The objective of this study was to use 3D CLSM time lapse confocal imaging to assess the in vitro biocompatibility of dental composites. This method provides an accurate and sensitive indication of viable cell rate in contact with dental composite extracts. The ELS extra low shrinkage, a dental composite used for direct restoration, has been taken as example. In vitro assessment was performed on cultured primary human gingival fibroblast cells using Live/Dead staining. Images were obtained with the FV10i confocal biological inverted system and analyzed with the FV10-ASW 3.1 Software. Image analysis showed a very slight cytotoxicity in the presence of the tested composite after 5 hours of time lapse. A slight decrease of cell viability was shown in contact with the tested composite extracts compared to control cells. The findings highlighted the use of 3D CLSM time lapse imaging as a sensitive method to qualitatively and quantitatively evaluate the biocompatibility behavior of dental composites. PMID:25406737

  19. Plus Disease in Retinopathy of Prematurity: Development of Composite Images by Quantification of Expert Opinion

    PubMed Central

    Chiang, Michael F.; Gelman, Rony; Williams, Steven L.; Lee, Joo-Yeon; Casper, Daniel S.; Martinez-Perez, M. Elena; Flynn, John T.

    2008-01-01

    Purpose To demonstrate a methodology for generating composite wide-angle images of plus disease in retinopathy of prematurity (ROP), using quantitative analysis of expert opinions. Methods Thirty-four wide-angle retinal images were independently interpreted by 22 ROP experts as “plus” or “not plus.” All images were processed by the computer-based Retinal Image multiScale Analysis (RISA) system to calculate two parameters: arterial integrated curvature (AIC) and venous diameter (VD). Using a reference standard defined by expert consensus, sensitivity and specificity curves were calculated by varying the diagnostic cutoffs for AIC and VD. From these curves, individual vessels from multiple images were identified with particular diagnostic cutoffs, and were combined into composite wide-angle images using graphics-editing software. Results The values associated with 75% underdiagnosis of true plus disease (i.e., 25% sensitivity cutoff) were AIC 0.061 and VD 4.272, the values associated with 50% underdiagnosis of true plus disease (i.e., a 50% sensitivity cutoff) were AIC 0.049 and VD 4.088, and the values associated with 25% underdiagnosis of true plus disease (i.e., 75% sensitivity cutoff) were AIC 0.042 and VD 3.795. Composite wide-angle images were generated by identifying and combining individual vessels with these characteristics. Conclusions Computer-based image analysis permits quantification of retinal vascular features, and a spectrum of abnormalities is seen in ROP. Selection of appropriate vessels from multiple images can produce composite plus disease images corresponding to expert opinions. This method may be useful for educational purposes, and for development of future disease definitions based on objective, quantitative principles. PMID:18408188

  20. Increasing land-use intensity decreases floral colour diversity of plant communities in temperate grasslands.

    PubMed

    Binkenstein, Julia; Renoult, Julien P; Schaefer, H Martin

    2013-10-01

    To preserve biodiversity and ecosystem functions in a globally changing world it is crucial to understand the effect of land use on ecosystem processes such as pollination. Floral colouration is known to be central in plant-pollinator interactions. To date, it is still unknown whether land use affects the colouration of flowering plant communities. To assess the effect of land use on the diversity and composition of flower colours in temperate grasslands, we collected data on the number of flowering plant species, blossom cover and flower reflectance spectra from 69 plant communities in two German regions, Schwäbische Alb (SA) and Hainich-Dün (HD). We analysed reflectance data of flower colours as they are perceived by honeybees and studied floral colour diversity based upon spectral loci of each flowering plant species in the Maxwell triangle. Before the first mowing, flower colour diversity decreased with increasing land-use intensity in SA, accompanied by a shift of mean flower colours of communities towards an increasing proportion of white blossom cover in both regions. By changing colour characteristics of grasslands, we suggest that increasing land-use intensity can affect the flower visitor fauna in terms of visitor behaviour and diversity. These changes may in turn influence plant reproduction in grassland plant communities. Our results indicate that land use is likely to affect communication processes between plants and flower visitors by altering flower colour traits.

  1. Real-time scanning charged-particle microscope image composition with correction of drift.

    PubMed

    Cizmar, Petr; Vladár, András E; Postek, Michael T

    2011-04-01

    In this article, a new scanning electron microscopy (SEM) image composition technique is described, which can significantly reduce drift related image corruptions. Drift distortion commonly causes blur and distortions in the SEM images. Such corruption ordinarily appears when conventional image-acquisition methods, i.e., "slow scan" and "fast scan," are applied. The damage is often very significant; it may render images unusable for metrology applications, especially where subnanometer accuracy is required. The described correction technique works with a large number of quickly taken frames, which are properly aligned and then composed into a single image. Such image contains much less noise than the individual frames, while the blur and deformation is minimized. This technique also provides useful information about changes of the sample position in time, which may be applied to investigate the drift properties of the instrument without a need of additional equipment.

  2. Texture variations suppress suprathreshold brightness and colour variations.

    PubMed

    Schofield, Andrew J; Kingdom, Frederick A A

    2014-01-01

    Discriminating material changes from illumination changes is a key function of early vision. Luminance cues are ambiguous in this regard, but can be disambiguated by co-incident changes in colour and texture. Thus, colour and texture are likely to be given greater prominence than luminance for object segmentation, and better segmentation should in turn produce stronger grouping. We sought to measure the relative strengths of combined luminance, colour and texture contrast using a suprathreshhold, psychophysical grouping task. Stimuli comprised diagonal grids of circular patches bordered by a thin black line and contained combinations of luminance decrements with either violet, red, or texture increments. There were two tasks. In the Separate task the different cues were presented separately in a two-interval design, and participants indicated which interval contained the stronger orientation structure. In the Combined task the cues were combined to produce competing orientation structure in a single image. Participants had to indicate which orientation, and therefore which cue was dominant. Thus we established the relative grouping strength of each cue pair presented separately, and compared this to their relative grouping strength when combined. In this way we observed suprathreshold interactions between cues and were able to assess cue dominance at ecologically relevant signal levels. Participants required significantly more luminance and colour compared to texture contrast in the Combined compared to Separate conditions (contrast ratios differed by about 0.1 log units), showing that suprathreshold texture dominates colour and luminance when the different cues are presented in combination. PMID:25502555

  3. Ultrasonic camera automatic image depth and stitching modifications for monitoring aerospace composites

    NASA Astrophysics Data System (ADS)

    Regez, Brad; Kirikera, Goutham; Yuen, Martin Tan Hwai; Krishnaswamy, Sridhar; Lasser, Bob

    2009-03-01

    Two modifications to an ultrasonic camera system have been performed in an effort to reduce setup time and post inspection image processing. Current production ultrasonic cameras have image gates that are adjusted manually. The process to adjust them prior to each inspection consumes large amounts of time and requires a skilled operator. The authors have overcome this by integrating the A-Scan and image together such that the image gating is automatically adjusted using the A-Scan data. The system monitors the A-scan signal which is in the center of the camera's field of view (FOV) and adjusts the image gating accordingly. This integration will allow for defect detection at any depth of the inspected area. Ultrasonic camera operation requires the inspector to scan the surface manually while observing the cameras FOV in the monitor. If the monitor image indicates a defect the operator then stores that image manually and marks an index on the surface as to where the image has been acquired. The second modification automates this effort by employing a digital encoder and image capture card. The encoder is used to track movement of the camera on the structures surface, record positions, and trigger the image capture device. The images are stored real time in the buffer memory rather than on the hard drive. The storing of images in the buffer enables for a more rapid acquisition time compared to storing the images individually to the hard drive. Once the images are stored, an algorithm tracks the movement of the camera through the encoder and accordingly displays the image to the inspector. Upon completion of the scan, an algorithm digitally stitches all the images to create a single full field image. The modifications were tested on a aerospace composite laminate with known defects and the results are discussed.

  4. Northern Gulf of Mexico estuarine coloured dissolved organic matter derived from MODIS data

    EPA Science Inventory

    Coloured dissolved organic matter (CDOM) is relevant for water quality management and may become an important measure to complement future water quality assessment programmes. An approach to derive CDOM using the Moderate Resolution Imaging Spectroradiometer (MODIS) was developed...

  5. Micromachined PIN-PMN-PT Crystal Composite Transducer for High-Frequency Intravascular Ultrasound (IVUS) Imaging

    PubMed Central

    Li, Xiang; Ma, Teng; Tian, Jian; Han, Pengdi; Zhou, Qifa; Shung, K. Kirk

    2015-01-01

    In this paper, we report the use of micromachined PbIn1/2Nb1/2O3–PbMg1/3Nb2/3O3–PbTiO3 (PIN-PMN-PT) single crystal 1–3 composite material for intravascular ultrasound (IVUS) imaging application. The effective electromechanical coupling coefficient kt(eff) of the composite was measured to be 0.75 to 0.78. Acoustic impedance was estimated to be 20 MRayl. Based on the composite, needle-type and flexible-type IVUS transducers were fabricated. The composite transducer achieved an 86% bandwidth at the center frequency of 41 MHz, which resulted in a 43 μm axial resolution. Ex vivo IVUS imaging was conducted to demonstrate the improvement of axial resolution. The composite transducer was capable of identifying the three layers of a cadaver coronary artery specimen with high resolution. The PIN-PMN-PT-based composite has superior piezoelectric properties comparable to PMN-PT-based composite and its thermal stability is higher than PMN-PT. PIN-PMN-PT crystal can be an alternative approach for fabricating high-frequency composite, instead of using PMN-PT. PMID:24960706

  6. Micromachined PIN-PMN-PT crystal composite transducer for high-frequency intravascular ultrasound (IVUS) imaging.

    PubMed

    Li, Xiang; Ma, Teng; Tian, Jian; Han, Pengdi; Zhou, Qifa; Shung, K Kirk

    2014-07-01

    In this paper, we report the use of micromachined PbIn1/2Nb1/2O3-PbMg1/3Nb2/3O3-PbTiO 3 (PIN-PMNPT) single crystal 1-3 composite material for intravascular ultrasound (IVUS) imaging application. The effective electromechanical coupling coefficient kt(eff) of the composite was measured to be 0.75 to 0.78. Acoustic impedance was estimated to be 20 MRayl. Based on the composite, needle-type and flexible-type IVUS transducers were fabricated. The composite transducer achieved an 86% bandwidth at the center frequency of 41 MHz, which resulted in a 43 μm axial resolution. Ex vivo IVUS imaging was conducted to demonstrate the improvement of axial resolution. The composite transducer was capable of identifying the three layers of a cadaver coronary artery specimen with high resolution. The PIN-PMN-PT-based composite has superior piezoelectric properties comparable to PMN-PT-based composite and its thermal stability is higher than PMN-PT. PIN-PMN-PT crystal can be an alternative approach for fabricating high-frequency composite, instead of using PMN-PT. PMID:24960706

  7. Phased Array Beamforming and Imaging in Composite Laminates Using Guided Waves

    NASA Technical Reports Server (NTRS)

    Tian, Zhenhua; Leckey, Cara A. C.; Yu, Lingyu

    2016-01-01

    This paper presents the phased array beamforming and imaging using guided waves in anisotropic composite laminates. A generic phased array beamforming formula is presented, based on the classic delay-and-sum principle. The generic formula considers direction-dependent guided wave properties induced by the anisotropic material properties of composites. Moreover, the array beamforming and imaging are performed in frequency domain where the guided wave dispersion effect has been considered. The presented phased array method is implemented with a non-contact scanning laser Doppler vibrometer (SLDV) to detect multiple defects at different locations in an anisotropic composite plate. The array is constructed of scan points in a small area rapidly scanned by the SLDV. Using the phased array method, multiple defects at different locations are successfully detected. Our study shows that the guided wave phased array method is a potential effective method for rapid inspection of large composite structures.

  8. Evaluation of impact-affected areas of glass fibre thermoplastic composites from thermographic images

    NASA Astrophysics Data System (ADS)

    Boccardi, S.; Carlomagno, G. M.; Simeoli, G.; Russo, P.; Meola, C.

    2016-07-01

    The usefulness of an infrared imaging device, in terms of both acting as a mechanism for surface thermal monitoring when a specimen is being impacted and as a non-destructive evaluation technique, has already been proved. Nevertheless, past investigation has focused on mainly thermoset-matrix composites with little attention towards thermoplastic ones. Conversely, these thermoplastic composites are becoming ever more attractive to the aeronautical sector. Their main advantage lies in the possibility of modifying their interface strength by adjusting the composition of the matrix. However, for a proper exploitation of new materials it is necessary to detail their characterization. The purpose of the present paper is to focus on the use of infrared thermography (IRT) to gain information on the behaviour of thermoplastic composites under impact. In addition, attention is given to image processing algorithms with the aim of more effectively measuring the extension of the impact-affected area.4

  9. Phased array beamforming and imaging in composite laminates using guided waves

    NASA Astrophysics Data System (ADS)

    Tian, Zhenhua; Leckey, Cara A. C.; Yu, Lingyu

    2016-04-01

    This paper presents the phased array beamforming and imaging using guided waves in anisotropic composite laminates. A generic phased array beamforming formula is presented, based on the classic delay-and-sum principle. The generic formula considers direction-dependent guided wave properties induced by the anisotropic material properties of composites. Moreover, the array beamforming and imaging are performed in frequency domain where the guided wave dispersion effect has been considered. The presented phased array method is implemented with a non-contact scanning laser Doppler vibrometer (SLDV) to detect multiple simulated defects at different locations in an anisotropic composite plate. The array is constructed of scan points in a small area rapidly scanned by the SLDV. Using the phased array method, multiple simulated defects at different locations are successfully detected. Our study shows that the guided wave phased array method is a potential effective method for rapid inspection of large composite structures.

  10. The colour of the dark side of the Moon

    NASA Astrophysics Data System (ADS)

    Thejll, P.; Flynn, C.; Gleisner, H.; Andersen, T.; Ulla, A.; O-Petersen, M.; Darudi, A.; Schwarz, H.

    2014-03-01

    Aims: "Earthshine" is the dim light seen on the otherwise dark side of the Moon, particularly when it is close to new. "Earthlight", or reflected sunlight from the Earth, is the source of Earthshine. Using B and V band CCD images of both the dark and bright sides of the Moon, we aim to estimate the Johnson photometry B - V colour of the Earthshine for the first time since the late 1960s. From these measurements we are also able to quantify the colour of Earthlight. Methods: We present images of the Moon taken with a small refractor in Hawaii, in B and V bands and taken under favourable conditions so that scattered light in both bands almost completely cancels, yielding a map of the surface in B - V colour. Co-addition of 100 such images taken in rapid succession substantially improves the signal-to- noise ratio, and several sources of photometric bias are eliminated by use of relative methods. Results: The earthlit dark side of the Moon is observed to be 0.150 ± 0.005 mag bluer in B - V than the sunlit bright side, in good agreement with the only known previous measurement of this quantity from 1967. Arguing on the basis of the change in B - V for sunlight reflected once off the Moon, we derive a colour for earthlight of B - V = 0.44 ± 0.02 mag (without applying a small, uncertain, phase-dependent reddening correction). The absence of a colour-gradient in the B - V image implies that the scattering properties of the atmosphere+optical system are almost exactly matched in the two wavelength bands, the consequences of which are discussed.

  11. Structural colour in Chondrus crispus.

    PubMed

    Chandler, Chris J; Wilts, Bodo D; Vignolini, Silvia; Brodie, Juliet; Steiner, Ullrich; Rudall, Paula J; Glover, Beverley J; Gregory, Thomas; Walker, Rachel H

    2015-01-01

    The marine world is incredibly rich in brilliant and intense colours. Photonic structures are found in many different species and provide extremely complex optical responses that cannot be achieved solely by pigments. In this study we examine the cuticular structure of the red alga Chondrus crispus (Irish Moss) using anatomical and optical approaches. We experimentally measure the optical response of the multilayer structure in the cuticle. Using finite-difference time-domain modelling, we demonstrate conclusively for the first time that the dimensions and organisation of lamellae are responsible for the blue structural colouration on the surface of the fronds. Comparison of material along the apical-basal axis of the frond demonstrates that structural colour is confined to the tips of the thalli and show definitively that a lack of structural colour elsewhere corresponds with a reduction in the number of lamellae and the regularity of their ordering. Moreover, by studying the optical response for different hydration conditions, we demonstrate that the cuticular structure is highly porous and that the presence of water plays a critical role in its ability to act as a structural light reflector. PMID:26139470

  12. The colour of fossil feathers.

    PubMed

    Vinther, Jakob; Briggs, Derek E G; Prum, Richard O; Saranathan, Vinodkumar

    2008-10-23

    Feathers are complex integumentary appendages of birds and some other theropod dinosaurs. They are frequently coloured and function in camouflage and display. Previous investigations have concluded that fossil feathers are preserved as carbonized traces composed of feather-degrading bacteria. Here, an investigation of a colour-banded feather from the Lower Cretaceous Crato Formation of Brazil revealed that the dark bands are preserved as elongate, oblate carbonaceous bodies 1-2 microm long, whereas the light bands retain only relief traces on the rock matrix. Energy dispersive X-ray analysis showed that the dark bands preserve a substantial amount of carbon, whereas the light bands show no carbon residue. Comparison of these oblate fossil bodies with the structure of black feathers from a living bird indicates that they are the eumelanin-containing melanosomes. We conclude that most fossil feathers are preserved as melanosomes, and that the distribution of these structures in fossil feathers can preserve the colour pattern in the original feather. The discovery of preserved melanosomes opens up the possibility of interpreting the colour of extinct birds and other dinosaurs.

  13. Imaging methods for analyzing body composition in human obesity and cardiometabolic disease.

    PubMed

    Seabolt, Lynn A; Welch, E Brian; Silver, Heidi J

    2015-09-01

    Advances in the technological qualities of imaging modalities for assessing human body composition have been stimulated by accumulating evidence that individual components of body composition have significant influences on chronic disease onset, disease progression, treatment response, and health outcomes. Importantly, imaging modalities have provided a systematic method for differentiating phenotypes of body composition that diverge from what is considered normal, that is, having low bone mass (osteopenia/osteoporosis), low muscle mass (sarcopenia), high fat mass (obesity), or high fat with low muscle mass (sarcopenic obesity). Moreover, advances over the past three decades in the sensitivity and quality of imaging not just to discern the amount and distribution of adipose and lean tissue but also to differentiate layers or depots within tissues and cells is enhancing our understanding of distinct mechanistic, metabolic, and functional roles of body composition within human phenotypes. In this review, we focus on advances in imaging technologies that show great promise for future investigation of human body composition and how they are being used to address the pandemic of obesity, metabolic syndrome, and diabetes.

  14. Imaging methods for analyzing body composition in human obesity and cardiometabolic disease.

    PubMed

    Seabolt, Lynn A; Welch, E Brian; Silver, Heidi J

    2015-09-01

    Advances in the technological qualities of imaging modalities for assessing human body composition have been stimulated by accumulating evidence that individual components of body composition have significant influences on chronic disease onset, disease progression, treatment response, and health outcomes. Importantly, imaging modalities have provided a systematic method for differentiating phenotypes of body composition that diverge from what is considered normal, that is, having low bone mass (osteopenia/osteoporosis), low muscle mass (sarcopenia), high fat mass (obesity), or high fat with low muscle mass (sarcopenic obesity). Moreover, advances over the past three decades in the sensitivity and quality of imaging not just to discern the amount and distribution of adipose and lean tissue but also to differentiate layers or depots within tissues and cells is enhancing our understanding of distinct mechanistic, metabolic, and functional roles of body composition within human phenotypes. In this review, we focus on advances in imaging technologies that show great promise for future investigation of human body composition and how they are being used to address the pandemic of obesity, metabolic syndrome, and diabetes. PMID:26250623

  15. Underwater image quality enhancement through composition of dual-intensity images and Rayleigh-stretching.

    PubMed

    Abdul Ghani, Ahmad Shahrizan; Mat Isa, Nor Ashidi

    2014-01-01

    The quality of underwater image is poor due to the properties of water and its impurities. The properties of water cause attenuation of light travels through the water medium, resulting in low contrast, blur, inhomogeneous lighting, and color diminishing of the underwater images. This paper proposes a method of enhancing the quality of underwater image. The proposed method consists of two stages. At the first stage, the contrast correction technique is applied to the image, where the image is applied with the modified Von Kries hypothesis and stretching the image into two different intensity images at the average value with respects to Rayleigh distribution. At the second stage, the color correction technique is applied to the image where the image is first converted into hue-saturation-value (HSV) color model. The modification of the color component increases the image color performance. Qualitative and quantitative analyses indicate that the proposed method outperforms other state-of-the-art methods in terms of contrast, details, and noise reduction.

  16. Underwater image quality enhancement through composition of dual-intensity images and Rayleigh-stretching.

    PubMed

    Abdul Ghani, Ahmad Shahrizan; Mat Isa, Nor Ashidi

    2014-01-01

    The quality of underwater image is poor due to the properties of water and its impurities. The properties of water cause attenuation of light travels through the water medium, resulting in low contrast, blur, inhomogeneous lighting, and color diminishing of the underwater images. This paper proposes a method of enhancing the quality of underwater image. The proposed method consists of two stages. At the first stage, the contrast correction technique is applied to the image, where the image is applied with the modified Von Kries hypothesis and stretching the image into two different intensity images at the average value with respects to Rayleigh distribution. At the second stage, the color correction technique is applied to the image where the image is first converted into hue-saturation-value (HSV) color model. The modification of the color component increases the image color performance. Qualitative and quantitative analyses indicate that the proposed method outperforms other state-of-the-art methods in terms of contrast, details, and noise reduction. PMID:25674483

  17. Preparation of AlB sub 4 C composites for image analysis

    SciTech Connect

    Kelly, A.M.; Reiswig, R.D.; Hill, M.A.; Blumenthal, W.R.

    1990-01-01

    Composites made by infiltrating B{sub 4}C networks with aluminium, or its alloys are of interest for lightweight armor applications. Image analysis plays an important part in correlating the microstructures of such composites with their mechanical properties. Accurate image analysis requires a high degree of perfection in the metallographic preparation, which is particularly difficult where the phases present have such disparate hardness and reactivities. Two preparation procedures have been developed that produce adequate contrast and definition for analysis of key microstructural features. 8 refs., 5 figs., 1 tab.

  18. Restoration of degraded images by composite gratings in a coherent optical processor.

    NASA Technical Reports Server (NTRS)

    Jablonowski, D. P.; Lee, S. H.

    1973-01-01

    A study has been made on restoration of degraded images utilizing spatial filtering techniques in a coherent optical processor. This study differs from other coherent approaches in that the spatial filters employed contain only composite gratings that are quite simple to produce. A general method of synthesizing the appropriate composite gratings for linearly smeared as well as multiply exposed and out-of-focus images will be presented in some detail with experimental results. The extension of the method of synthesis to other types of degradation is briefly discussed.

  19. Characterization of delamination and disbonding in stratified dielectric composites by millimeter wave imaging

    SciTech Connect

    Bakhtiari, S.; Gopalsami, N.; Raptis, A.C.

    1995-04-01

    Electromagnetic radiation at microwave frequencies has been in use for nondestructive evaluation (NDE) of various low-loss and generally lossy dielectric materials. A monostatic backscatter millimeter wave imaging system was utilized for non-destructive characterization of defects in low-loss composites of Kevlar/epoxy. Defects consisting of subsurface delamination and disbonding defects were successfully detected and characterized. Images are constructed by measuring the relative amplitude and phase of the reflected radiation. The results clearly indicate the potential of such high-frequency systems for nondestructive characterization of small defects in low-loss dielectric composite materials.

  20. Damage threshold study of sonic IR imaging on carbon-fiber reinforced laminated composite materials

    NASA Astrophysics Data System (ADS)

    Han, Xiaoyan; He, Qi; Zhang, Ding; Ashbaugh, Mike; Favro, Lawrence D.; Newaz, Golam; Thomas, Robert L.

    2013-01-01

    Sonic Infrared Imaging, as a young NDE technology, has drawn a lot of attentions due to it's fast, wide-area evaluation capability, and due to its broad applications in different materials such as metal/metal alloy, composites and detection of various types of defects: surface, subsurface, cracks, delaminations/disbonds. Sonic IR Imaging combines pulsed ultrasound excitation and infrared imaging to detect defects in materials. The sound pulse causes rubbing due to non-unison motion between faces of defects, and infrared sensors image the temperature map over the target to identify defects. However, concerns have also been brought up about possible damages which might occur at the contact spots between the ultrasound transducer from the external excitation source and the target materials. In this paper, we present our results from a series of systematically designed experiments on carbon-fiber reinforced laminated composite panels to address the concerns.

  1. A new optical image encryption method based on multi-beams interference and vector composition

    NASA Astrophysics Data System (ADS)

    Chen, Linfei; Liu, Jingyu; Wen, Jisen; Gao, Xiong; Mao, Haidan; Shi, Xiaoyan; Qu, Qingling

    2015-06-01

    In this paper, a new method for optical image encryption based on multi-beams interference principle and vector composition is proposed. In this encryption, the original image is encoded into n-1 phase only masks which are regarded as the keys of the encryption system and a ciphertext according to multi-beams interference principle and vector composition. In decryption process, n beams of parallel incident light illuminate at the phase only masks and the ciphertext, and we can obtain the decrypted image at output plane after Fourier transforms. The security of the proposed method is discussed, finding that no decrypted image can be obtained only when all the keys used are right. Furthermore, the keys can be stored separately resulting in improving the security of encryption system. Computer simulation results are presented to verify the validity of the proposed method.

  2. A novel Bayesian imaging method for probabilistic delamination detection of composite materials

    NASA Astrophysics Data System (ADS)

    Peng, Tishun; Saxena, Abhinav; Goebel, Kai; Xiang, Yibing; Sankararaman, Shankar; Liu, Yongming

    2013-12-01

    A probabilistic framework for location and size determination for delamination in carbon-carbon composites is proposed in this paper. A probability image of delaminated area using Lamb wave-based damage detection features is constructed with the Bayesian updating technique. First, the algorithm for the probabilistic delamination detection framework using the proposed Bayesian imaging method (BIM) is presented. Next, a fatigue testing setup for carbon-carbon composite coupons is described. The Lamb wave-based diagnostic signal is then interpreted and processed. Next, the obtained signal features are incorporated in the Bayesian imaging method for delamination size and location detection, as well as the corresponding uncertainty bounds prediction. The damage detection results using the proposed methodology are compared with x-ray images for verification and validation. Finally, some conclusions are drawn and suggestions made for future works based on the study presented in this paper.

  3. Relationships Between Body Image, Body Composition, Sexual Functioning, and Sexual Satisfaction Among Heterosexual Young Adults.

    PubMed

    Milhausen, Robin R; Buchholz, Andrea C; Opperman, Emily A; Benson, Lindsay E

    2015-08-01

    This study investigated the association between body image and body-image self-consciousness on sexual satisfaction, accounting for relationships between body fat and body image, and between sexual functioning and sexual satisfaction, while controlling for relationship satisfaction. Participants were 143, 18-25 year-old Caucasian men and women in heterosexual monogamous relationships, recruited from the University of Guelph and surrounding community in Ontario, Canada. Various domains of body image, body-image self-consciousness, sexual satisfaction and functioning, and relationship satisfaction data were collected by questionnaires. Body fat was measured using dual energy X-ray absorptiometry. Among men, body image was positively associated with sexual satisfaction, after controlling for relationship satisfaction. Men with greater body fat were more likely to have poorer behavioral and affective body image. Only body image specific to the sexual encounter influenced sexual functioning. Among women, no domain of body image was associated with sexual satisfaction, after controlling for relationship satisfaction. Women with greater body fat were more likely to have poorer affective and sexual-encounter-specific body image. As percent total fat increased, sexual functioning decreased. Our results suggest a complex pattern of relationships exists among body image and body composition constructs and sexual and relationship variable; and that these relationships are not the same for men and women.

  4. Hair colouring, permanent styling and hair structure.

    PubMed

    Harrison, S; Sinclair, R

    2003-07-01

    Hair is an important component of body image and has immense psychological importance for both men and women. Women, in particular, over the ages have modified their appearance through changing their hair colour or style. Hair can be straight, wavy or curly, blonde, black, brown or red. These natural variations are an important part of our identity that can be manipulated according to the dictates of fashion, culture or society. Different types of hair have varying affinity for the different colouring and waving methods. Damaged hair also has a different affinity for hair products than normal healthy hair. The hair shaft is remarkably strong and resistant to the extremes of nature. Hair cosmetics are widely available and manipulate the structural properties of hair. Whilst most procedures are safe, there is considerable potential for damage to the hair and hair problems of acute onset, including hair breakage, hair loss and loss of condition, are frequently blamed on the last product used on the hair. Hair problems are particularly prevalent among people who repeatedly alter the natural style of their hair.

  5. Tomographic Imaging of Glass/Epoxy Composite with a Laser Based Ultrasonics Setup

    SciTech Connect

    Khanna, N.; Raghuram, V.; Munshi, P.; Kishore, N. N.; Arnold, W.

    2008-09-26

    The present work is an attempt to augment the classical laser-based-ultrasonics setup for tomographic imaging purposes. A Glass/epoxy composite with steel insert is the test specimen and time-of-flight data has been used for tomographic reconstruction. Multiplicative algebraic reconstruction technique is used for this limited-view experiment. The resulting image is able to bring out the strong metal features.

  6. Marriage Strategy of Structure and Composition Designs for Intensifying Ultrasound & MR & CT Trimodal Contrast Imaging.

    PubMed

    Zhang, Kun; Chen, Hangrong; Li, Pei; Bo, Xiaowan; Li, Xiaolong; Zeng, Zeng; Xu, Huixiong

    2015-08-26

    Despite great efforts having been devoted to the design of multimodal imaging probe, almost all design principles of nanotheranostic agents subordinate to simple assemblies of building blocks, resulting in complex preparation process and discounted ability, that is, 1 + 1 < 2. In this report, a novel design strategy, marriage of structure design and composition design that can maximize imaging ability of each building block, ultimately achieving 1 + 1 ≥ 2, has been established. Moreover, a high-efficient ultrasound (US) & MR & CT trimodal contrast agent acts as model to instantiate this design strategy, wherein nanoparticles-induced nonlinear scattering and rattle-type structure-induced double scattering enhancing US imaging, and uniform distribution of Mn(2+) paramagentic centers and "core-satellite" structure of Au atoms favoring enhanced MR imaging and CT imaging, respectively have been validated, achieving optimization of structure design. Importantly, the selected components, silica, Au and MnO are endowed with excellent biocompatibility, displaying the marriage strategy of composition design with aforementioned structure optimization. In in vivo evaluations, such a biocompatible trimodal probe is demonstrated of excellent performance in intensifying CT, MR and US imaging in vivo, especially after positively charged modification by PEI promoting more probes retained in tumor. More importantly, as a universal design strategy, the involved principles in constructing such a US&MR&CT trimodal imaging probe promise great potentials in guiding designs of other materials-based multimodal imaging probe. PMID:26245739

  7. Marriage Strategy of Structure and Composition Designs for Intensifying Ultrasound & MR & CT Trimodal Contrast Imaging.

    PubMed

    Zhang, Kun; Chen, Hangrong; Li, Pei; Bo, Xiaowan; Li, Xiaolong; Zeng, Zeng; Xu, Huixiong

    2015-08-26

    Despite great efforts having been devoted to the design of multimodal imaging probe, almost all design principles of nanotheranostic agents subordinate to simple assemblies of building blocks, resulting in complex preparation process and discounted ability, that is, 1 + 1 < 2. In this report, a novel design strategy, marriage of structure design and composition design that can maximize imaging ability of each building block, ultimately achieving 1 + 1 ≥ 2, has been established. Moreover, a high-efficient ultrasound (US) & MR & CT trimodal contrast agent acts as model to instantiate this design strategy, wherein nanoparticles-induced nonlinear scattering and rattle-type structure-induced double scattering enhancing US imaging, and uniform distribution of Mn(2+) paramagentic centers and "core-satellite" structure of Au atoms favoring enhanced MR imaging and CT imaging, respectively have been validated, achieving optimization of structure design. Importantly, the selected components, silica, Au and MnO are endowed with excellent biocompatibility, displaying the marriage strategy of composition design with aforementioned structure optimization. In in vivo evaluations, such a biocompatible trimodal probe is demonstrated of excellent performance in intensifying CT, MR and US imaging in vivo, especially after positively charged modification by PEI promoting more probes retained in tumor. More importantly, as a universal design strategy, the involved principles in constructing such a US&MR&CT trimodal imaging probe promise great potentials in guiding designs of other materials-based multimodal imaging probe.

  8. Colour Vision Deficiency and Physics Teaching

    ERIC Educational Resources Information Center

    Maule, Louise; Featonby, David

    2016-01-01

    1 in 12 males suffer from some form of colour vision deficiency (CVD) which in the present colour dominated world of education presentation can be a severe disadvantage. Although aware of "colourblindness" most teachers make little or no adjustment for these pupils for whom tasks may be more difficult. This article examines colour vision…

  9. Biological Components of Colour Preference in Infancy

    ERIC Educational Resources Information Center

    Franklin, Anna; Bevis, Laura; Ling, Yazhu; Hurlbert, Anya

    2010-01-01

    Adult colour preference has been summarized quantitatively in terms of weights on the two fundamental neural processes that underlie early colour encoding: the S-(L+M) ("blue-yellow") and L-M ("red-green") cone-opponent contrast channels ( Ling, Hurlbert & Robinson, 2006; Hurlbert & Ling, 2007). Here, we investigate whether colour preference in…

  10. An RGB Approach to Prismatic Colours

    ERIC Educational Resources Information Center

    Theilmann, Florian; Grusche, Sascha

    2013-01-01

    Teaching prismatic colours usually boils down to establishing the take-home message that white light consists of "differently refrangible" coloured rays. This approach explains the classical spectrum of seven colours but has its limitations, e.g. in discussing spectra from setups with higher resolution or in understanding the well…

  11. Effect of the glandular composition on digital breast tomosynthesis image quality and dose optimisation.

    PubMed

    Marques, T; Ribeiro, A; Di Maria, S; Belchior, A; Cardoso, J; Matela, N; Oliveira, N; Janeiro, L; Almeida, P; Vaz, P

    2015-07-01

    In the image quality assessment for digital breast tomosynthesis (DBT), a breast phantom with an average percentage of 50 % glandular tissue is seldom used, which may not be representative of the breast tissue composition of the women undergoing such examination. This work aims at studying the effect of the glandular composition of the breast on the image quality taking into consideration different sizes of lesions. Monte Carlo simulations were performed using the state-of-the-art computer program PENELOPE to validate the image acquisition system of the DBT equipment as well as to calculate the mean glandular dose for each projection image and for different breast compositions. The integrated PENELOPE imaging tool (PenEasy) was used to calculate, in mammography, for each clinical detection task the X-ray energy that maximises the figure of merit. All the 2D cranial-caudal projections for DBT were simulated and then underwent the reconstruction process applying the Simultaneous Algebraic Reconstruction Technique. Finally, through signal-to-noise ratio analysis, the image quality in DBT was assessed. PMID:25836692

  12. Effect of the glandular composition on digital breast tomosynthesis image quality and dose optimisation.

    PubMed

    Marques, T; Ribeiro, A; Di Maria, S; Belchior, A; Cardoso, J; Matela, N; Oliveira, N; Janeiro, L; Almeida, P; Vaz, P

    2015-07-01

    In the image quality assessment for digital breast tomosynthesis (DBT), a breast phantom with an average percentage of 50 % glandular tissue is seldom used, which may not be representative of the breast tissue composition of the women undergoing such examination. This work aims at studying the effect of the glandular composition of the breast on the image quality taking into consideration different sizes of lesions. Monte Carlo simulations were performed using the state-of-the-art computer program PENELOPE to validate the image acquisition system of the DBT equipment as well as to calculate the mean glandular dose for each projection image and for different breast compositions. The integrated PENELOPE imaging tool (PenEasy) was used to calculate, in mammography, for each clinical detection task the X-ray energy that maximises the figure of merit. All the 2D cranial-caudal projections for DBT were simulated and then underwent the reconstruction process applying the Simultaneous Algebraic Reconstruction Technique. Finally, through signal-to-noise ratio analysis, the image quality in DBT was assessed.

  13. New insights into subsurface imaging of carbon nanotubes in polymer composites via scanning electron microscopy

    NASA Astrophysics Data System (ADS)

    Zhao, Minhua; Ming, Bin; Kim, Jae-Woo; Gibbons, Luke J.; Gu, Xiaohong; Nguyen, Tinh; Park, Cheol; Lillehei, Peter T.; Villarrubia, J. S.; Vladár, András E.; Liddle, J. Alexander

    2015-02-01

    Despite many studies of subsurface imaging of carbon nanotube (CNT)-polymer composites via scanning electron microscopy (SEM), significant controversy exists concerning the imaging depth and contrast mechanisms. We studied CNT-polyimide composites and, by three-dimensional reconstructions of captured stereo-pair images, determined that the maximum SEM imaging depth was typically hundreds of nanometers. The contrast mechanisms were investigated over a broad range of beam accelerating voltages from 0.3 to 30 kV, and ascribed to modulation by embedded CNTs of the effective secondary electron (SE) emission yield at the polymer surface. This modulation of the SE yield is due to non-uniform surface potential distribution resulting from current flows due to leakage and electron beam induced current. The importance of an external electric field on SEM subsurface imaging was also demonstrated. The insights gained from this study can be generally applied to SEM nondestructive subsurface imaging of conducting nanostructures embedded in dielectric matrices such as graphene-polymer composites, silicon-based single electron transistors, high resolution SEM overlay metrology or e-beam lithography, and have significant implications in nanotechnology.

  14. Composite low-coherence interferometer for imaging of immersed tissue with high accuracy

    NASA Astrophysics Data System (ADS)

    Chang, Chun-Wei; Hsu, I.-Jen

    2012-09-01

    Imaging and measurement of the surface profile of an object with high resolution has become essential in both of biological research and industry application. Many samples under investigation such as cultured cells are usually immersed in liquid. Although the techniques such as scanning electron microscope and atomic force microscope can provide imaging or measurement of the surface profile with nanometer resolution, it is difficult for them to image an immersed object with their typical types. Recently, we have proposed and demonstrated a new technique based on composite interferometer which can perform imaging and measurement of the surface profile of an object with accuracy in the axial direction within 5 nm through a self-phase-compensation mechanism. In this research, an optical system based on the concept of combination of optical coherence microscopy (OCM) and composite interferometer was built for imaging of biological tissue immersed in water with axial accuracy at nanometer scale. In the system, a Ti:sapphire laser with center wavelength at 800 nm and spectral width of 140 nm was used as the light source. The composite interferometer comprises two Michelson interferometers sharing common light source, reference arm and photodetector. One of the two interferometers served as a typical OCM system and the other was used to measure the phase shift in the reference arm in each axial scan with the sample being a fixed reflection mirror. The system was used to image the surface profiles of various immersed biological samples with accuracy at nanometer scale through the self-phasecompensation mechanism.

  15. Genetic and environmental effects influencing fruit colour and QTL analysis in raspberry.

    PubMed

    McCallum, Susan; Woodhead, Mary; Hackett, Christine A; Kassim, Angzzas; Paterson, Alistair; Graham, Julie

    2010-08-01

    Raspberry (Rubus idaeus) fruit colour was assessed in the Latham x Glen Moy mapping population using a colour meter and visual scores over three seasons and three environments. The colour measurements were found to be significantly associated with pigment content, have high heritability, and stable QTL were identified across environments and seasons. Anthocyanin content has previously been shown to be the major contributor to fruit colour in red raspberry. Major structural genes (F3'H, FLS, DFR, IFR, OMT and GST) and transcription factors (bZIP, bHLH and MYB) influencing flavonoid biosynthesis have been identified, mapped and shown to underlie QTL for quantitative and qualitative anthocyanin composition. Favourable alleles for the selected traits were identified for the aspects of fruit colour and partitioning of individual pigments.

  16. Colour annealing - a toy model of colour reconnections

    SciTech Connect

    Sandhoff, Marisa; Skands, Peter; /Fermilab

    2005-12-01

    We present a simple toy model for colour reconnections at the nonperturbative level. The model resembles an annealing-type algorithm and is applicable to any collider and process type, though we argue for a possible enhancement of the effect in hadron-hadron collisions. We present a simple application and study of the consequences for semileptonic t{bar t} events at the Tevatron.

  17. Plexus structure imaging with thin slab MR neurography: rotating frames, fly-throughs, and composite projections

    NASA Astrophysics Data System (ADS)

    Raphael, David T.; McIntee, Diane; Tsuruda, Jay S.; Colletti, Patrick; Tatevossian, Raymond; Frazier, James

    2006-03-01

    We explored multiple image processing approaches by which to display the segmented adult brachial plexus in a three-dimensional manner. Magnetic resonance neurography (MRN) 1.5-Tesla scans with STIR sequences, which preferentially highlight nerves, were performed in adult volunteers to generate high-resolution raw images. Using multiple software programs, the raw MRN images were then manipulated so as to achieve segmentation of plexus neurovascular structures, which were incorporated into three different visualization schemes: rotating upper thoracic girdle skeletal frames, dynamic fly-throughs parallel to the clavicle, and thin slab volume-rendered composite projections.

  18. Frequential versus spatial colour textons for breast TMA classification.

    PubMed

    Fernández-Carrobles, M Milagro; Bueno, Gloria; Déniz, Oscar; Salido, Jesús; García-Rojo, Marcial; Gonzández-López, Lucía

    2015-06-01

    Advances in digital pathology are generating huge volumes of whole slide (WSI) and tissue microarray images (TMA) which are providing new insights into the causes of cancer. The challenge is to extract and process effectively all the information in order to characterize all the heterogeneous tissue-derived data. This study aims to identify an optimal set of features that best separates different classes in breast TMA. These classes are: stroma, adipose tissue, benign and benign anomalous structures and ductal and lobular carcinomas. To this end, we propose an exhaustive assessment on the utility of textons and colour for automatic classification of breast TMA. Frequential and spatial texton maps from eight different colour models were extracted and compared. Then, in a novel way, the TMA is characterized by the 1st and 2nd order Haralick statistical descriptors obtained from the texton maps with a total of 241 × 8 features for each original RGB image. Subsequently, a feature selection process is performed to remove redundant information and therefore to reduce the dimensionality of the feature vector. Three methods were evaluated: linear discriminant analysis, correlation and sequential forward search. Finally, an extended bank of classifiers composed of six techniques was compared, but only three of them could significantly improve accuracy rates: Fisher, Bagging Trees and AdaBoost. Our results reveal that the combination of different colour models applied to spatial texton maps provides the most efficient representation of the breast TMA. Specifically, we found that the best colour model combination is Hb, Luv and SCT for all classifiers and the classifier that performs best for all colour model combinations is the AdaBoost. On a database comprising 628 TMA images, classification yields an accuracy of 98.1% and a precision of 96.2% with a total of 316 features on spatial textons maps.

  19. Opening up a Colourful Cosmic Jewel Box

    NASA Astrophysics Data System (ADS)

    2009-10-01

    The combination of images taken by three exceptional telescopes, the ESO Very Large Telescope on Cerro Paranal , the MPG/ESO 2.2-metre telescope at ESO's La Silla observatory and the NASA/ESA Hubble Space Telescope, has allowed the stunning Jewel Box star cluster to be seen in a whole new light. Star clusters are among the most visually alluring and astrophysically fascinating objects in the sky. One of the most spectacular nestles deep in the southern skies near the Southern Cross in the constellation of Crux. The Kappa Crucis Cluster, also known as NGC 4755 or simply the "Jewel Box" is just bright enough to be seen with the unaided eye. It was given its nickname by the English astronomer John Herschel in the 1830s because the striking colour contrasts of its pale blue and orange stars seen through a telescope reminded Herschel of a piece of exotic jewellery. Open clusters [1] such as NGC 4755 typically contain anything from a few to thousands of stars that are loosely bound together by gravity. Because the stars all formed together from the same cloud of gas and dust their ages and chemical makeup are similar, which makes them ideal laboratories for studying how stars evolve. The position of the cluster amongst the rich star fields and dust clouds of the southern Milky Way is shown in the very wide field view generated from the Digitized Sky Survey 2 data. This image also includes one of the stars of the Southern Cross as well as part of the huge dark cloud of the Coal Sack [2]. A new image taken with the Wide Field Imager (WFI) on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile shows the cluster and its rich surroundings in all their multicoloured glory. The large field of view of the WFI shows a vast number of stars. Many are located behind the dusty clouds of the Milky Way and therefore appear red [3]. The FORS1 instrument on the ESO Very Large Telescope (VLT) allows a much closer look at the cluster itself. The telescope's huge mirror

  20. Differentiating Biological Colours with Few and Many Sensors: Spectral Reconstruction with RGB and Hyperspectral Cameras

    PubMed Central

    Garcia, Jair E.; Girard, Madeline B.; Kasumovic, Michael; Petersen, Phred; Wilksch, Philip A.; Dyer, Adrian G.

    2015-01-01

    Background The ability to discriminate between two similar or progressively dissimilar colours is important for many animals as it allows for accurately interpreting visual signals produced by key target stimuli or distractor information. Spectrophotometry objectively measures the spectral characteristics of these signals, but is often limited to point samples that could underestimate spectral variability within a single sample. Algorithms for RGB images and digital imaging devices with many more than three channels, hyperspectral cameras, have been recently developed to produce image spectrophotometers to recover reflectance spectra at individual pixel locations. We compare a linearised RGB and a hyperspectral camera in terms of their individual capacities to discriminate between colour targets of varying perceptual similarity for a human observer. Main Findings (1) The colour discrimination power of the RGB device is dependent on colour similarity between the samples whilst the hyperspectral device enables the reconstruction of a unique spectrum for each sampled pixel location independently from their chromatic appearance. (2) Uncertainty associated with spectral reconstruction from RGB responses results from the joint effect of metamerism and spectral variability within a single sample. Conclusion (1) RGB devices give a valuable insight into the limitations of colour discrimination with a low number of photoreceptors, as the principles involved in the interpretation of photoreceptor signals in trichromatic animals also apply to RGB camera responses. (2) The hyperspectral camera architecture provides means to explore other important aspects of colour vision like the perception of certain types of camouflage and colour constancy where multiple, narrow-band sensors increase resolution. PMID:25965264

  1. A STANDARDIZED LANTERN FOR TESTING COLOUR VISION.

    PubMed

    Martin, L C

    1939-01-01

    A Lantern for lesting Colour-Vision is arranged to show test colours in pairs as in the Board of Trade Lantern. It is adapted to use electric light, and is standardized by stringent testing. The paper discusses the experiments and considerations which led to the formulation of the allowable tolerances in the transmission and colour co-ordinate specifications of the filters, the colour temperature of the lamps and so on. The results of tests on normal and colour-defective subjects are described.

  2. Thermal imaging and air-coupled ultrasound characterization of a continuous-fiber ceramic composite panels.

    SciTech Connect

    Sun, J. G.; Easler, T. E.; Szweda, A.; Pillai, T. A. K.; Deemer, C.; Ellingson, W. A.

    1998-04-01

    SYLRAMIC{trademark} continuous fiber ceramic-matrix composites (Nicalon{trademark} fiber/SiNC matrix) were fabricated by Dow Corning Corporation with the polymer-impregnation and pyrolysis (PIP) process. The composite microstructure and its uniformity, and the completeness of infiltration during processing were studied as a function of number of PIP cycles. Two nondestructive evaluation (NDE) methods, i.e., infrared thermal imaging and air-coupled ultrasound (UT), were used to investigate flat composite panels of two thicknesses and various sizes. The thermal imaging method provided two-dimensional (2D) images of through-thickness thermal diffusivity distributions, and the air-coupled UT method provided 2D images of through-thickness ultrasonic transmission of the panel components. Results from both types of NDEs were compared at various PIP cycles during fabrication of the composites. A delaminated region was clearly detected and its progressive repair was monitored during processing. The NDE data were also correlated to results obtained from destructive characterization.

  3. Blind image analysis for the compositional and structural characterization of plant cell walls.

    PubMed

    Perera, Pradeep N; Schmidt, Martin; Schuck, P James; Adams, Paul D

    2011-09-30

    A new image analysis strategy is introduced to determine the composition and the structural characteristics of plant cell walls by combining Raman microspectroscopy and unsupervised data mining methods. The proposed method consists of three main steps: spectral preprocessing, spatial clustering of the image and finally estimation of spectral profiles of pure components and their weights. Point spectra of Raman maps of cell walls were preprocessed to remove noise and fluorescence contributions and compressed with PCA. Processed spectra were then subjected to k-means clustering to identify spatial segregations in the images. Cell wall images were reconstructed with cluster identities and each cluster was represented by the average spectrum of all the pixels in the cluster. Pure components spectra were estimated by spectral entropy minimization criteria with simulated annealing optimization. Two pure spectral estimates that represent lignin and carbohydrates were recovered and their spatial distributions were calculated. Our approach partitioned the cell walls into many sublayers, based on their composition, thus enabling composition analysis at subcellular levels. It also overcame the well known problem that native lignin spectra in lignocellulosics have high spectral overlap with contributions from cellulose and hemicelluloses, thus opening up new avenues for microanalyses of monolignol composition of native lignin and carbohydrates without chemical or mechanical extraction of the cell wall materials.

  4. Can Imageability Help Us Draw the Line between Storage and Composition?

    ERIC Educational Resources Information Center

    Prado, Elizabeth L.; Ullman, Michael T.

    2009-01-01

    Language requires both storage and composition. However, exactly what is retrieved from memory and what is assembled remains controversial, especially for inflected words. Here, "imageability effects" is introduced as a new diagnostic of storage and a complement to frequency effects. In 2 studies of past-tense morphology, more reliable…

  5. Strategies for Prompt Searches for GRB Afterglows: The Discovery of GRB 001011 Optical/Near-Infrared Counterpart Using Colour-Colour Selection

    NASA Technical Reports Server (NTRS)

    Gorosabel, J.; Fynbo, J. U.; Hjorth, J.; Wolf, C.; Andersen, M. I.; Pedersen, H.; Christensen, L.; Jensen, B. L.; Moller, P.; Afonso, J.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    We report the discovery of the optical and near-infrared counterpart to GRB 001011. The GRB 001011 error box determined by Beppo-SAX was simultaneously imaged in the near-infrared by the 3.58-m. New Technology Telescope and in the optical by the 1.54-m Danish Telescope - 8 hr after the gamma-ray event. We implement the colour-colour discrimination technique proposed by Rhoads (2001) and extend it using near-IR data as well. We present the results provided by an automatic colour-colour discrimination pipe-line developed to discern the different populations of objects present in the GRB 001011 error box. Our software revealed three candidates based on single-epoch images. Second-epoch observations carried out approx. 3.2 days after the burst revealed that the most likely candidate had faded thus identifying it with the counterpart to the GRB. In deep R-band images obtained 7 months after the burst a faint (R=25.38 plus or minus 0.25) elongated object, presumably the host galaxy of GRB 001011, was detected at the position of the afterglow. The GRB 001011 afterglow is the first discovered with the assistance of colour-colour diagram techniques. We discuss the advantages of using this method and its application to boxes determined by future missions.

  6. The neural correlate of colour distances revealed with competing synaesthetic and real colours.

    PubMed

    Laeng, Bruno; Hugdahl, Kenneth; Specht, Karsten

    2011-03-01

    Synaesthetes claim to perceive illusory colours when reading alphanumeric symbols so that two colours are said to be bound to the same letter or digit (i.e., the colour of the ink, e.g., black, and an additional, synaesthetic, colour). To explore the neural correlates of this phenomenon, we used a Stroop single-letter colour-naming task and found that distances in colour space between the illusory and real colours of a letter target (as computed from either the RGB or CIExyY coordinates of colours) systematically influenced the degree of neuronal activation in colour-processing brain regions. The synaesthetes also activated the same fronto-parietal network during the classic colour-word Stroop task and single-letter tasks. We conclude that the same neural substrate that supports the conscious experience of colour, as triggered by physical wavelength, supports the experience of synaesthetic colours. Thus, two colour attributes (one that is wavelength-dependent and one that is illusory) can be bound to the same stimulus position and simultaneously engage the colour areas in proportion to their similarity in colour space.

  7. Characterisation of the n-colour printing process using the spot colour overprint model.

    PubMed

    Deshpande, Kiran; Green, Phil; Pointer, Michael R

    2014-12-29

    This paper is aimed at reproducing the solid spot colours using the n-colour separation. A simplified numerical method, called as the spot colour overprint (SCOP) model, was used for characterising the n-colour printing process. This model was originally developed for estimating the spot colour overprints. It was extended to be used as a generic forward characterisation model for the n-colour printing process. The inverse printer model based on the look-up table was implemented to obtain the colour separation for n-colour printing process. Finally the real-world spot colours were reproduced using 7-colour separation on lithographic offset printing process. The colours printed with 7 inks were compared against the original spot colours to evaluate the accuracy. The results show good accuracy with the mean CIEDE2000 value between the target colours and the printed colours of 2.06. The proposed method can be used successfully to reproduce the spot colours, which can potentially save significant time and cost in the printing and packaging industry.

  8. BOREAS RSS-7 Regional LAI and FPAR Images From 10-Day AVHRR-LAC Composites

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Chen, Jing; Cihlar, Josef

    2000-01-01

    The BOReal Ecosystem-Atmosphere Study Remote Sensing Science (BOREAS RSS-7) team collected various data sets to develop and validate an algorithm to allow the retrieval of the spatial distribution of Leaf Area Index (LAI) from remotely sensed images. Advanced Very High Resolution Radiometer (AVHRR) level-4c 10-day composite Normalized Difference Vegetation Index (NDVI) images produced at CCRS were used to produce images of LAI and the Fraction of Photosynthetically Active Radiation (FPAR) absorbed by plant canopies for the three summer IFCs in 1994 across the BOREAS region. The algorithms were developed based on ground measurements and Landsat Thematic Mapper (TM) images. The data are stored in binary image format files.

  9. Evidence against functionalism from neuroimaging of the alien colour effect in synaesthesia.

    PubMed

    Gray, Jeffrey A; Parslow, David M; Brammer, Michael J; Chopping, Susan; Vythelingum, Goparlen N; ffytche, Dominic H

    2006-02-01

    Coloured hearing synaesthetes experience colours to heard words, as confirmed by reliability of self-report, psychophysical testing and functional neuroimaging data. Some also describe the 'alien colour effect' (ACE): in response to colour names, they experience colours different from those named. We have previously reported that the ACE slows colour naming in a Stroop task, reflecting cognitive interference from synaesthetically induced colours, which depends upon their being consciously experienced. It has been proposed that the hippocampus mediates such consciously experienced conflict. Consistent with this hypothesis, we now report that, in functional magnetic resonance imaging of the Stroop task, hippocampal activation differentiates synaesthetes with the ACE from those without it and from non-synaesthete controls. These findings confirm the reality of coloured hearing synaesthesia and the ACE, phenomena which pose major challenges to the dominant contemporary account of mental states, functionalism. Reductive functionalism identifies types of mental states with causal roles: relations to inputs, outputs and other states. However, conscious mental states, such as experiences of colour, are distinguished by their qualitative properties or qualia. If functionalism is applied to conscious mental states, it identifies the qualitative type of an experience with its causal role or function. This entails both that experiences with disparate qualitative properties cannot have the same functional properties, and that experiences with disparate functional properties cannot have the same qualitative properties. Challenges to functionalism have often denied the first entailment. Here, we challenge the second entailment on empirical grounds. In coloured hearing synaesthesia, colour qualia are associated with both hearing words and seeing surfaces; and, in the ACE, these two functions act in opposition to one another. Whatever its merits as an account of other mental states

  10. Characterising the composition of waste-derived fuels using a novel image analysis tool.

    PubMed

    Peddireddy, S; Longhurst, P J; Wagland, S T

    2015-06-01

    An experimental study was completed using a previously developed and innovative image analysis approach, which has been applied here to shredded waste materials representative of waste-derived fuels. Waste components were collected from source-segregated recycling containers and shredded to <150 mm. These materials were then used to produce 3× samples of different composition. The samples were spread to represent materials on a conveyor belt, and multiple images of each sample were captured using 10×10 cm and 20×20 cm quadrats. The images were processed using ERDAS Imagine software to determine the area covered by each waste component. This coverage was converted into a mass using density data determined as part of this study, yielding a determined composition which was then compared with the known composition of the samples. The image analysis results indicated a strong correlation with the actual values (mean r=0.89). The area coverage of the sample (10×10 cm or 20×20 cm) contributes to the accuracy as the dot-grid approach used with the particle size within the samples may result in components not being sufficiently monitored. This manuscript presents initial results of the application of an adapted innovative image-based method, and critically assesses how the technique could be improved and developed in the future. PMID:25827256

  11. A quantitative damage imaging technique based on enhanced CCRTM for composite plates using 2D scan

    NASA Astrophysics Data System (ADS)

    He, Jiaze; Yuan, Fuh-Gwo

    2016-10-01

    A two-dimensional (2D) non-contact areal scan system was developed to image and quantify impact damage in a composite plate using an enhanced zero-lag cross-correlation reverse-time migration (E-CCRTM) technique. The system comprises a single piezoelectric wafer mounted on the composite plate and a laser Doppler vibrometer (LDV) for scanning a region in the vicinity of the PZT to capture the scattered wavefield. The proposed damage imaging technique takes into account the amplitude, phase, geometric spreading, and all of the frequency content of the Lamb waves propagating in the plate; thus, a reflectivity coefficients of the delamination is calculated and potentially related to damage severity. Comparisons are made in terms of damage imaging quality between 2D areal scans and 1D line scans as well as between the proposed and existing imaging conditions. The experimental results show that the 2D E-CCRTM performs robustly when imaging and quantifying impact damage in large-scale composites using a single PZT actuator with a nearby areal scan using LDV.

  12. Evolution of colour vision in mammals.

    PubMed

    Jacobs, Gerald H

    2009-10-12

    Colour vision allows animals to reliably distinguish differences in the distributions of spectral energies reaching the eye. Although not universal, a capacity for colour vision is sufficiently widespread across the animal kingdom to provide prima facie evidence of its importance as a tool for analysing and interpreting the visual environment. The basic biological mechanisms on which vertebrate colour vision ultimately rests, the cone opsin genes and the photopigments they specify, are highly conserved. Within that constraint, however, the utilization of these basic elements varies in striking ways in that they appear, disappear and emerge in altered form during the course of evolution. These changes, along with other alterations in the visual system, have led to profound variations in the nature and salience of colour vision among the vertebrates. This article concerns the evolution of colour vision among the mammals, viewing that process in the context of relevant biological mechanisms, of variations in mammalian colour vision, and of the utility of colour vision.

  13. Colour discrimination and categorisation in Williams syndrome.

    PubMed

    Farran, Emily K; Cranwell, Matthew B; Alvarez, James; Franklin, Anna

    2013-10-01

    Individuals with Williams syndrome (WS) present with impaired functioning of the dorsal visual stream relative to the ventral visual stream. As such, little attention has been given to ventral stream functions in WS. We investigated colour processing, a predominantly ventral stream function, for the first time in nineteen individuals with Williams syndrome. Colour discrimination was assessed using the Farnsworth-Munsell 100 hue test. Colour categorisation was assessed using a match-to-sample test and a colour naming task. A visual search task was also included as a measure of sensitivity to the size of perceptual colour difference. Results showed that individuals with WS have reduced colour discrimination relative to typically developing participants matched for chronological age; performance was commensurate with a typically developing group matched for non-verbal ability. In contrast, categorisation was typical in WS, although there was some evidence that sensitivity to the size of perceptual colour differences was reduced in this group.

  14. Colour dependence of zodiacal light models

    NASA Technical Reports Server (NTRS)

    Giese, R. H.; Hanner, M. S.; Leinert, C.

    1973-01-01

    Colour models of the zodiacal light in the ecliptic have been calculated for both dielectric and metallic particles in the sub-micron and micron size range. Two colour ratios were computed, a blue ratio and a red ratio. The models with a size distribution proportional to s to the -2.5 power ds (where s is the particle radius) generally show a colour close to the solar colour and almost independent of elongation. Especially in the blue colour ratio there is generally no significant dependence on the lower cutoff size (0.1-1 micron). The main feature of absorbing particles is a reddening at small elongations. The models for size distributions proportional to s to the -4 power ds show larger departures from solar colour and more variation with model parameters. Colour measurements, including red and near infra-red, therefore are useful to distinguish between flat and steep size spectra and to verify the presence of slightly absorbing particles.

  15. Health & nutritional implications of food colours.

    PubMed

    Babu, S; Shenolikar, I S

    1995-11-01

    Colour is a vital constituent of food which imparts distinct appearance to the food product. Artificial colouring becomes a technological necessity as foods tend to lose their natural shade during processing and storage. Most of the food colours tested in the conventional toxicity experiments showed toxic effects at a very high level of intake i.e., 1-5 per cent in the diet. However, such levels of intake are not normally encountered. Human studies indicated that food colours, (natural or synthetic) can induce wide range of allergic reactions only in sensitive or atopic individuals. Most of the foodborne diseases reported are due to the consumption of non-permitted textile colours or abuse of colours. The Government is pressurised periodically to place a total ban on the use of food colours due to their possible ill effects. It should be realised that surveillance should go hand in hand with legal actions.

  16. Generation of large field SEM image by panorama composition technology for nano-order measurement

    NASA Astrophysics Data System (ADS)

    Miyamoto, Atsushi; Hojyo, Yutaka

    2016-02-01

    Semiconductor manufacturing has a pressing need for a method to accurately evaluate the global shape deformation of a photomask pattern. We thus propose a novel composition technique for a large field panorama image of scanning electron microscopy (SEM). The proposed method optimises the arrangement of segmented imaging regions (SIRs), which are components of a panorama image, on the basis of the design data of the photomask pattern layout. The quantity of the line pattern segment, which is a clue to the connection in an overlapping region between adjoining SIRs and the connectability of any two SIRs, is evaluated. As a result of the optimisation, it is guaranteed that all SIR images can be connected theoretically. For 30 evaluation points, the maximum connection error of the SIR images was 1.5 nm in a simulation using pseudo-SEM images. The maximum total measurement error, which includes the connection error and CD measurement error from the panorama image, is estimated at 2.5 nm. This error was equivalent to about 1.4% of the photomask line width (target: 3%). The experiments using real SEM images demonstrate the effectiveness of the proposed method. It was visually confirmed that a large field, high-resolution and seamless panorama image can be generated.

  17. Colour agnosia impairs the recognition of natural but not of non-natural scenes.

    PubMed

    Nijboer, Tanja C W; Van Der Smagt, Maarten J; Van Zandvoort, Martine J E; De Haan, Edward H F

    2007-03-01

    Scene recognition can be enhanced by appropriate colour information, yet the level of visual processing at which colour exerts its effects is still unclear. It has been suggested that colour supports low-level sensory processing, while others have claimed that colour information aids semantic categorization and recognition of objects and scenes. We investigated the effect of colour on scene recognition in a case of colour agnosia, M.A.H. In a scene identification task, participants had to name images of natural or non-natural scenes in six different formats. Irrespective of scene format, M.A.H. was much slower on the natural than on the non-natural scenes. As expected, neither M.A.H. nor control participants showed any difference in performance for the non-natural scenes. However, for the natural scenes, appropriate colour facilitated scene recognition in control participants (i.e., shorter reaction times), whereas M.A.H.'s performance did not differ across formats. Our data thus support the hypothesis that the effect of colour occurs at the level of learned associations.

  18. Compensating for colour artefacts in the design of technical kaleidoscopes

    NASA Astrophysics Data System (ADS)

    Němcová, Šárka; Havran, Vlastimil; Čáp, Jiří; Hošek, Jan; Bittner, Jiří

    2016-04-01

    In computer graphics and related fields, bidirectional texture function (BTF) is used for realistic and predictive rendering. BTF allows for the capture of fine appearance effects such as self-shadowing, inter-reflection and subsurface scattering needed for true realism when used in rendering algorithms. The goal of current research is to get a surface representation indistinguishable from the real world. We developed, produced and tested a portable instrument for BTF acquisition based on kaleidoscopic imaging. Here we discuss the colour issues we experienced after the initial tests. We show that the same colour balance cannot be applied to the whole picture as the spectral response of the instrument varies with the position in the image. All optical elements were inspected for their contributions to the spectral behaviour of the instrument. The off-the-shelf parts were either measured or the manufacturer's data were considered. The custom made mirrors' spectral reflectivity was simulated. The mathematical model of the instrument was made. We found a way how to implement all these contributions to the image processing pipeline. In this way, a correct white balance for each individual pixel in the image is found and applied, allowing for a more faithful colour representation. Also proposed is an optimized dielectric protective layer for the kaleidoscope's mirrors.

  19. Colour stability of three esthetic laminate materials against to different staining agents.

    PubMed

    Belli, S; Tanriverdi, F F; Belli, E

    1997-09-01

    The purpose of the present study was to evaluate the colour stability of three laminate veneer materials against to tea, coffee and cigarette smoke. 72 discs prepared by using two different type composite materials and a dental porcelain were divided into groups and immersed into distilled water, tea, Turkish coffee solutions. The last group was exposed to cigarette smoke. Colour differences were measured by colorimeter at the beginning and then in the period of 1 day, 1 week and 1 month respectively. As a result, it was found that cigarette smoke was the most staining agent, porcelain material was the most colour stable material, and indirect composite material was more colour stable than the direct one. PMID:9569793

  20. Characterization of impact damage in metallic/nonmetallic composites using x-ray computed tomography imaging

    NASA Astrophysics Data System (ADS)

    Green, William H.; Wells, Joseph M.

    1999-12-01

    Characterizing internal impact damage in composites can be difficult, especially in structurally complex composites or those consisting of many materials. Many methods for nondestructive inspection/nondestructive testing (NDI/NDT) of materials have been known and in use for many years, including x-ray film, real-time, and digital radiographic techniques, and ultrasonic techniques. However, these techniques are generally not capable of three-dimensional (3D) mapping of complex damage patterns, which is necessary to visualize and understand damage cracking modes. Conventional x-ray radiography suffers from the loss of 3D information. Structural complexity and signal dispersion in materials with many interfaces significantly effect ultrasonic inspection techniques. This makes inspection scan interpretation difficult, especially in composites containing a number of different materials (i.e., polymer, ceramic, and metallic). X-ray computed tomography (CT) is broadly applicable to any material or test object through which a beam of penetrating radiation may be passed and detected, including metals, plastics, ceramics, metallic/nonmetallic composites, and assemblies. The principal advantage of CT is that it provides densitometric (that is, radiological density and geometry) images of thin cross sections through an object. Because of the absence of structural superposition, images are much easier to interpret than conventional radiological images. The user can quickly learn to read CT data because images correspond more closely to the way the human mind visualizes 3D structures than projection radiology (that is, film radiography, real-time radiography (RTR), and digital radiography (DR)). Any number of CT images, or slices, from scanning an object can be volumetrically reconstructed to produce a 3D attenuation map of the object. The 3D attenuation data can be rendered using multiplanar or 3D solid visualization. In multiplanar visualization there are four planes of view

  1. Defect imaging with elastic waves in inhomogeneous-anisotropic materials with composite geometries.

    PubMed

    Shlivinski, A; Langenberg, K J

    2007-03-01

    Imaging of defects in composite structures plays an important role in non-destructive testing (NDT) with elastic waves, i.e., ultrasound. Traditionally the imaging of such defects is performed using the synthetic aperture focusing technique (SAFT) algorithm assuming homogeneous isotropic materials. However, if parts of the structure are inhomogeneous and/or anisotropic, this algorithm fail to produce correct results that are needed in order to asses the lifetime of the part under test. Here we present a modification of this algorithm which enables a correct imaging of defects in inhomogeneous and/or anisotropic composite structures, whence it is termed InASAFT. The InASAFT is based on the exact modelling of the structure in order to account for the true nature of the elastic wave propagation using travel time ray tracing techniques. The algorithm is validated upon several numerical and real life examples yielding satisfactory results for imaging of cracks. The modified algorithm suffers, though, from the same difficulties encountered in the SAFT algorithm, namely "ghost" images and eventual lack of clear focused images. However, these artifacts can be identified using a forward wave propagation analysis of the structure.

  2. Intervertebral disc magnetic resonance image: correlation with gross morphology and biochemical composition

    PubMed Central

    Bishop, Paul B

    1993-01-01

    The magnetic resonance image, gross morphology, and biochemical composition of the intervertebral disc nucleus pulposus (NP), anulus fibrosus (AF) and cartilaginous endplates (CEP) from two groups of three human lumbar spines were compared. Group I consisted of all healthy discs from young donors (Grade I) and group II was comprised of discs that had undergone degeneration and age-related changes (average Grade 4). The gross morphological changes in the individual disc tissues associated with ageing/degeneration were consistent with specific changes in the characteristics of the magnetic resonance image. In particular, the mid-nuclear band of decreased magnetic resonance signal intensity seen in Grade 4 discs was associated with the appearance of clefts and fissures as well as a region of mucinous infiltration. The results of the biochemical analysis suggest that the changes in signal intensity are not due merely to changes in water content, but are also associated with changes in proteoglycan content. The changes associated with ageing/degeneration in the magnetic resonance image of the disc were related to a decrease in the proteoglycan content of the AF and NP. The water content of the NP also decreased. There was no clear association between the biochemical composition of the CEP and the magnetic resonance image. These results demonstrate that magnetic resonance imaging is an effective technique for evaluating subtle morphological changes in the intervertebral disc tissues and may be a sensitive indicator of the proteoglycan content of the AF and NP. ImagesFigure 1Figure 2

  3. Identification of the elastic stiffness of composites using the virtual fields method and digital image correlation

    NASA Astrophysics Data System (ADS)

    Jiang, Lebin; Guo, Baoqiao; Xie, Huimin

    2015-04-01

    This paper presents an effective methodology for characterizing the mechanical parameters of composites using digital image correlation combined with the virtual fields method. By using a three-point bending test configuration, this method can identify all mechanical parameters of the material with merely a single test. Successful results verified that this method is especially effective for characterizing composite materials. In this study, the method is applied to measure the orthotropic elastic parameters of fiber-reinforced polymer-matrix composites before and after the hygrothermal aging process. The results indicate that the hygrothermal aging environment significantly influences the mechanical property of a composite. The components of the parameters in the direction of the fiber bundle decreased significantly. From the accuracy analysis, we found that the actual measurement accuracy is sensitive to a shift of the horizontal edges and rotation of the vertical edges.

  4. Put on that colour, it fits your emotion: Colour appropriateness as a function of expressed emotion.

    PubMed

    Dael, Nele; Perseguers, Marie-Noëlle; Marchand, Cynthia; Antonietti, Jean-Philippe; Mohr, Christine

    2016-01-01

    People associate affective meaning with colour, and this may influence decisions about colours. Hue is traditionally considered the most salient descriptor of colour and colour-affect associations, although colour brightness and saturation seem to have particularly strong affective connotations. To test whether colour choices can be driven by emotion, we investigated whether and how colour hue, brightness, and saturation are systematically associated with bodily expressions of positive (joy) and negative (fear) emotions. Twenty-five non-colour-blind participants viewed videos of these expressions and selected for each video the most appropriate colour using colour sliders providing values for hue, brightness, and saturation. The overall colour choices were congruent with the expressed emotion--that is, participants selected brighter and more saturated colours for joy expressions than for fear expressions. Also, colours along the red-yellow spectrum were deemed more appropriate for joy expressions and cyan-bluish hues for fear expressions. The current study adds further support to the role of emotion in colour choices by (a) showing that emotional information is spontaneously used in an unconstrained choice setting, (b) extending to ecologically valid stimuli occurring in everyday encounters (dressed bodies), and PMID:26339950

  5. Put on that colour, it fits your emotion: Colour appropriateness as a function of expressed emotion.

    PubMed

    Dael, Nele; Perseguers, Marie-Noëlle; Marchand, Cynthia; Antonietti, Jean-Philippe; Mohr, Christine

    2016-01-01

    People associate affective meaning with colour, and this may influence decisions about colours. Hue is traditionally considered the most salient descriptor of colour and colour-affect associations, although colour brightness and saturation seem to have particularly strong affective connotations. To test whether colour choices can be driven by emotion, we investigated whether and how colour hue, brightness, and saturation are systematically associated with bodily expressions of positive (joy) and negative (fear) emotions. Twenty-five non-colour-blind participants viewed videos of these expressions and selected for each video the most appropriate colour using colour sliders providing values for hue, brightness, and saturation. The overall colour choices were congruent with the expressed emotion--that is, participants selected brighter and more saturated colours for joy expressions than for fear expressions. Also, colours along the red-yellow spectrum were deemed more appropriate for joy expressions and cyan-bluish hues for fear expressions. The current study adds further support to the role of emotion in colour choices by (a) showing that emotional information is spontaneously used in an unconstrained choice setting, (b) extending to ecologically valid stimuli occurring in everyday encounters (dressed bodies), and

  6. True Color Images of the Earth created with the Geostationary Satellite Instrument MSG SEVIRI

    NASA Astrophysics Data System (ADS)

    Reuter, Maximilian

    2013-04-01

    One of the most famous pictures ever taken was by the crew of Apollo 17 in 1972, showing our Earth from a distance of about 45000km. This picture was named 'Blue Marble' and it reminds us of the beauty and uniqueness of our home planet. With geostationary satellites, such views of the Earth are possible without the need to have a photographer in space. However, up to the present, the production of such Blue Marble type images from geostationary satellite data has been impaired by the lack of channels in the visible spectral region. A method for the generation of full disk MSG (METEOSAT Second Generation) SEVIRI (Scanning-Enhanced Visible and Infrared Imager) true colour composite images will be presented. The algorithm mainly uses the SEVIRI channels VIS006 (0.6μm), NIR008 (0.8μm) and NIR016 (1.6μm). The lack of information in the blue and green parts of the visible spectrum is compensated by using data from NASA's (National Aeronautics and Space Administration's) Blue Marble next generation (BMNG) project to fill a look-up table (LUT) transforming RGB (red/green/blue) false colour composite images of VIS006/NIR008/NIR016 into true colour images. Tabulated radiative transfer calculations of a pure Rayleigh atmosphere are used to add an impression of Rayleigh scattering towards the sunlit horizon. The resulting images satisfy naive expectations: clouds are white or transparent, vegetated surfaces are greenish, deserts are sandy-coloured, the ocean is dark blue to black and a narrow halo due to Rayleigh scattering is visible at the sunlit horizon. Therefore, such images are easily interpretable also for inexperienced users not familiar with the characteristics of typical MSG false colour composite images. The images can be used for scientific applications to illustrate specific meteorological conditions or for non-scientific purposes, for example, for raising awareness in the public of the Earth's worthiness of protection.

  7. Brilliant Star in a Colourful Neighbourhood

    NASA Astrophysics Data System (ADS)

    2010-07-01

    A spectacular new image from ESO's Wide Field Imager at the La Silla Observatory in Chile shows the brilliant and unusual star WR 22 and its colourful surroundings. WR 22 is a very hot and bright star that is shedding its atmosphere into space at a rate many millions of times faster than the Sun. It lies in the outer part of the dramatic Carina Nebula from which it formed. Very massive stars live fast and die young. Some of these stellar beacons have such intense radiation passing through their thick atmospheres late in their lives that they shed material into space many millions of times more quickly than relatively sedate stars such as the Sun. These rare, very hot and massive objects are known as Wolf-Rayet stars [1], after the two French astronomers who first identified them in the mid-nineteenth century, and one of the most massive ones yet measured is known as WR 22. It appears at the centre of this picture, which was created from images taken through red, green and blue filters with the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile. WR 22 is a member of a double star system and has been measured to have a mass at least 70 times that of the Sun. WR 22 lies in the southern constellation of Carina, the keel of Jason's ship Argo in Greek mythology. Although the star lies over 5000 light-years from the Earth it is so bright that it can just be faintly seen with the unaided eye under good conditions. WR 22 is one of many exceptionally brilliant stars associated with the beautiful Carina Nebula (also known as NGC 3372) and the outer part of this huge region of star formation in the southern Milky Way forms the colourful backdrop to this image. The subtle colours of the rich background tapestry are a result of the interactions between the intense ultraviolet radiation coming from hot massive stars, including WR 22, and the vast gas clouds, mostly hydrogen, from which they formed. The central part of this enormous complex

  8. An aerial composite imaging method with multiple upright cameras based on axis-shift theory

    NASA Astrophysics Data System (ADS)

    Fang, Junyong; Liu, Xue; Xue, Yongqi; Tong, Qingxi

    2010-11-01

    Several composite camera systems were made for wide coverage by using 3 or 4 oblique cameras. A virtual projecting center and image was used for geometrical correction and mosaic with different projecting angles and different spatial resolutions caused by oblique cameras. An imaging method based axis-shift theory is proposed to acquire wide coverage images by several upright cameras. Four upright camera lenses have the same wide angle of view. The optic axis of lens is not on the center of CCD, and each CCD in each camera covers only one part of the whole focus plane. Oblique deformation caused by oblique camera would be avoided by this axis-shift imaging method. The principle and parameters are given and discussed. A prototype camera system is constructed by common DLSR (digital single lens reflex) cameras. The angle of view could exceed 80 degrees along the flight direction when the focal length is 24mm, and the ratio of base line to height could exceed 0.7 when longitudinal overlap is 60%. Some original and mosaic images captured by this prototype system in some ground and airborne experiments are given at last. Experimental results of image test show that the upright imaging method can effectively avoid the oblique deformation and meet the geometrical precision of image mosaic.

  9. Colorimetry and prime colours--a theorem.

    PubMed

    Hornaes, Hans Petter; Wold, Jan Henrik; Farup, Ivar

    2005-08-01

    Human colour vision is the result of a complex process involving topics ranging from physics of light to perception. Whereas the diversity of light entering the eye in principle span an infinite-dimensional vector space in terms of the spectral power distributions, the space of human colour perceptions is three dimensional. One important consequence of this is that a variety of colours can be visually matched by a mixture of only three adequately chosen reference lights. It has been observed that there exists one particular set of monochromatic reference lights that, according to a certain definition, is optimal for producing colour matches. These reference lights are commonly denoted prime colours. In the present paper, we intend to rigorously show that the existence of prime colours is not particular to the human visual system as sometimes stated, but rather an algebraic consequence of the manner in which a kind of colorimetric functions called colour-matching functions are defined and transformed. The solution is based on maximisation of a determinant determining the gamut size of the colour space spanned by the prime colours. Cramer's rule for solving a set of linear equations is an essential part of the proof. By means of examples, it is shown that mathematically the optimal set of reference lights is not unique in general, and that the existence of a maximum determinant is not a necessary condition for the existence of prime colours.

  10. The AMBEGUJAS phenomenon and colour constancy.

    PubMed

    Bergström, Sten Sture

    2004-01-01

    The AMBEGUJAS phenomenon is a reversible flat figure that is spontaneously shifting between two apparent 3-D shapes-'tile' and 'roof'. 2-D perceptions have very rarely been reported. Tied to the shifts between the tile and roof shapes are remarkable changes of perceived colour. In our example, the tile appears to have orange (top half) and blue-green (bottom half) surface colours in white light. The roof appears grey but in an orange illumination and with a blue-green shadow. This phenomenon appears whether a grey display is presented in two coloured illuminations, or a chromatic display with two surface colours (orange and blue-green) is presented in white light. In the coloured illuminations the tile is an example of non-constancy, since its colours are non-veridical colour perceptions. The centre stripe of the display appears to have the same orange and blue-green colours as the lateral stripes but in a shadow. This seems like a colour constancy in a non-constancy situation. An alternative to the classical definition of colour constancy is discussed.

  11. Measurement and prediction of pork colour.

    PubMed

    Van Oeckel, M J; Warnants, N; Boucqué, C V

    1999-08-01

    The extent to which instrumental colour determinations by FOPu (light scattering), Göfo (reflectance) and Labscan II (CIE L*, CIE a* and CIE b*, hue and chroma) are related to the Japanese colour grades was studied. Additionally, four on-line methods: pH1, FOP1, PQM1 (conductivity) and DDLT (Double Density Light Transmission, analogous to Capteur Gras/Maigre), were evaluated for their ability to predict subjectively and objectively colour. One hundred and twenty samples of m. longissimus thoracis et lumborum, from animals of different genotypes, were analysed. Of the instrumental colour determinations, CIE L* (r=-0.82), FOPu (r=-0.70) and Göfo (r=0.70) were best correlated with the Japanese colour scores. The Japanese colour grades could be predicted by the on-line instruments, pH1, FOP1, PQM1 and DDLT, with determination coefficients between 15 and 28%. Ultimate meat colour, determined by Japanese colour standards, FOPu, Göfo and CIE L*, was better predicted by DDLT than by the classic on-line instruments: FOP1, pH1 and PQM1, although the standard error of the estimate was similar for all instruments. This means that DDLT, although originally designed for estimating lean meat percentage, can additionally give information about meat quality, in particular colour. However, it must be stressed that the colour estimate by DDLT refers to a population of animals, rather than to individual pigs, because of the number of erroneously assigned samples.

  12. Opening up a Colourful Cosmic Jewel Box

    NASA Astrophysics Data System (ADS)

    2009-10-01

    The combination of images taken by three exceptional telescopes, the ESO Very Large Telescope on Cerro Paranal , the MPG/ESO 2.2-metre telescope at ESO's La Silla observatory and the NASA/ESA Hubble Space Telescope, has allowed the stunning Jewel Box star cluster to be seen in a whole new light. Star clusters are among the most visually alluring and astrophysically fascinating objects in the sky. One of the most spectacular nestles deep in the southern skies near the Southern Cross in the constellation of Crux. The Kappa Crucis Cluster, also known as NGC 4755 or simply the "Jewel Box" is just bright enough to be seen with the unaided eye. It was given its nickname by the English astronomer John Herschel in the 1830s because the striking colour contrasts of its pale blue and orange stars seen through a telescope reminded Herschel of a piece of exotic jewellery. Open clusters [1] such as NGC 4755 typically contain anything from a few to thousands of stars that are loosely bound together by gravity. Because the stars all formed together from the same cloud of gas and dust their ages and chemical makeup are similar, which makes them ideal laboratories for studying how stars evolve. The position of the cluster amongst the rich star fields and dust clouds of the southern Milky Way is shown in the very wide field view generated from the Digitized Sky Survey 2 data. This image also includes one of the stars of the Southern Cross as well as part of the huge dark cloud of the Coal Sack [2]. A new image taken with the Wide Field Imager (WFI) on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile shows the cluster and its rich surroundings in all their multicoloured glory. The large field of view of the WFI shows a vast number of stars. Many are located behind the dusty clouds of the Milky Way and therefore appear red [3]. The FORS1 instrument on the ESO Very Large Telescope (VLT) allows a much closer look at the cluster itself. The telescope's huge mirror

  13. A time reversal focusing based impact imaging method and its evaluation on complex composite structures

    NASA Astrophysics Data System (ADS)

    Qiu, Lei; Yuan, Shenfang; Zhang, Xiaoyue; Wang, Yu

    2011-10-01

    The growing use of composite structures in aerospace structures has attracted much interest in structural health monitoring (SHM) for the localization of impact positions due to their poor impact resistance properties. The propagation mechanism and the frequency dispersion features of signals on complex composite structures are more complicated than those on simple composite plates. In this paper, a time reversal focusing based impact imaging method for impact localization of complex composite structures is proposed. A complex Shannon wavelet transform is adopted to extract frequency narrow-band signals of impact response signals of a PZT sensors array at a special time-frequency scale and to measure the phase velocity of the signals. The frequency narrow-band signals are synthesized using software, depending on the time reversal focusing principle, to generate an impact image to estimate the impact position. A demonstration system is built on a composite panel with many bolt holes and stiffeners on an aircraft wing box to validate this method. The validating results show that the method can estimate the position of impact efficiently.

  14. Advanced imaging techniques for assessment of structure, composition and function in biofilm systems.

    PubMed

    Neu, Thomas R; Manz, Bertram; Volke, Frank; Dynes, James J; Hitchcock, Adam P; Lawrence, John R

    2010-04-01

    Scientific imaging represents an important and accepted research tool for the analysis and understanding of complex natural systems. Apart from traditional microscopic techniques such as light and electron microscopy, new advanced techniques have been established including laser scanning microscopy (LSM), magnetic resonance imaging (MRI) and scanning transmission X-ray microscopy (STXM). These new techniques allow in situ analysis of the structure, composition, processes and dynamics of microbial communities. The three techniques open up quantitative analytical imaging possibilities that were, until a few years ago, impossible. The microscopic techniques represent powerful tools for examination of mixed environmental microbial communities usually encountered in the form of aggregates and films. As a consequence, LSM, MRI and STXM are being used in order to study complex microbial biofilm systems. This mini review provides a short outline of the more recent applications with the intention to stimulate new research and imaging approaches in microbiology.

  15. Color composite C-band and L-band image of Kilauea volcanoe on Hawaii

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This color composite C-band and L-band image of the Kilauea volcano on the Big Island of Hawaii was acuired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperature Radar (SIR-C/X-SAR) flying on the Space Shuttle Endeavour. The city of Hilo can be seen at the top. The image shows the different types of lava flows around the crater Pu'u O'o. Ash deposits which erupted in 1790 from the summit of Kilauea volcano show up as dark in this image, and fine details associated with lava flows which erupted in 1919 and 1974 can be seen to the south of the summit in an area called the Ka'u Desert. Other historic lava flows can also be seen. Highway 11 is the linear feature running from Hilo to the Kilauea volcano. The Jet Propulsion Laboratory alternative photo number is P-43918.

  16. True and false memory for colour names versus actual colours: support for the visual distinctiveness heuristic in memory for colour information.

    PubMed

    Eslick, Andrea N; Kostic, Bogdan; Cleary, Anne M

    2010-06-01

    In a colour variation of the Deese-Roediger-McDermott (DRM) false memory paradigm, participants studied lists of words critically related to a nonstudied colour name (e.g., "blood, cherry, scarlet, rouge ... "); they later showed false memory for the critical colour name (e.g., "red"). Two additional experiments suggest that participants generate colour imagery in response to such colour-related DRM lists. First, participants claim to experience colour imagery more often following colour-related than standard non-colour-related DRM lists; they also rate their colour imagery as more vivid following colour-related lists. Second, participants exhibit facilitative priming for critical colours in a dot selection task that follows words in the colour-related DRM list, suggesting that colour-related DRM lists prime participants for the actual critical colours themselves. Despite these findings, false memory for critical colour names does not extend to the actual colours themselves (font colours). Rather than leading to source confusion about which colours were self-generated and which were studied, presenting the study lists in varied font colours actually worked to reduce false memory overall. Results are interpreted within the framework of the visual distinctiveness hypothesis.

  17. Zebrafish stripes as a model for vertebrate colour pattern formation.

    PubMed

    Singh, Ajeet Pratap; Nüsslein-Volhard, Christiane

    2015-01-19

    Colour patterns are prominent features of many animals and have important functions in communication, such as camouflage, kin recognition and mate choice. As targets for natural as well as sexual selection, they are of high evolutionary significance. The molecular mechanisms underlying colour pattern formation in vertebrates are not well understood. Progress in transgenic tools, in vivo imaging and the availability of a large collection of mutants make the zebrafish (Danio rerio) an attractive model to study vertebrate colouration. Zebrafish display golden and blue horizontal stripes that form during metamorphosis as mosaics of yellow xanthophores, silvery or blue iridophores and black melanophores in the hypodermis. Lineage tracing revealed the origin of the adult pigment cells and their individual cellular behaviours during the formation of the striped pattern. Mutant analysis indicated that interactions between all three pigment cell types are required for the formation of the pattern, and a number of cell surface molecules and signalling systems have been identified as mediators of these interactions. The understanding of the mechanisms that underlie colour pattern formation is an important step towards deciphering the genetic basis of variation in evolution. PMID:25602311

  18. A cross-cultural study of colour grouping: evidence for weak linguistic relativity.

    PubMed

    Davies, I R; Corbett, G G

    1997-08-01

    We report a cross-cultural study of colour grouping carried out as a test of the Sapir-Whorf hypothesis (linguistic relativity theory). Speakers of English, Russian and Setswana-languages that differ in their number of basic colour terms, and in how the blue-green region is categorized--were compared on a colour sorting task. Informants sorted a representative set of 65 colours into groups so that members of the groups looked similar to each other, with no restriction on the number of groups formed. If linguistic relativity theory is true, then there should be reliable differences between the three samples in the composition of the groups they formed associated with the differing positions of colour category boundaries in the languages. The most striking feature of the results, inconsistent with linguistic relativity theory, was the similarity amongst the patterns of choice of the three samples. However, there were also significant differences amongst the samples. Setswana speakers (who have a single basic term for BLUE or GREEN) were more likely to group BLUE colours with GREEN colours than either English or Russian speakers. But Russian speakers (who have two basic colour terms for BLUE) were no more likely than English speakers to group light and dark BLUE separately. In addition there were general structural differences in grouping among the samples: they differed in the level of consensus in grouping, the number of groups formed and in the distribution of the number of colours placed in a group. These structural differences may reflect differences in the availability and salience of the colour categories across the languages. Our data support perceptual universalism modulated by weaker linguistic effects. PMID:9290238

  19. A cross-cultural study of colour grouping: evidence for weak linguistic relativity.

    PubMed

    Davies, I R; Corbett, G G

    1997-08-01

    We report a cross-cultural study of colour grouping carried out as a test of the Sapir-Whorf hypothesis (linguistic relativity theory). Speakers of English, Russian and Setswana-languages that differ in their number of basic colour terms, and in how the blue-green region is categorized--were compared on a colour sorting task. Informants sorted a representative set of 65 colours into groups so that members of the groups looked similar to each other, with no restriction on the number of groups formed. If linguistic relativity theory is true, then there should be reliable differences between the three samples in the composition of the groups they formed associated with the differing positions of colour category boundaries in the languages. The most striking feature of the results, inconsistent with linguistic relativity theory, was the similarity amongst the patterns of choice of the three samples. However, there were also significant differences amongst the samples. Setswana speakers (who have a single basic term for BLUE or GREEN) were more likely to group BLUE colours with GREEN colours than either English or Russian speakers. But Russian speakers (who have two basic colour terms for BLUE) were no more likely than English speakers to group light and dark BLUE separately. In addition there were general structural differences in grouping among the samples: they differed in the level of consensus in grouping, the number of groups formed and in the distribution of the number of colours placed in a group. These structural differences may reflect differences in the availability and salience of the colour categories across the languages. Our data support perceptual universalism modulated by weaker linguistic effects.

  20. Capability of Thermographic Imaging Defined for Detection in High-Temperature Composite Materials

    NASA Technical Reports Server (NTRS)

    Roth, Don J.

    1997-01-01

    Significant effort and resources are being expended to develop ceramic matrix (CMC), metal matrix (MMC), and polymer matrix (PMC) composites for high-temperature engine components and other parts in advanced aircraft. The objective of this NASA Lewis Research Center study was to evaluate the ability of a thermographic imaging technique for detecting artificially created defects (flat-bottom holes) of various diameters and depths in four composite systems (two CMC's, one MMC, and one PMC) of interest as high-temperature structural materials.

  1. Fruit over sunbed: carotenoid skin colouration is found more attractive than melanin colouration.

    PubMed

    Lefevre, Carmen E; Perrett, David I

    2015-01-01

    Skin colouration appears to play a pivotal part in facial attractiveness. Skin yellowness contributes to an attractive appearance and is influenced both by dietary carotenoids and by melanin. While both increased carotenoid colouration and increased melanin colouration enhance apparent health in Caucasian faces by increasing skin yellowness, it remains unclear, firstly, whether both pigments contribute to attractiveness judgements, secondly, whether one pigment is clearly preferred over the other, and thirdly, whether these effects depend on the sex of the face. Here, in three studies, we examine these questions using controlled facial stimuli transformed to be either high or low in (a) carotenoid colouration, or (b) melanin colouration. We show, firstly, that both increased carotenoid colouration and increased melanin colouration are found attractive compared to lower levels of these pigments. Secondly, we show that carotenoid colouration is consistently preferred over melanin colouration when levels of colouration are matched. In addition, we find an effect of the sex of stimuli with stronger preferences for carotenoids over melanin in female compared to male faces, irrespective of the sex of the observer. These results are interpreted as reflecting preferences for sex-typical skin colouration: men have darker skin than women and high melanization in male faces may further enhance this masculine trait, thus carotenoid colouration is not less desirable, but melanin colouration is relatively more desirable in males compared to females. Taken together, our findings provide further support for a carotenoid-linked health-signalling system that is highly important in mate choice.

  2. Volume and tissue composition preserving deformation of breast CT images to simulate breast compression in mammographic imaging

    NASA Astrophysics Data System (ADS)

    Han, Tao; Chen, Lingyun; Lai, Chao-Jen; Liu, Xinming; Shen, Youtao; Zhong, Yuncheng; Ge, Shuaiping; Yi, Ying; Wang, Tianpeng; Shaw, Chris C.

    2009-02-01

    Images of mastectomy breast specimens have been acquired with a bench top experimental Cone beam CT (CBCT) system. The resulting images have been segmented to model an uncompressed breast for simulation of various CBCT techniques. To further simulate conventional or tomosynthesis mammographic imaging for comparison with the CBCT technique, a deformation technique was developed to convert the CT data for an uncompressed breast to a compressed breast without altering the breast volume or regional breast density. With this technique, 3D breast deformation is separated into two 2D deformations in coronal and axial views. To preserve the total breast volume and regional tissue composition, each 2D deformation step was achieved by altering the square pixels into rectangular ones with the pixel areas unchanged and resampling with the original square pixels using bilinear interpolation. The compression was modeled by first stretching the breast in the superior-inferior direction in the coronal view. The image data were first deformed by distorting the voxels with a uniform distortion ratio. These deformed data were then deformed again using distortion ratios varying with the breast thickness and re-sampled. The deformation procedures were applied in the axial view to stretch the breast in the chest wall to nipple direction while shrinking it in the mediolateral to lateral direction re-sampled and converted into data for uniform cubic voxels. Threshold segmentation was applied to the final deformed image data to obtain the 3D compressed breast model. Our results show that the original segmented CBCT image data were successfully converted into those for a compressed breast with the same volume and regional density preserved. Using this compressed breast model, conventional and tomosynthesis mammograms were simulated for comparison with CBCT.

  3. Characterization of propagation and scattering via wavefield imaging for improved in situ imaging of damage in composites

    NASA Astrophysics Data System (ADS)

    Williams, Westin B.; Michaels, Jennifer E.; Michaels, Thomas E.

    2016-04-01

    Detection, localization, and characterization of impact damage in composites using in situ transducers are important objectives for the aerospace industry to both reduce maintenance costs and prevent failures. A network of piezoelectric transducers spatially distributed over an area of interest is one practical configuration for utilizing guided waves to accomplish these objectives. Detecting and localizing barely visible impact damage with such a sparse array has been demonstrated in prior work, and improvements in localization were demonstrated by incorporating fairly crude estimates of scattering patterns in the imaging algorithms. Here we obtain more estimates of scattering patterns from a simulated defect by employing baseline subtraction of wavefield data recorded in a circle centered at the scatterer. Scattering patterns are estimated from the wavefield residual signals before and after simulated damage is introduced and the estimated scattering patterns are then incorporated into sparse array imaging via the minimum variance imaging method. Images created with different scattering patterns are compared and the efficacy of the methodology is assessed.

  4. Colour Consideration for Waiting areas in hospitals

    NASA Astrophysics Data System (ADS)

    Zraati, Parisa

    2012-08-01

    Colour is one the most important factors in the nature that can have some affects on human behaviour. Many years ago, it was proven that using colour in public place can have some affect on the users. Depend of the darkness and lightness; it can be vary from positive to negative. The research will mainly focus on the colour and psychological influences and physical factors. The statement of problem in this research is what is impact of colour usually applied to waiting area? The overall aim of the study is to explore the visual environment of hospitals and to manage the colour psychological effect of the hospital users in the waiting area by creating a comfortable, pleasant and cozy environment for users while spend their time in waiting areas. The analysisconcentrate on satisfaction and their interesting regarding applied colour in two private hospital waiting area in Malaysia.

  5. Testosterone-Induced Expression of Male Colour Morphs in Females of the Polymorphic Tawny Dragon Lizard, Ctenophorus decresii.

    PubMed

    Rankin, Katrina; Stuart-Fox, Devi

    2015-01-01

    Many colour polymorphisms are present only in one sex, usually males, but proximate mechanisms controlling the expression of sex-limited colour polymorphisms have received little attention. Here, we test the hypothesis that artificial elevation of testosterone in females of the colour polymorphic tawny dragon lizard, Ctenophorus decresii, can induce them to express the same colour morphs, in similar frequencies, to those found in males. Male C. decresii, express four discrete throat colour morphs (orange, yellow, grey and an orange central patch surrounded by yellow). We used silastic implants to experimentally elevate testosterone levels in mature females to induce colour expression. Testosterone elevation resulted in a substantial increase in the proportion and intensity of orange but not yellow colouration, which was present in a subset of females prior to treatment. Consequently, females exhibited the same set of colour morphs as males, and we confirmed that these morphs are objectively classifiable, by using digital image analyses and spectral reflectance measurements, and occur in similar frequencies as in males. These results indicate that the influence of testosterone differs for different colours, suggesting that their expression may be governed by different proximate hormonal mechanisms. Thus, caution must be exercised when using artificial testosterone manipulation to induce female expression of sex-limited colour polymorphisms. Nevertheless, the ability to express sex-limited colours (in this case orange) to reveal the same, objectively classifiable morphs in similar frequencies to males suggests autosomal rather than sex-linked inheritance, and can facilitate further research on the genetic basis of colour polymorphism, including estimating heritability and selection on colour morphs from pedigree data. PMID:26485705

  6. Testosterone-Induced Expression of Male Colour Morphs in Females of the Polymorphic Tawny Dragon Lizard, Ctenophorus decresii.

    PubMed

    Rankin, Katrina; Stuart-Fox, Devi

    2015-01-01

    Many colour polymorphisms are present only in one sex, usually males, but proximate mechanisms controlling the expression of sex-limited colour polymorphisms have received little attention. Here, we test the hypothesis that artificial elevation of testosterone in females of the colour polymorphic tawny dragon lizard, Ctenophorus decresii, can induce them to express the same colour morphs, in similar frequencies, to those found in males. Male C. decresii, express four discrete throat colour morphs (orange, yellow, grey and an orange central patch surrounded by yellow). We used silastic implants to experimentally elevate testosterone levels in mature females to induce colour expression. Testosterone elevation resulted in a substantial increase in the proportion and intensity of orange but not yellow colouration, which was present in a subset of females prior to treatment. Consequently, females exhibited the same set of colour morphs as males, and we confirmed that these morphs are objectively classifiable, by using digital image analyses and spectral reflectance measurements, and occur in similar frequencies as in males. These results indicate that the influence of testosterone differs for different colours, suggesting that their expression may be governed by different proximate hormonal mechanisms. Thus, caution must be exercised when using artificial testosterone manipulation to induce female expression of sex-limited colour polymorphisms. Nevertheless, the ability to express sex-limited colours (in this case orange) to reveal the same, objectively classifiable morphs in similar frequencies to males suggests autosomal rather than sex-linked inheritance, and can facilitate further research on the genetic basis of colour polymorphism, including estimating heritability and selection on colour morphs from pedigree data.

  7. Testosterone-Induced Expression of Male Colour Morphs in Females of the Polymorphic Tawny Dragon Lizard, Ctenophorus decresii

    PubMed Central

    Rankin, Katrina; Stuart-Fox, Devi

    2015-01-01

    Many colour polymorphisms are present only in one sex, usually males, but proximate mechanisms controlling the expression of sex-limited colour polymorphisms have received little attention. Here, we test the hypothesis that artificial elevation of testosterone in females of the colour polymorphic tawny dragon lizard, Ctenophorus decresii, can induce them to express the same colour morphs, in similar frequencies, to those found in males. Male C. decresii, express four discrete throat colour morphs (orange, yellow, grey and an orange central patch surrounded by yellow). We used silastic implants to experimentally elevate testosterone levels in mature females to induce colour expression. Testosterone elevation resulted in a substantial increase in the proportion and intensity of orange but not yellow colouration, which was present in a subset of females prior to treatment. Consequently, females exhibited the same set of colour morphs as males, and we confirmed that these morphs are objectively classifiable, by using digital image analyses and spectral reflectance measurements, and occur in similar frequencies as in males. These results indicate that the influence of testosterone differs for different colours, suggesting that their expression may be governed by different proximate hormonal mechanisms. Thus, caution must be exercised when using artificial testosterone manipulation to induce female expression of sex-limited colour polymorphisms. Nevertheless, the ability to express sex-limited colours (in this case orange) to reveal the same, objectively classifiable morphs in similar frequencies to males suggests autosomal rather than sex-linked inheritance, and can facilitate further research on the genetic basis of colour polymorphism, including estimating heritability and selection on colour morphs from pedigree data. PMID:26485705

  8. Colour Vision Impairment in Young Alcohol Consumers.

    PubMed

    Brasil, Alódia; Castro, Antônio José O; Martins, Isabelle Christine V S; Lacerda, Eliza Maria C B; Souza, Givago S; Herculano, Anderson Manoel; Rosa, Alexandre Antônio M; Rodrigues, Anderson R; Silveira, Luiz Carlos L

    2015-01-01

    Alcohol consumption among young adults is widely accepted in modern society and may be the starting point for abusive use of alcohol at later stages of life. Chronic alcohol exposure can lead to visual function impairment. In the present study, we investigated the spatial luminance contrast sensitivity, colour arrangement ability, and colour discrimination thresholds on young adults that weekly consume alcoholic beverages without clinical concerns. Twenty-four young adults were evaluated by an ophthalmologist and performed three psychophysical tests to evaluate their vision functions. We estimated the spatial luminance contrast sensitivity function at 11 spatial frequencies ranging from 0.1 to 30 cycles/degree. No difference in contrast sensitivity was observed comparing alcohol consumers and control subjects. For the evaluation of colour vision, we used the Farnsworth-Munsell 100 hue test (FM 100 test) to test subject's ability to perform a colour arrangement task and the Mollon-Reffin test (MR test) to measure subject's colour discrimination thresholds. Alcohol consumers made more mistakes than controls in the FM100 test, and their mistakes were diffusely distributed in the FM colour space without any colour axis preference. Alcohol consumers also performed worse than controls in the MR test and had higher colour discrimination thresholds compared to controls around three different reference points of a perceptually homogeneous colour space, the CIE 1976 chromaticity diagram. There was no colour axis preference in the threshold elevation observed among alcoholic subjects. Young adult weekly alcohol consumers showed subclinical colour vision losses with preservation of spatial luminance contrast sensitivity. Adolescence and young adult age are periods of important neurological development and alcohol exposure during this period of life might be responsible for deficits in visual functions, especially colour vision that is very sensitive to neurotoxicants. PMID

  9. Colour Vision Impairment in Young Alcohol Consumers.

    PubMed

    Brasil, Alódia; Castro, Antônio José O; Martins, Isabelle Christine V S; Lacerda, Eliza Maria C B; Souza, Givago S; Herculano, Anderson Manoel; Rosa, Alexandre Antônio M; Rodrigues, Anderson R; Silveira, Luiz Carlos L

    2015-01-01

    Alcohol consumption among young adults is widely accepted in modern society and may be the starting point for abusive use of alcohol at later stages of life. Chronic alcohol exposure can lead to visual function impairment. In the present study, we investigated the spatial luminance contrast sensitivity, colour arrangement ability, and colour discrimination thresholds on young adults that weekly consume alcoholic beverages without clinical concerns. Twenty-four young adults were evaluated by an ophthalmologist and performed three psychophysical tests to evaluate their vision functions. We estimated the spatial luminance contrast sensitivity function at 11 spatial frequencies ranging from 0.1 to 30 cycles/degree. No difference in contrast sensitivity was observed comparing alcohol consumers and control subjects. For the evaluation of colour vision, we used the Farnsworth-Munsell 100 hue test (FM 100 test) to test subject's ability to perform a colour arrangement task and the Mollon-Reffin test (MR test) to measure subject's colour discrimination thresholds. Alcohol consumers made more mistakes than controls in the FM100 test, and their mistakes were diffusely distributed in the FM colour space without any colour axis preference. Alcohol consumers also performed worse than controls in the MR test and had higher colour discrimination thresholds compared to controls around three different reference points of a perceptually homogeneous colour space, the CIE 1976 chromaticity diagram. There was no colour axis preference in the threshold elevation observed among alcoholic subjects. Young adult weekly alcohol consumers showed subclinical colour vision losses with preservation of spatial luminance contrast sensitivity. Adolescence and young adult age are periods of important neurological development and alcohol exposure during this period of life might be responsible for deficits in visual functions, especially colour vision that is very sensitive to neurotoxicants.

  10. Colour vision deficiency and physics teaching

    NASA Astrophysics Data System (ADS)

    Maule, Louise; Featonby, David

    2016-05-01

    1 in 12 males suffer from some form of colour vision deficiency (CVD) which in the present colour dominated world of education presentation can be a severe disadvantage. Although aware of ‘colourblindness’ most teachers make little or no adjustment for these pupils for whom tasks may be more difficult. This article examines colour vision deficiency and looks at ways in which we can help the many students who have this problem.

  11. Colour Vision Impairment in Young Alcohol Consumers

    PubMed Central

    Brasil, Alódia; Castro, Antônio José O.; Martins, Isabelle Christine V. S.; Lacerda, Eliza Maria C. B.; Souza, Givago S.; Herculano, Anderson Manoel; Rosa, Alexandre Antônio M.; Rodrigues, Anderson R.; Silveira, Luiz Carlos L.

    2015-01-01

    Alcohol consumption among young adults is widely accepted in modern society and may be the starting point for abusive use of alcohol at later stages of life. Chronic alcohol exposure can lead to visual function impairment. In the present study, we investigated the spatial luminance contrast sensitivity, colour arrangement ability, and colour discrimination thresholds on young adults that weekly consume alcoholic beverages without clinical concerns. Twenty-four young adults were evaluated by an ophthalmologist and performed three psychophysical tests to evaluate their vision functions. We estimated the spatial luminance contrast sensitivity function at 11 spatial frequencies ranging from 0.1 to 30 cycles/degree. No difference in contrast sensitivity was observed comparing alcohol consumers and control subjects. For the evaluation of colour vision, we used the Farnsworth-Munsell 100 hue test (FM 100 test) to test subject’s ability to perform a colour arrangement task and the Mollon-Reffin test (MR test) to measure subject’s colour discrimination thresholds. Alcohol consumers made more mistakes than controls in the FM100 test, and their mistakes were diffusely distributed in the FM colour space without any colour axis preference. Alcohol consumers also performed worse than controls in the MR test and had higher colour discrimination thresholds compared to controls around three different reference points of a perceptually homogeneous colour space, the CIE 1976 chromaticity diagram. There was no colour axis preference in the threshold elevation observed among alcoholic subjects. Young adult weekly alcohol consumers showed subclinical colour vision losses with preservation of spatial luminance contrast sensitivity. Adolescence and young adult age are periods of important neurological development and alcohol exposure during this period of life might be responsible for deficits in visual functions, especially colour vision that is very sensitive to neurotoxicants. PMID

  12. BOREAS Level-4c AVHRR-LAC Ten-Day Composite Images: Surface Parameters

    NASA Technical Reports Server (NTRS)

    Cihlar, Josef; Chen, Jing; Huang, Fengting; Nickeson, Jaime; Newcomer, Jeffrey A.; Hall, Forrest G. (Editor)

    2000-01-01

    The BOReal Ecosystem-Atmosphere Study (BOREAS) Staff Science Satellite Data Acquisition Program focused on providing the research teams with the remotely sensed satellite data products they needed to compare and spatially extend point results. Manitoba Remote Sensing Center (MRSC) and BOREAS Information System (BORIS) personnel acquired, processed, and archived data from the Advanced Very High Resolution Radiometer (AVHRR) instruments on the NOAA-11 and -14 satellites. The AVHRR data were acquired by CCRS and were provided to BORIS for use by BOREAS researchers. These AVHRR level-4c data are gridded, 10-day composites of surface parameters produced from sets of single-day images. Temporally, the 10-day compositing periods begin 11-Apr-1994 and end 10-Sep-1994. Spatially, the data cover the entire BOREAS region. The data are stored in binary image format files. Note: Some of the data files on the BOREAS CD-ROMs have been compressed using the Gzip program.

  13. BOREAS Level-4b AVHRR-LAC Ten-Day Composite Images: At-sensor Radiance

    NASA Technical Reports Server (NTRS)

    Cihlar, Josef; Chen, Jing; Nickerson, Jaime; Newcomer, Jeffrey A.; Huang, Feng-Ting; Hall, Forrest G. (Editor)

    2000-01-01

    The BOReal Ecosystem-Atmosphere Study (BOREAS) Staff Science Satellite Data Acquisition Program focused on providing the research teams with the remotely sensed satellite data products they needed to compare and spatially extend point results. Manitoba Remote Sensing Center (MRSC) and BOREAS Information System (BORIS) personnel acquired, processed, and archived data from the Advanced Very High Resolution Radiometer (AVHRR) instruments on the National Oceanic and Atmospheric Administration (NOAA-11) and -14 satellites. The AVHRR data were acquired by CCRS and were provided to BORIS for use by BOREAS researchers. These AVHRR level-4b data are gridded, 10-day composites of at-sensor radiance values produced from sets of single-day images. Temporally, the 10- day compositing periods begin 11-Apr-1994 and end 10-Sep-1994. Spatially, the data cover the entire BOREAS region. The data are stored in binary image format files.

  14. Biological impedance cross evaluation and imaging from composite measurements of magnetic and electrical methods.

    PubMed

    Ran, Peng; Xiao, Xiaoming; He, Wei; Li, Zhangyong

    2015-01-01

    Because of the need for rapid detection and location of diseases in clinical applications, this work proposes a composite measurement of magnetic induction tomography (MIT) and electrical impedance tomography (EIT). This paper is composed of the following aspects: portable and integral hardware design, stable dual constant-current sources, the composite detection method, cross-plane data acquirement, 3-dimensional image reconstruction and so on. A qualitative evaluation of conductivity, resolution and relative position error were taken by combining the EIT and MIT methods via the experiment model. The sensitivities of both methods were analyzed to improve the imaging results. The reconstruction results reveal that the system is capable of obtaining better physiological measurements, which is very useful in clinical monitoring, quick medical diagnosing and preliminary screening of community health. PMID:26405936

  15. Evaluation of a rule-based compositing technique for Landsat-5 TM and Landsat-7 ETM+ images

    NASA Astrophysics Data System (ADS)

    Lück, W.; van Niekerk, A.

    2016-05-01

    Image compositing is a multi-objective optimization process. Its goal is to produce a seamless cloud and artefact-free artificial image. This is achieved by aggregating image observations and by replacing poor and cloudy data with good observations from imagery acquired within the timeframe of interest. This compositing process aims to minimise the visual artefacts which could result from different radiometric properties, caused by atmospheric conditions, phenologic patterns and land cover changes. It has the following requirements: (1) image compositing must be cloud free, which requires the detection of clouds and shadows, and (2) the image composite must be seamless, minimizing artefacts and visible across inter image seams. This study proposes a new rule-based compositing technique (RBC) that combines the strengths of several existing methods. A quantitative and qualitative evaluation is made of the RBC technique by comparing it to the maximum NDVI (MaxNDVI), minimum red (MinRed) and maximum ratio (MaxRatio) compositing techniques. A total of 174 Landsat TM and ETM+ images, covering three study sites and three different timeframes for each site, are used in the evaluation. A new set of quantitative/qualitative evaluation techniques for compositing quality measurement was developed and showed that the RBC technique outperformed all other techniques, with MaxRatio, MaxNDVI, and MinRed techniques in order of performance from best to worst.

  16. Colour thresholds in a coral reef fish

    PubMed Central

    Vorobyev, M.; Marshall, N. J.

    2016-01-01

    Coral reef fishes are among the most colourful animals in the world. Given the diversity of lifestyles and habitats on the reef, it is probable that in many instances coloration is a compromise between crypsis and communication. However, human observation of this coloration is biased by our primate visual system. Most animals have visual systems that are ‘tuned’ differently to humans; optimized for different parts of the visible spectrum. To understand reef fish colours, we need to reconstruct the appearance of colourful patterns and backgrounds as they are seen through the eyes of fish. Here, the coral reef associated triggerfish, Rhinecanthus aculeatus, was tested behaviourally to determine the limits of its colour vision. This is the first demonstration of behavioural colour discrimination thresholds in a coral reef species and is a critical step in our understanding of communication and speciation in this vibrant colourful habitat. Fish were trained to discriminate between a reward colour stimulus and series of non-reward colour stimuli and the discrimination thresholds were found to correspond well with predictions based on the receptor noise limited visual model and anatomy of the eye. Colour discrimination abilities of both reef fish and a variety of animals can therefore now be predicted using the parameters described here. PMID:27703704

  17. Calibrating screens for continuous colour displays.

    PubMed

    Shepherd, A J

    1997-01-01

    This paper focuses on two issues that are important to those who use colour monitors for research in vision. One is concerned with the measurement and calibration of colour screens. To this end the luminance and chromaticity readings of a tri-filter colorimeter and a spectroradiometer are compared (both commonly used to calibrate screens). The second is concerned with screen interactions, whereby colours can be distorted from their expected or calculated values by the colours displayed in neighbouring areas. This issue is crucial for those who use measurements of the light emitted from the red, green and blue phosphors of a monitor in isolation to specify other colours on screen, particularly in the research areas of colour contrast and colour constancy, since the specified colours may not actually be displayed. Finally, an alternative calibration method is described that uses an iterative measurement procedure to obtain screen specifications that are accurate regardless of the display complexity, so that researchers can be confident that the required colours are actually displayed on the screen.

  18. Comparison of spread spectrum and pulse signal excitation for split spectrum techniques composite imaging

    NASA Astrophysics Data System (ADS)

    Svilainis, L.; Kitov, S.; Rodríguez, A.; Vergara, L.; Dumbrava, V.; Chaziachmetovas, A.

    2012-12-01

    Ultrasonic imaging of composites was investigated. Glass and carbon fiber reinforced plastic produced by resin transfer molding and prepreg forming were analyzed. In some of the samples air bubbles were trapped during RTM (resin transfer molding) process and interlayer gaps were present in prepreg technology samples. One of the most expected techniques to apply in such case is the Split Spectrum processing. On the other hand such signals require specific processing to reliably reconstruct the temporal position of the defect reflection. Correlation processing can be used for signal compression or Wiener filtering can be applied for spectral content equalisation. Pulse signals are simple to generate, but lack the possibility to alter the signal's spectrum shape. Spread spectrum signals offer a powerful tool for signal energy over frequency band increase and resolution enhancement. CW (continuous wave) burst has high energy but lacks the bandwidth needed for SSP (spread spectrum processing). The aim of the investigation was to compare the performance of the above signals in case of composite imaging, when various Split Spectrum Processing techniques are used with preceding Wiener processing for spectral content compensation. Resulting composite signals and images obtained are presented. Structural noise removal performance was evaluated as Receiver Operating Characteristics (ROC).

  19. A comparison of different approaches for imaging cracks in composites by X-ray microtomography.

    PubMed

    Yu, B; Bradley, R S; Soutis, C; Withers, P J

    2016-07-13

    X-ray computed tomography (CT) has emerged as a key imaging tool in the characterization of materials, allowing three-dimensional visualization of an object non-destructively as well as enabling the monitoring of damage accumulation over time through time-lapse imaging. However, small defects and cracks can be difficult to detect, particularly in composite materials where low-contrast, plate-like geometries of large area can compromise detectability. Here, we investigate a number of strategies aimed at increasing the capability of X-ray CT to detect composite damage such as transverse ply cracking and delamination, looking specifically at a woven glass fibre-reinforced three-dimensional composite. High-resolution region of interest (ROI) scanning, in situ loading, phase contrast and contrast agents are examined systematically as strategies for improving the defect detectability. Spatial resolution, contrast, signal-to-noise ratio, full width at half maximum, user friendliness and measurement time are all considered. Taken together, the results suggest that high-resolution ROI scanning combined with the increased contrast resulting from staining give the highest defect detectability. This article is part of the themed issue 'Multiscale modelling of the structural integrity of composite materials'. PMID:27242291

  20. A comparison of different approaches for imaging cracks in composites by X-ray microtomography.

    PubMed

    Yu, B; Bradley, R S; Soutis, C; Withers, P J

    2016-07-13

    X-ray computed tomography (CT) has emerged as a key imaging tool in the characterization of materials, allowing three-dimensional visualization of an object non-destructively as well as enabling the monitoring of damage accumulation over time through time-lapse imaging. However, small defects and cracks can be difficult to detect, particularly in composite materials where low-contrast, plate-like geometries of large area can compromise detectability. Here, we investigate a number of strategies aimed at increasing the capability of X-ray CT to detect composite damage such as transverse ply cracking and delamination, looking specifically at a woven glass fibre-reinforced three-dimensional composite. High-resolution region of interest (ROI) scanning, in situ loading, phase contrast and contrast agents are examined systematically as strategies for improving the defect detectability. Spatial resolution, contrast, signal-to-noise ratio, full width at half maximum, user friendliness and measurement time are all considered. Taken together, the results suggest that high-resolution ROI scanning combined with the increased contrast resulting from staining give the highest defect detectability. This article is part of the themed issue 'Multiscale modelling of the structural integrity of composite materials'.

  1. A comparison of different approaches for imaging cracks in composites by X-ray microtomography

    PubMed Central

    Yu, B.; Bradley, R. S.; Withers, P. J.

    2016-01-01

    X-ray computed tomography (CT) has emerged as a key imaging tool in the characterization of materials, allowing three-dimensional visualization of an object non-destructively as well as enabling the monitoring of damage accumulation over time through time-lapse imaging. However, small defects and cracks can be difficult to detect, particularly in composite materials where low-contrast, plate-like geometries of large area can compromise detectability. Here, we investigate a number of strategies aimed at increasing the capability of X-ray CT to detect composite damage such as transverse ply cracking and delamination, looking specifically at a woven glass fibre-reinforced three-dimensional composite. High-resolution region of interest (ROI) scanning, in situ loading, phase contrast and contrast agents are examined systematically as strategies for improving the defect detectability. Spatial resolution, contrast, signal-to-noise ratio, full width at half maximum, user friendliness and measurement time are all considered. Taken together, the results suggest that high-resolution ROI scanning combined with the increased contrast resulting from staining give the highest defect detectability. This article is part of the themed issue ‘Multiscale modelling of the structural integrity of composite materials’. PMID:27242291

  2. Symphony of colours in the Tarantula

    NASA Astrophysics Data System (ADS)

    2004-12-01

    hi-res Size hi-res: 1058 Kb Credits: ESA/NASA, ESO and Danny LaCrue Symphony of colours in the Tarantula The Tarantula is situated 170 000 light-years away in the Large Magellanic Cloud (LMC) in the southern sky and is clearly visible to the naked eye as a large milky patch. Astronomers believe that this smallish irregular galaxy is currently going through a violent period in its life. It is orbiting around the Milky Way and has had several close encounters with it. It is believed that the interaction with the Milky Way has caused an episode of energetic star formation - part of which is visible as the Tarantula Nebula. Just above the centre of the image there is a huge cluster of very hot stars called R136. The stars in R136 are also among the most massive stars we know. R136 is also a very young cluster, its oldest stars being 'just' 5 million years old or so. Its smallest stars, however, are still forming, so astronomers observe R136 to try to understand the early stages of stellar evolution. Near the lower edge of the image we find the star cluster Hodge 301. Hodge 301 is almost 10 times older than R136. Some of the stars in Hodge 301 are so old that they have already exploded as supernovae. The shockwave from this explosion has compressed the gas in the Tarantula into the filaments and sheets that are seen around the cluster. This mosaic of the Tarantula Nebula consists of images from the NASA/ESA Hubble Space Telescope’s Wide Field and Planetary Camera 2 (WFPC2) and was created by 23 year old amateur astronomer Danny LaCrue. The image was constructed by 15 individual exposures taken through three narrow-band filters allowing light from ionised oxygen (501 nm, shown as blue), hydrogen-alpha (656 nm, shown as green) and ionised sulphur (672 nm, shown as red). The exposure time for the individual WFPC2 images vary between 800 and 2800 seconds in each filter. The Hubble data have been superimposed onto images taken through matching narrow-band filters with the

  3. Fabrication and characterization of medical grade polyurethane composite catheters for near-infrared imaging.

    PubMed

    Stevenson, André T; Reese, Laura M; Hill, Tanner K; McGuire, Jeffrey; Mohs, Aaron M; Shekhar, Raj; Bickford, Lissett R; Whittington, Abby R

    2015-06-01

    Peripherally inserted central catheters (PICCs) are hollow polymeric tubes that transport nutrients, blood and medications to neonates. To determine proper PICC placement, frequent X-ray imaging of neonates is performed. Because X-rays pose severe health risks to neonates, safer alternatives are needed. We hypothesize that near infrared (NIR) polymer composites can be fabricated into catheters by incorporating a fluorescent dye (IRDye 800CW) and visualized using NIR imaging. To fabricate catheters, polymer and dye are dry mixed and pressed, sectioned, and extruded to produce hollow tubes. We analyzed surface roughness, stiffness, dye retention, NIR contrast intensity, and biocompatibility. The extrusion process did not significantly alter the mechanical properties of the polymer composites. Over a period of 23 days, only 6.35 ± 5.08% dye leached out of catheters. The addition of 0.025 wt% dye resulted in a 14-fold contrast enhancement producing clear PICC images at 1 cm under a tissue equivalent. The addition of IRDye 800CW did not alter the biocompatibility of the polymer and did not increase adhesion of cells to the surface. We successfully demonstrated that catheters can be imaged without the use of harmful radiation and still maintain the same properties as the unaltered medical grade equivalent.

  4. SNR enhancement for composite application using multiple Doppler vibrometers based laser ultrasonic propagation imager

    NASA Astrophysics Data System (ADS)

    Truong, Thanh Chung; Lee, Jung Ryul

    2016-09-01

    In recent years, the technology of using laser ultrasonic propagation imaging for damage visualization of composite structures were applied to real-world applications. Among many choices of sensor for the Ultrasonic Propagation Imager, the laser interferometry has several advantages: it is non-invasive, and portable, and with extraordinarily long-range measurement. However, the critical issue with interferometry sensing is its low signal-to-noise ratio (SNR), where the background noise can mask the damage-induced waves and making it impossible to identify the damages, especially in composite structures. In this paper, we propose a hardware-based SNR enhancement technique using multiple Laser Doppler Vibrometers (LDVs). The out-of-plane mode of ultrasonic signals are measured by multiple LDVs at a common sensing point and then averaged in real time. We showed that the SNR enhancement in experiments was consistent with the theoretical prediction, and also the test results showed a clear improvement for damage visualization of structures using Ultrasonic Wave Propagation Imaging and Ultrasonic Wavenumber Imaging algorithms.

  5. Fabrication and Characterization of Medical Grade Polyurethane Composite Catheters for Near-Infrared Imaging

    PubMed Central

    Stevenson, André T.; Reese, Laura M.; Hill, Tanner K.; McGuire, Jeffrey; Mohs, Aaron M.; Shekhar, Raj; Bickford, Lissett R.; Whittington, Abby R.

    2015-01-01

    Peripherally inserted central catheters (PICCs) are hollow polymeric tubes that transport nutrients, blood and medications to neonates. To determine proper PICC placement, frequent X-ray imaging of neonates is performed. Because X-rays pose severe health risks to neonates, safer alternatives are needed. We hypothesize that near infrared (NIR) polymer composites can be fabricated into catheters by incorporating a fluorescent dye (IRDye 800CW) and visualized using NIR imaging. To fabricate catheters, polymer and dye are dry mixed and pressed, sectioned, and extruded to produce hollow tubes. We analyzed surface roughness, stiffness, dye retention, NIR contrast intensity, and biocompatibility. The extrusion process did not significantly alter the mechanical properties of the polymer composites. Over a period of 23 days, only 6.35 ± 5.08% dye leached out of catheters. The addition of 0.025 wt% dye resulted in a 14-fold contrast enhancement producing clear PICC images at 1 cm under a tissue equivalent. The addition of IRDye 800CW did not alter the biocompatibility of the polymer and did not increase adhesion of cells to the surface. We successfully demonstrated that catheters can be imaged without the use of harmful radiation and still maintain the same properties as the unaltered medical grade equivalent. PMID:25907050

  6. Guided wave imaging for detection and evaluation of impact-induced delamination in composites

    NASA Astrophysics Data System (ADS)

    Tian, Zhenhua; Yu, Lingyu; Leckey, Cara; Seebo, Jeffrey

    2015-10-01

    In this paper, guided wavefield interactions with delamination damage in laminated composite panels are investigated. The frequency-wavenumber representations of the guided wavefields show that different wavenumbers are present in the delaminated plate, compared to a pristine case. The wavenumbers are correlated to trapped waves in the delamination region. Novel approaches for imaging the composite panels using guided waves are discussed and demonstrated for quantitative evaluation of the delamination damage. A filter reconstruction imaging method is shown to provide a rapid technique to locate delamination damage by showing where guided wave energy is trapped. A spatial wavenumber-based imaging algorithm is applied to calculate wavenumber values at each spatial location and highlights the delamination damage as regions with larger wavenumber values. The imaging approaches are demonstrated using experimental data from a plate with a simulated delamination (teflon insert) and from a plate containing impact-induced delamination damage. The methods are also applied to a multiple mode guided wave case to demonstrate application to complex wave cases.

  7. Artistic creation as stimulated by superimposed versus combined-composite visual images.

    PubMed

    Rothenberg, A

    1986-02-01

    The creative role of homospatial thinking in visual art was assessed in an experiment with 39 highly talented young artists. In order to compare the creative effects of visual elements occupying the same space with identical elements arrayed in a combined foreground and background organization, superimposed slide images were presented to a randomly selected portion of the subject group, and the other portion of the subject group viewed the same slide images constructed into a figure-ground composite. Both groups produced three drawings stimulated by the slide stimuli, and these drawings were independently judged by three art experts. Results were that drawings produced by the group exposed to the superimposed images were rated higher in creative potential than those stimulated by the figure-ground controls. These results extend previous experimental findings of a tendency toward homospatial thinking in creative individuals in literature and visual art.

  8. Occupational colour vision requirements for police officers.

    PubMed

    Birch, Jennifer; Chisholm, Catharine M

    2008-11-01

    Inclusion of public service professions in the UK Disability Discrimination Act in 2004 prompted a review of occupational colour vision requirements for police officers. Changes in the regulations which existed prior to 2003 were proposed. The aim of this study was to obtain the views of serving police officers in Northern Ireland on the importance of good colour discrimination in everyday police work and on the recruitment regulations for patrol constables introduced in 2003 in mainland UK. These views were obtained by means of a questionnaire and informal discussions. More than 65% of police officers who responded to the questionnaire considered that good colour vision was very important for effective policing. Fewer than 2% considered that colour vision was unimportant. Experienced police officers agreed that the employment of colour-deficient patrol constables, as permitted in the new regulations, would lead to reduced efficiency and organisational difficulties at the local level. A number of everyday activities were described which showed the need for accurate colour discrimination. The change in recruitment policy and the lack of clarity in the new regulations show inadequate appreciation of the needs of the occupation, of different types of colour vision anomalies and of the diagnostic function of colour vision tests. Failure to provide guidance on appropriate colour vision tests, examination procedures and counselling services is likely to result in inconsistent employment policies in different police forces. It is recommended that the colour vision standard in place prior to 2003 is reinstated at the recruitment stage. The Ishihara test should be used for screening, and colour-deficient applicants further examined with the Farnsworth D15 test as a replacement for the City University Test 2nd edition. PMID:19076554

  9. Advances in Mineral Dust Source Composition Measurement with Imaging Spectroscopy at the Salton Sea, CA

    NASA Astrophysics Data System (ADS)

    Green, R. O.; Realmuto, V. J.; Thompson, D. R.; Mahowald, N. M.; Pérez García-Pando, C.; Miller, R. L.; Clark, R. N.; Swayze, G. A.; Okin, G. S.

    2015-12-01

    Mineral dust emitted from the Earth's surface is a principal contributor to direct radiative forcing over the arid regions, where shifts in climate have a significant impact on agriculture, precipitation, and desert encroachment around the globe. Dust particles contribute to both positive and negative forcing, depending on the composition of the particles. Particle composition is a function of the surface mineralogy of dust source regions, but poor knowledge of surface mineralogy on regional to global scales limits the skill of Earth System models to predict shifts in regional climate around the globe. Earth System models include the source, emission, transport and deposition phases of the dust cycle. In addition to direct radiative forcing contributions, mineral dust impacts include indirect radiative forcing, modification of the albedo and melting rates of snow and ice, kinetics of tropospheric photochemistry, formation and deposition of acidic aerosols, supply of nutrients to aquatic and terrestrial ecosystems, and impact on human health and safety. We demonstrate the ability to map mineral dust source composition in the Salton Sea dust source region with imaging spectroscopy measurements acquired as part of the NASA HyspIRI preparatory airborne campaign. These new spectroscopically derived compositional measurements provide a six orders of magnitude improvement over current atlases for this dust source region and provide a pathfinder example for a remote measurement approach to address this critical dust composition gap for global Earth System models.

  10. Combining 3D optical imaging and dual energy absorptiometry to measure three compositional components.

    PubMed

    Malkov, Serghei; Shepherd, John

    2014-02-17

    We report on the design of the technique combining 3D optical imaging and dual-energy absorptiometry body scanning to estimate local body area compositions of three compartments. Dual-energy attenuation and body shape measures are used together to solve for the three compositional tissue thicknesses: water, lipid, and protein. We designed phantoms with tissue-like properties as our reference standards for calibration purposes. The calibration was created by fitting phantom values using non-linear regression of quadratic and truncated polynomials. Dual-energy measurements were performed on tissue-mimicking phantoms using a bone densitometer unit. The phantoms were made of materials shown to have similar x-ray attenuation properties of the biological compositional compartments. The components for the solid phantom were tested and their high energy/low energy attenuation ratios are in good correspondent to water, lipid, and protein for the densitometer x-ray region. The three-dimensional body shape was reconstructed from the depth maps generated by Microsoft Kinect for Windows. We used open-source Point Cloud Library and freeware software to produce dense point clouds. Accuracy and precision of compositional and thickness measures were calculated. The error contributions due to two modalities were estimated. The preliminary phantom composition and shape measurements are found to demonstrate the feasibility of the method proposed.

  11. Image analysis of the microstructure of pseudo-1-3 magnetostrictive composites

    NASA Astrophysics Data System (ADS)

    Dong, Xufeng; Qi, Min; Guan, Xinchun; Ou, Jinping

    2010-04-01

    Previous studies did by some scholars proved applying a magnetic field during the manufacture process of polymer-bonded Terfenol-D could orient the magnetic easy direction of the particles along the field direction and form a pseudo-1-3 structure. Compared to the 0-3 composites composed of Terfenol-D particles dispersed randomly in a polymer matrix, pseudo-1-3 magnetostrictive composites present much larger magnetostrictive performance. In this paper, magnetostrictive composites based on Terfenol-D particles in an unsaturated polyester resin matrix were fabricated under different magnetic fields. Magentostriction was tested and compared to get the detail effects of orientation fields on magnetostrictive properties of magnetostrictive composites. Scanning electron microscopy was used to observe their microstructures. Image analysis was applied to describe the microstructures. The distribution of the angles between the major axis of the particles and the magnetic field direction was used to evaluate the arrangement of particles in the matrix quantitatively. The results confirm particle chain-like structures in composites prepared under larger magnetic field, and show that particle arrangement changes with the strength of the orientation field, which is result in the changes of magnetostrictive performance.

  12. Combining 3D optical imaging and dual energy absorptiometry to measure three compositional components

    PubMed Central

    Malkov, Serghei; Shepherd, John

    2014-01-01

    We report on the design of the technique combining 3D optical imaging and dual-energy absorptiometry body scanning to estimate local body area compositions of three compartments. Dual-energy attenuation and body shape measures are used together to solve for the three compositional tissue thicknesses: water, lipid, and protein. We designed phantoms with tissue-like properties as our reference standards for calibration purposes. The calibration was created by fitting phantom values using non-linear regression of quadratic and truncated polynomials. Dual-energy measurements were performed on tissue-mimicking phantoms using a bone densitometer unit. The phantoms were made of materials shown to have similar x-ray attenuation properties of the biological compositional compartments. The components for the solid phantom were tested and their high energy/low energy attenuation ratios are in good correspondent to water, lipid, and protein for the densitometer x-ray region. The three-dimensional body shape was reconstructed from the depth maps generated by Microsoft Kinect for Windows. We used open-source Point Cloud Library and freeware software to produce dense point clouds. Accuracy and precision of compositional and thickness measures were calculated. The error contributions due to two modalities were estimated. The preliminary phantom composition and shape measurements are found to demonstrate the feasibility of the method proposed. PMID:25083118

  13. Combining 3D optical imaging and dual energy absorptiometry to measure three compositional components

    NASA Astrophysics Data System (ADS)

    Malkov, Serghei; Shepherd, John

    2014-02-01

    We report on the design of the technique combining 3D optical imaging and dual-energy absorptiometry body scanning to estimate local body area compositions of three compartments. Dual-energy attenuation and body shape measures are used together to solve for the three compositional tissue thicknesses: water, lipid, and protein. We designed phantoms with tissue-like properties as our reference standards for calibration purposes. The calibration was created by fitting phantom values using non-linear regression of quadratic and truncated polynomials. Dual-energy measurements were performed on tissue-mimicking phantoms using a bone densitometer unit. The phantoms were made of materials shown to have similar x-ray attenuation properties of the biological compositional compartments. The components for the solid phantom were tested and their high energy/low energy attenuation ratios are in good correspondent to water, lipid, and protein for the densitometer x-ray region. The three-dimensional body shape was reconstructed from the depth maps generated by Microsoft Kinect for Windows. We used open-source Point Cloud Library and freeware software to produce dense point clouds. Accuracy and precision of compositional and thickness measures were calculated. The error contributions due to two modalities were estimated. The preliminary phantom composition and shape measurements are found to demonstrate the feasibility of the method proposed.

  14. Monitoring the North Atlantic using ocean colour data

    NASA Astrophysics Data System (ADS)

    Fuentes-Yaco, C.; Caverhill, C.; Maass, H.; Porter, C.; White, GN, III

    2016-04-01

    The Remote Sensing Unit (RSU) at the Bedford Institute of Oceanography (BIO) has been monitoring the North Atlantic using ocean colour products for decades. Optical sensors used include CZCS, POLDER, SeaWiFS, MODIS/Aqua and MERIS. The monitoring area is defined by the Atlantic Zone Monitoring Program (AZMP) but certain products extend into Arctic waters, and all-Canadian waters which include the Pacific coast. RSU provides Level 3 images for various products in several formats and a range of temporal and spatial resolutions. Basic statistics for pre-defined areas of interest are compiled for each product. Climatologies and anomaly maps are also routinely produced, and custom products are delivered by request. RSU is involved in the generation of Level 4 products, such as characterizing the phenology of spring and fall phytoplankton blooms, computing primary production, using ocean colour to aid in EBSA (Ecologically and Biologically Significant Area) definition and developing habitat suitability maps. Upcoming operational products include maps of diatom distribution, biogeochemical province boundaries, and products from sensors such as VIIRS (Visible Infrared Imaging Radiometer Suite), OLCI (Ocean Land Colour Instrument), and PACE (Pre-Aerosol, Clouds and ocean Ecosystem) hyperspectral microsatellite mission.

  15. Analysis of ochres from Clearwell Caves: the role of particle size in determining colour

    NASA Astrophysics Data System (ADS)

    Marshall, Lisa-Jane R.; Williams, Joanne R.; Almond, Matthew J.; Atkinson, Samantha D. M.; Cook, Samantha R.; Matthews, Wendy; Mortimore, Joanne L.

    2005-01-01

    Three ochre samples ( A (orange-red in colour), B (red) and C (purple)) from Clearwell Caves, (Gloucestershire, UK) have been examined using an integrated analytical methodology based on the techniques of IR and diffuse reflectance UV-visible-NIR spectroscopy, X-ray diffraction, elemental analysis by ICP-AES and particle size analysis. It is shown that the chromophore in each case is haematite. The differences in colour may be accounted for by (i) different mineralogical and chemical composition in the case of the orange ochre, where higher levels of dolomite and copper are seen and (ii) an unusual particle size distribution in the case of the purple ochre. When the purple ochre was ground to give the same particle size distribution as the red ochre then the colours of the two samples became indistinguishable. An analysis has now been completed of a range of ochre samples with colours from yellow to purple from the important site of Clearwell Caves.

  16. Colour Mathematics: With Graphs and Numbers

    ERIC Educational Resources Information Center

    LoPresto, Michael C.

    2009-01-01

    The different combinations involved in additive and subtractive colour mixing can often be difficult for students to remember. Using transmission graphs for filters of the primary colours and a numerical scheme to write out the relationships are good exercises in analytical thinking that can help students recall the combinations rather than just…

  17. Colour mathematics: with graphs and numbers

    NASA Astrophysics Data System (ADS)

    Lo Presto, Michael C.

    2009-07-01

    The different combinations involved in additive and subtractive colour mixing can often be difficult for students to remember. Using transmission graphs for filters of the primary colours and a numerical scheme to write out the relationships are good exercises in analytical thinking that can help students recall the combinations rather than just attempting to memorize them.

  18. Brilliant Colours from a White Snow Cover

    ERIC Educational Resources Information Center

    Vollmer, Michael; Shaw, Joseph A

    2013-01-01

    Surprisingly colourful views are possible from sparkling white snow. It is well known that similarly colourful features can exist in the sky whenever appropriate ice crystals are around. However, the transition of light reflection and refraction from ice crystals in the air to reflection and refraction from those in snow on the ground is not…

  19. Representing Object Colour in Language Comprehension

    ERIC Educational Resources Information Center

    Connell, Louise

    2007-01-01

    Embodied theories of cognition hold that mentally representing something "red" engages the neural subsystems that respond to environmental perception of that colour. This paper examines whether implicit perceptual information on object colour is represented during sentence comprehension even though doing so does not necessarily facilitate task…

  20. Prevalence of colour blindness in young Jordanians.

    PubMed

    Al-Aqtum, M T; Al-Qawasmeh, M H

    2001-01-01

    Colour blindness is one of the common genetic disorders observed in all human populations. It is a sex-linked recessive trait. The genes are located on the X chromosome within the Xq28 band. 1,418 university students (1,200 female and 218 male) from Zarka Private University and the Hashemite University were randomly selected and tested for congenital red/green colour blindness, by using Ishihara pseudo-isochromatic colour plates. A total of 23 individuals were found to be colour blind. In females, 4 students (0.33%) were colour blind: 1 of them showed protanomalia, 1 protanopia and 2 deuteranomalia. In males, 19 students (8.72%) were colour blind: 4 showed protanomalia, 3 protanopia, 8 deuteranomalia and 4 deuteranopia. The allelic frequencies of the colour vision gene were found to be 0.087 in males, 0.003 in females and 0.016 in the total population. Studies on colour blindness in Jordan are very few; this population-based investigation is meant to fill a gap in this field.

  1. Novel Recognition Method of Blast Furnace Dust Composition by Multifeature Analysis Based on Comprehensive Image-Processing Techniques

    NASA Astrophysics Data System (ADS)

    Guo, Hongwei; Su, Buxin; Bai, Zhenlong; Zhang, Jianliang; Li, Xinyu

    2014-11-01

    The traditional artificial recognition methods for the blast furnace dust composition have several disadvantages, including a great deal of information to dispose, complex operation, and low working efficiency. In this article, a multifeature analysis method based on comprehensive image-processing techniques was proposed to automatically recognize the blast furnace dust composition. First, the artificial recognition and feature analysis, which included image preprocessing, Harris corner feature, Canny edge feature, and Ruffle feature analysis, was designed to build the template image, so that any unknown dust digital image could be tested. Second, the composition of coke, microvariation pulverized coal, vitric, ash, and iron from dust would be distinguished according to their different range of values based on the multifeature analysis. The method is valid for recognizing the blast furnace dust composition automatically, and it is fast and has a high recognition accuracy.

  2. Novel Recognition Method of Blast Furnace Dust Composition by Multifeature Analysis Based on Comprehensive Image-Processing Techniques

    NASA Astrophysics Data System (ADS)

    Guo, Hongwei; Su, Buxin; Bai, Zhenlong; Zhang, Jianliang; Li, Xinyu

    2014-09-01

    The traditional artificial recognition methods for the blast furnace dust composition have several disadvantages, including a great deal of information to dispose, complex operation, and low working efficiency. In this article, a multifeature analysis method based on comprehensive image-processing techniques was proposed to automatically recognize the blast furnace dust composition. First, the artificial recognition and feature analysis, which included image preprocessing, Harris corner feature, Canny edge feature, and Ruffle feature analysis, was designed to build the template image, so that any unknown dust digital image could be tested. Second, the composition of coke, microvariation pulverized coal, vitric, ash, and iron from dust would be distinguished according to their different range of values based on the multifeature analysis. The method is valid for recognizing the blast furnace dust composition automatically, and it is fast and has a high recognition accuracy.

  3. The coevolution theory of autumn colours.

    PubMed Central

    Archetti, Marco; Brown, Sam P.

    2004-01-01

    According to the coevolution theory of autumn colours, the bright colours of leaves in autumn are a warning signal to insects that lay their eggs on the trees in that season. If the colour is linked to the level of defensive commitment of the tree and the insects learn to avoid bright colours, this may lead to a coevolutionary process in which bright trees reduce their parasite load and choosy insects locate the most profitable hosts for the winter. We try to clarify what the theory actually says and to correct some misunderstandings that have been put forward. We also review current research on autumn colours and discuss what needs to be done to test the theory. PMID:15306345

  4. Worldwide patterns of bird colouration on islands.

    PubMed

    Doutrelant, Claire; Paquet, Matthieu; Renoult, Julien P; Grégoire, Arnaud; Crochet, Pierre-André; Covas, Rita

    2016-05-01

    Island environments share distinctive characteristics that offer unique opportunities to investigate parallel evolution. Previous research has produced evidence of an island syndrome for morphological traits, life-history strategies and ecological niches, but little is known about the response to insularity of other important traits such as animal signals. Here, we tested whether birds' plumage colouration is part of the island syndrome. We analysed with spectrophotometry the colouration of 116 species endemic to islands and their 116 closest mainland relatives. We found a pattern of reduced brightness and colour intensity for both sexes on islands. In addition, we found a decrease in the number of colour patches on islands that, in males, was associated with a decrease in the number of same-family sympatric species. These results demonstrate a worldwide pattern of parallel colour changes on islands and suggest that a relaxation of selection on species recognition may be one of the mechanisms involved.

  5. Identifying the source of colours in the Jovian atmosphere

    NASA Astrophysics Data System (ADS)

    Braude, Ashwin; Irwin, Patrick; Orton, Glenn S.; Fletcher, Leigh

    2016-10-01

    We wish to identify the source of Jupiter's colours through spectral analysis of images of Jupiter in the visible-to-near-infrared in conjunction with observations made by Juno in the mid-infrared and at super-high frequency. Three sets of observations were made of Jupiter by the MUSE integral-field spectrograph between 2014-2016 in the spectral range 0.48-0.93um, and reduced using a standard pipeline. Some large high-altitude hazes were observed in 2014 in the North Tropical Zone and the North Temperate Belt which appeared to have vanished by 2016. A single spectral image cube from 2014 was selected for analysis, and attempts at retrieving vertical cloud profiles, imaginary refractive indices and single-scattering albedos using the Nemesis radiative transfer model were made in different locations on Jupiter corresponding to the most prominent features close to the Equatorial region. Differences in lower tropospheric cloud altitude and opacity were found between the zones and the belts, and the belt cloud particles were seen to be significantly more blue-absorbing than the zone particles. Attempts were made at retrieving the real refractive index of the cloud particles in the upper tropospheric haze, where the majority of the colour-producing particles, or 'chromophores', are thought to be located, and values of refractive index greater than that of ammonia ice were observed, indicating the presence of a foreign substance. Further ground-based observations from MUSE in the visible and from TEXES in the mid-Infrared combined with localised observations from Juno later this year should shed more light on the origin of the colour-producing substance in the Jovian clouds, as well as of any seasonal changes in colour.

  6. Colour in insect thermoregulation: empirical and theoretical tests in the colour-changing grasshopper, Kosciuscola tristis.

    PubMed

    Umbers, K D L; Herberstein, M E; Madin, J S

    2013-01-01

    Body colours can result in different internal body temperatures, but evidence for the biological significance of colour-induced temperature differences is inconsistent. We investigated the relationship between body colour and temperature in a model insect species that rapidly changes colour. We used an empirical approach and constructed a heat budget model to quantify whether a colour change from black to turquoise has a role in thermoregulation for the chameleon grasshopper (Kosciuscola tristis). Our study shows that colour change in K. tristis provides relatively small temperature differences that vary greatly with wind speed (0.55 °C at ms(-1) to 0.05 °C at 10 ms(-1)). The biological significance of this difference is unclear and we discuss the requirement for more studies that directly test hypotheses regarding the fitness effects of colour in manipulating body temperature.

  7. A vector model of colour contrast in a cone-excitation colour space.

    PubMed

    Shepherd, A J

    1997-01-01

    A vector model of colour contrast is examined in a colour space that is a logarithmic transformation of the MacLeod-Boynton cone-excitation diagram. Observers set matches in a haploscopic display, in which one eye viewed a standard display (a neutral target square in a coloured surround) and the other viewed a matching display (a variable square in its own surround). Contrast colours are simply represented in this colour space: the vector connecting the right-eye surround and matched chromaticities is parallel to and to the same length and direction as the vector that connects the left-eye (standard) surround and square chromaticities. This describes observers' matches to the hues induced in a neutral square for a range of inducing surround colours, a range of right-eye (match) surround colours and four different luminance contrasts.

  8. Colour in insect thermoregulation: empirical and theoretical tests in the colour-changing grasshopper, Kosciuscola tristis.

    PubMed

    Umbers, K D L; Herberstein, M E; Madin, J S

    2013-01-01

    Body colours can result in different internal body temperatures, but evidence for the biological significance of colour-induced temperature differences is inconsistent. We investigated the relationship between body colour and temperature in a model insect species that rapidly changes colour. We used an empirical approach and constructed a heat budget model to quantify whether a colour change from black to turquoise has a role in thermoregulation for the chameleon grasshopper (Kosciuscola tristis). Our study shows that colour change in K. tristis provides relatively small temperature differences that vary greatly with wind speed (0.55 °C at ms(-1) to 0.05 °C at 10 ms(-1)). The biological significance of this difference is unclear and we discuss the requirement for more studies that directly test hypotheses regarding the fitness effects of colour in manipulating body temperature. PMID:23108152

  9. Anomaly detection in radiographic images of composite materials via crosshatch regression

    NASA Astrophysics Data System (ADS)

    Lockard, Colin D.

    The development and testing of new composite materials is an important area of research supporting advances in aerospace engineering. Understanding the properties of these materials requires the analysis of material samples to identify damage. Given the significant time and effort required from human experts to analyze computed tomography (CT) scans related to the non-destructive evaluation of carbon fiber materials, it is advantageous to develop an automated system for identifying anomalies in these images. This thesis introduces a regression-based algorithm for identifying anomalies in grayscale images, with a particular focus on its application for the analysis of CT scan images of carbon fiber. The algorithm centers around a "crosshatch regression" approach in which each two-dimensional image is divided into a series of one-dimensional signals, each representing a single line of pixels. A robust multiple linear regression model is fitted to each signal and outliers are identified. Smoothing and quality control techniques help better define anomaly boundaries and remove noise, and multiple crosshatch regression runs are combined to generate the final result. A ground truth set was created and the algorithm was run against these images for testing. The experimental results support the efficacy of the technique, locating 92% of anomalies with an average recall of 88%, precision of 78%, and root mean square deviation of 11.2 pixels.

  10. PROGRESS ON DEVELOPING SONIC INFRARED IMAGING FOR DEFECT DETECTION IN COMPOSITE STRUCTURES

    SciTech Connect

    Han Xiaoyan; He Qi; Li Wei; Newaz, Golam; Favro, Lawrence D.; Thomas, Robert L.

    2010-02-22

    At last year's QNDE conference, we presented our development of Sonic IR imaging technology in metal structures, with results from both experimental studies and theoretical computing. In the latest aircraft designs, such as the B787 from Boeing, composites have become the major materials in structures such as the fuselage and wings. This is in contrast to composites' use only in auxiliary components such as flaps and spoilers in the past. With today's advanced technology of fabrication, it is expected the new materials can be put in use in even more aircraft structures due to its light weight and high strength (high strength-to-weight ratio), high specific stiffness, tailorability of properties, design flexibility etc. Especially, with increases in fuel cost, reducing the aircraft's body weight becomes more and more appealing. In this presentation, we describe the progress on our development of Sonic IR imaging for aircraft composite structures. In particular, we describe the some unexpected results discovered while modeling delaminations. These results were later experimentally verified with an engineered delamination.

  11. Hand motion segmentation against skin colour background in breast awareness applications.

    PubMed

    Hu, Yuqin; Naguib, Raouf N G; Todman, Alison G; Amin, Saad A; Al-Omishy, Hassanein; Oikonomou, Andreas; Tucker, Nick

    2004-01-01

    Skin colour modelling and classification play significant roles in face and hand detection, recognition and tracking. A hand is an essential tool used in breast self-examination, which needs to be detected and analysed during the process of breast palpation. However, the background of a woman's moving hand is her breast that has the same or similar colour as the hand. Additionally, colour images recorded by a web camera are strongly affected by the lighting or brightness conditions. Hence, it is a challenging task to segment and track the hand against the breast without utilising any artificial markers, such as coloured nail polish. In this paper, a two-dimensional Gaussian skin colour model is employed in a particular way to identify a breast but not a hand. First, an input image is transformed to YCbCr colour space, which is less sensitive to the lighting conditions and more tolerant of skin tone. The breast, thus detected by the Gaussian skin model, is used as the baseline or framework for the hand motion. Secondly, motion cues are used to segment the hand motion against the detected baseline. Desired segmentation results have been achieved and the robustness of this algorithm is demonstrated in this paper. PMID:17270966

  12. Measurement and prediction of pork colour.

    PubMed

    Van Oeckel, M J; Warnants, N; Boucqué, C V

    1999-08-01

    The extent to which instrumental colour determinations by FOPu (light scattering), Göfo (reflectance) and Labscan II (CIE L*, CIE a* and CIE b*, hue and chroma) are related to the Japanese colour grades was studied. Additionally, four on-line methods: pH1, FOP1, PQM1 (conductivity) and DDLT (Double Density Light Transmission, analogous to Capteur Gras/Maigre), were evaluated for their ability to predict subjectively and objectively colour. One hundred and twenty samples of m. longissimus thoracis et lumborum, from animals of different genotypes, were analysed. Of the instrumental colour determinations, CIE L* (r=-0.82), FOPu (r=-0.70) and Göfo (r=0.70) were best correlated with the Japanese colour scores. The Japanese colour grades could be predicted by the on-line instruments, pH1, FOP1, PQM1 and DDLT, with determination coefficients between 15 and 28%. Ultimate meat colour, determined by Japanese colour standards, FOPu, Göfo and CIE L*, was better predicted by DDLT than by the classic on-line instruments: FOP1, pH1 and PQM1, although the standard error of the estimate was similar for all instruments. This means that DDLT, although originally designed for estimating lean meat percentage, can additionally give information about meat quality, in particular colour. However, it must be stressed that the colour estimate by DDLT refers to a population of animals, rather than to individual pigs, because of the number of erroneously assigned samples. PMID:22062695

  13. Plasmonic cavity-apertures as dynamic pixels for the simultaneous control of colour and intensity

    PubMed Central

    Yun, Hansik; Lee, Seung-Yeol; Hong, Keehoon; Yeom, Jiwoon; Lee, Byoungho

    2015-01-01

    Despite steady technological progress, displays are still subject to inherent limitations in resolution improvement and pixel miniaturization because a series of colours is generally expressed by a combination of at least three primary colour pixels. Here we propose a structure comprising a metal cavity and a nanoaperture, which we refer to as a cavity-aperture, to simultaneously control the colour and intensity of transmitted light in a single pixel. The metal cavity constructs plasmonic standing waves to organize the spatial distribution of amplitudes according to wavelength, and the nanoaperture permits light with a specific wavelength and amplitude to pass through it, depending on the nanoaperature's relative position in the cavity and the polarization state of the incident light. Therefore, the cavity-aperture has the potential to function as a dynamic colour pixel. This design method may be helpful in developing various photonic devices, such as micro-imaging systems and multiplexed sensors. PMID:25990071

  14. Arnheim's Gestalt theory of visual balance: Examining the compositional structure of art photographs and abstract images

    PubMed Central

    McManus, I C; Stöver, Katharina; Kim, Do

    2011-01-01

    In Art and Visual Perception, Rudolf Arnheim, following on from Denman Ross's A Theory of Pure Design, proposed a Gestalt theory of visual composition. The current paper assesses a physicalist interpretation of Arnheim's theory, calculating an image's centre of mass (CoM). Three types of data are used: a large, representative collection of art photographs of recognised quality; croppings by experts and non-experts of photographs; and Ross and Arnheim's procedure of placing a frame around objects such as Arnheim's two black disks. Compared with control images, the CoM of art photographs was closer to an axis (horizontal, vertical, or diagonal), as was the case for photographic croppings. However, stronger, within-image, paired comparison studies, comparing art photographs with the CoM moved on or off an axis (the ‘gamma-ramp study’), or comparing adjacent croppings on or off an axis (the ‘spider-web study’), showed no support for the Arnheim–Ross theory. Finally, studies moving a frame around two disks, of different size, greyness, or background, did not support Arnheim's Gestalt theory. Although the detailed results did not support the Arnheim–Ross theory, several significant results were found which clearly require explanation by any adequate theory of the aesthetics of visual composition. PMID:23145250

  15. Damage imaging in a laminated composite plate using an air-coupled time reversal mirror

    SciTech Connect

    Le Bas, P. -Y.; Remillieux, M. C.; Pieczonka, L.; Ten Cate, J. A.; Anderson, B. E.; Ulrich, T. J.

    2015-11-03

    We demonstrate the possibility of selectively imaging the features of a barely visible impact damage in a laminated composite plate by using an air-coupled time reversal mirror. The mirror consists of a number of piezoelectric transducers affixed to wedges of power law profiles, which act as unconventional matching layers. The transducers are enclosed in a hollow reverberant cavity with an opening to allow progressive emission of the ultrasonic wave field towards the composite plate. The principle of time reversal is used to focus elastic waves at each point of a scanning grid spanning the surface of the plate, thus allowing localized inspection at each of these points. The proposed device and signal processing removes the need to be in direct contact with the plate and reveals the same features as vibrothermography and more features than a C-scan. More importantly, this device can decouple the features of the defect according to their orientation, by selectively focusing vector components of motion into the object, through air. For instance, a delamination can be imaged in one experiment using out-of-plane focusing, whereas a crack can be imaged in a separate experiment using in-plane focusing. As a result, this capability, inherited from the principle of time reversal, cannot be found in conventional air-coupled transducers.

  16. Damage imaging in a laminated composite plate using an air-coupled time reversal mirror

    DOE PAGES

    Le Bas, P. -Y.; Remillieux, M. C.; Pieczonka, L.; Ten Cate, J. A.; Anderson, B. E.; Ulrich, T. J.

    2015-11-03

    We demonstrate the possibility of selectively imaging the features of a barely visible impact damage in a laminated composite plate by using an air-coupled time reversal mirror. The mirror consists of a number of piezoelectric transducers affixed to wedges of power law profiles, which act as unconventional matching layers. The transducers are enclosed in a hollow reverberant cavity with an opening to allow progressive emission of the ultrasonic wave field towards the composite plate. The principle of time reversal is used to focus elastic waves at each point of a scanning grid spanning the surface of the plate, thus allowingmore » localized inspection at each of these points. The proposed device and signal processing removes the need to be in direct contact with the plate and reveals the same features as vibrothermography and more features than a C-scan. More importantly, this device can decouple the features of the defect according to their orientation, by selectively focusing vector components of motion into the object, through air. For instance, a delamination can be imaged in one experiment using out-of-plane focusing, whereas a crack can be imaged in a separate experiment using in-plane focusing. As a result, this capability, inherited from the principle of time reversal, cannot be found in conventional air-coupled transducers.« less

  17. Arnheim's Gestalt theory of visual balance: Examining the compositional structure of art photographs and abstract images.

    PubMed

    McManus, I C; Stöver, Katharina; Kim, Do

    2011-01-01

    In Art and Visual Perception, Rudolf Arnheim, following on from Denman Ross's A Theory of Pure Design, proposed a Gestalt theory of visual composition. The current paper assesses a physicalist interpretation of Arnheim's theory, calculating an image's centre of mass (CoM). Three types of data are used: a large, representative collection of art photographs of recognised quality; croppings by experts and non-experts of photographs; and Ross and Arnheim's procedure of placing a frame around objects such as Arnheim's two black disks. Compared with control images, the CoM of art photographs was closer to an axis (horizontal, vertical, or diagonal), as was the case for photographic croppings. However, stronger, within-image, paired comparison studies, comparing art photographs with the CoM moved on or off an axis (the 'gamma-ramp study'), or comparing adjacent croppings on or off an axis (the 'spider-web study'), showed no support for the Arnheim-Ross theory. Finally, studies moving a frame around two disks, of different size, greyness, or background, did not support Arnheim's Gestalt theory. Although the detailed results did not support the Arnheim-Ross theory, several significant results were found which clearly require explanation by any adequate theory of the aesthetics of visual composition.

  18. Damage imaging in a laminated composite plate using an air-coupled time reversal mirror

    NASA Astrophysics Data System (ADS)

    Le Bas, P.-Y.; Remillieux, M. C.; Pieczonka, L.; Ten Cate, J. A.; Anderson, B. E.; Ulrich, T. J.

    2015-11-01

    We demonstrate the possibility of selectively imaging the features of a barely visible impact damage in a laminated composite plate by using an air-coupled time reversal mirror. The mirror consists of a number of piezoelectric transducers affixed to wedges of power law profiles, which act as unconventional matching layers. The transducers are enclosed in a hollow reverberant cavity with an opening to allow progressive emission of the ultrasonic wave field towards the composite plate. The principle of time reversal is used to focus elastic waves at each point of a scanning grid spanning the surface of the plate, thus allowing localized inspection at each of these points. The proposed device and signal processing removes the need to be in direct contact with the plate and reveals the same features as vibrothermography and more features than a C-scan. More importantly, this device can decouple the features of the defect according to their orientation, by selectively focusing vector components of motion into the object, through air. For instance, a delamination can be imaged in one experiment using out-of-plane focusing, whereas a crack can be imaged in a separate experiment using in-plane focusing. This capability, inherited from the principle of time reversal, cannot be found in conventional air-coupled transducers.

  19. Quantitative imaging of chemical composition using dual-energy, dual-source CT

    NASA Astrophysics Data System (ADS)

    Liu, Xin; Primak, Andrew N.; Yu, Lifeng; McCollough, Cynthia H.; Morin, Richard L.

    2008-03-01

    Dual-energy x-ray material decomposition has been proposed as a noninvasive quantitative imaging technique for more than 20 years. In this paper, we summarize previously developed dual-energy material decomposition methods and propose a simple yet accurate method for quantitatively measuring chemical composition in vivo. In order to take advantage of the newly developed dual-source CT, the proposed method is based upon post reconstruction (image space) data. Different from other post reconstruction methods, this method is designed to directly measure element composition (mass fraction) in a tissue by a simple table lookup procedure. The method has been tested in phantom studies and also applied to a clinical case. The results showed that this method is capable of accurately measuring elemental concentrations, such as iron in tissue, under low noise imaging conditions. The advantage of this method lies in its simplicity and fast processing times. We believe that this method can be applied clinically to measure the mass fraction of any chemical element in a two-material object, such as to quantify the iron overload in the liver (hemochromatosis). Further investigations on de-noising techniques, as well as clinical validation, are merited.

  20. Determining thermal diffusivity and defect attributes in ceramic matrix composites by infrared imaging

    NASA Astrophysics Data System (ADS)

    Ahuja, Sanjay; Ellingson, William A.; Stuckey, J. B.; Koehl, E. R.

    1996-03-01

    Ceramic matrix composites are being developed for numerous high temperature applications, including rotors and combustors for advanced turbine engines, heat exchanger and hot-gas filters for coal gasification plants. Among the materials of interest are silicon-carbide-fiber- reinforced-silicon-carbide (SiC(f)/SiC), silicon-carbide-fiber-reinforced-silicon-nitride (SiC(f)/Si3N4), aluminum-oxide-reinforced-alumina (Al2O3(f)/Al2O3, etc. In the manufacturing of these ceramic composites, the conditions of the fiber/matrix interface are critical to the mechanical and thermal behavior of the component. Defects such as delaminations and non-uniform porosity can directly affect the performance. A nondestructive evaluation (NDE) method, developed at Argonne National Laboratory has proved beneficial in analyzing as-processed conditions and defect detection created during manufacturing. This NDE method uses infrared thermal imaging for full-field quantitative measurement of the distribution of thermal diffusivity in large components. Intensity transform algorithms have been used for contrast enhancement of the output image. Nonuniformity correction and automatic gain control are used to dynamically optimize video contrast and brightness, providing additional resolution in the acquired images. Digital filtering, interpolation, and least-squares-estimation techniques have been incorporated for noise reduction and data acquisition. The Argonne NDE system has been utilized to determine thermal shock damage, density variations, and variations in fiber coating in a full array of test specimens.

  1. A brief discussion about image quality and SEM methods for quantitative fractography of polymer composites.

    PubMed

    Hein, L R O; Campos, K A; Caltabiano, P C R O; Kostov, K G

    2013-01-01

    The methodology for fracture analysis of polymeric composites with scanning electron microscopes (SEM) is still under discussion. Many authors prefer to use sputter coating with a conductive material instead of applying low-voltage (LV) or variable-pressure (VP) methods, which preserves the original surfaces. The present work examines the effects of sputter coating with 25 nm of gold on the topography of carbon-epoxy composites fracture surfaces, using an atomic force microscope. Also, the influence of SEM imaging parameters on fractal measurements is evaluated for the VP-SEM and LV-SEM methods. It was observed that topographic measurements were not significantly affected by the gold coating at tested scale. Moreover, changes on SEM setup leads to nonlinear outcome on texture parameters, such as fractal dimension and entropy values. For VP-SEM or LV-SEM, fractal dimension and entropy values did not present any evident relation with image quality parameters, but the resolution must be optimized with imaging setup, accompanied by charge neutralization.

  2. High resolution VIMS images of Titan's surface: implications for its composition, internal structure and dynamics

    NASA Astrophysics Data System (ADS)

    Sotin, C.; Le Mouelic, S.; Le Corre, L.; Barnes, J.; Brown, R. H.; Jaumann, R.; Buratti, B.; Baines, K.; Clark, R.; Nicholson, P.; Soderblom, L.

    2008-12-01

    With a field of view of 0.5 mrad per pixel, the VIMS (Visual and Infrared Mapping Spectrometer) onboard the Cassini spacecraft can acquire images with a resolution of 500 m per pixel at closest approach during a typical Titan flyby. This resolution is comparable to the resolution of the radar instrument and allows comparisons between the radar images and optical images in the six infrared windows where the surface can be observed. Such opportunities were not set up for the nominal tour before Saturn insertion. The opportunity was offered during the TA flyby [Sotin et al., Nature, 2005] and the results lead the Cassini program to give VIMS the prime observations during closest approach at the T24 and T38 flybys. Two different implementations were experienced. During the T24 flyby (01/29/2007), we used a push-broom mode allowing VIMS to image a long path before pointing to a specific site at the limit between the light and dark terrains. This observation allowed us to see the dunes and to infer some information on their composition [Barnes et al., Icarus, 2008], to image channels and to infer information of erosion processes of the bright equatorial regions [Jaumann et al., Icarus, in press] and to observe the strong correlation between radar images and the VIMS images over a bright area interpreted as a flow feature [Lopes et al., Icarus, 2007]. During the T38 flyby over Ontario Lacus (12/05/2007), it was decided to point to the lake and get different images which provide us with a set of observations obtained with different emergence angles. This observation allowed us to infer the liquid nature of the lake and the composition of the lake [Brown et al., Nature, 2008]. In addition, this mode gives good information on the atmospheric component and will help us remove that component to get better spectra of Titan's surface. During the extended mission, two observations are forecasted at the beginning and at the end of the Cassini Equinox Mission. The first one will

  3. Modeling dental composite shrinkage by digital image correlation and finite element methods

    NASA Astrophysics Data System (ADS)

    Chen, Terry Yuan-Fang; Huang, Pin-Sheng; Chuang, Shu-Fen

    2014-10-01

    Dental composites are light-curable resin-based materials with an inherent defect of polymerization shrinkage which may cause tooth deflection and debonding of restorations. This study aimed to combine digital image correlation (DIC) and finite element analysis (FEA) to model the shrinkage behaviors under different light curing regimens. Extracted human molars were prepared with proximal cavities for composite restorations, and then divided into three groups to receive different light curing protocols: regular intensity, low intensity, and step-curing consisting of low and high intensities. For each tooth, the composite fillings were consecutively placed under both unbonded and bonded conditions. At first, the shrinkage of the unbonded restorations was analyzed by DIC and adopted as the setting of FEA. The simulated shrinkage behaviors obtained from FEA were further validated by the measurements in the bonded cases. The results showed that different light curing regimens affected the shrinkage in unbonded restorations, with regular intensity showing the greatest shrinkage strain on the top surface. The shrinkage centers in the bonded cases were located closer to the cavity floor than those in the unbonded cases, and were less affected by curing regimens. The FEA results showed that the stress was modulated by the accumulated light energy density, while step-curing may alleviate the tensile stress along the cavity walls. In this study, DIC provides a complete description of the polymerization shrinkage behaviors of dental composites, which may facilitate the stress analysis in the numerical investigation.

  4. Development of Laser Desorption Imaging Mass Spectrometry Methods to Investigate the Molecular Composition of Latent Fingermarks

    NASA Astrophysics Data System (ADS)

    Lauzon, Nidia; Dufresne, Martin; Chauhan, Vinita; Chaurand, Pierre

    2015-06-01

    For a century, fingermark analysis has been one of the most important and common methods in forensic investigations. Modern chemical analysis technologies have added the potential to determine the molecular composition of fingermarks and possibly identify chemicals a suspect may have come into contact with. Improvements in analytical detection of the molecular composition of fingermarks is therefore of great importance. In this regard, matrix-assisted laser desorption ionization (MALDI) and laser desorption ionization (LDI) imaging mass spectrometry (IMS) have proven to be useful technologies for fingermark analysis. In these analyses, the choice of ionizing agent and its mode of deposition are critical steps for the identification of molecular markers. Here we propose two novel and complementary IMS approaches for endogenous and exogenous substance detection in fingermarks: sublimation of 2-mercaptobenzothiazol (2-MBT) matrix and silver sputtering.

  5. Use of discrete chromatic space to tune the image tone in a color image mosaic

    NASA Astrophysics Data System (ADS)

    Zhang, Zuxun; Li, Zhijiang; Zhang, Jianqing; Zheng, Li

    2003-09-01

    Color image process is a very important problem. However, the main approach presently of them is to transfer RGB colour space into another colour space, such as HIS (Hue, Intensity and Saturation). YIQ, LUV and so on. Virutally, it may not be a valid way to process colour airborne image just in one colour space. Because the electromagnetic wave is physically altered in every wave band, while the color image is perceived based on psychology vision. Therefore, it's necessary to propose an approach accord with physical transformation and psychological perception. Then, an analysis on how to use relative colour spaces to process colour airborne photo is discussed and an application on how to tune the image tone in colour airborne image mosaic is introduced. As a practice, a complete approach to perform the mosaic on color airborne images via taking full advantage of relative color spaces is discussed in the application.

  6. A complex carotenoid palette tunes avian colour vision

    PubMed Central

    Toomey, Matthew B.; Collins, Aaron M.; Frederiksen, Rikard; Cornwall, M. Carter; Timlin, Jerilyn A.; Corbo, Joseph C.

    2015-01-01

    The brilliantly coloured cone oil droplets of the avian retina function as long-pass cut-off filters that tune the spectral sensitivity of the photoreceptors and are hypothesized to enhance colour discrimination and improve colour constancy. Although it has long been known that these droplets are pigmented with carotenoids, their precise composition has remained uncertain owing to the technical challenges of measuring these very small, dense and highly refractile optical organelles. In this study, we integrated results from high-performance liquid chromatography, hyperspectral microscopy and microspectrophotometry to obtain a comprehensive understanding of oil droplet carotenoid pigmentation in the chicken (Gallus gallus). We find that each of the four carotenoid-containing droplet types consists of a complex mixture of carotenoids, with a single predominant carotenoid determining the wavelength of the spectral filtering cut-off. Consistent with previous reports, we find that the predominant carotenoid type in the oil droplets of long-wavelength-sensitive, medium-wavelength-sensitive and short-wavelength-sensitive type 2 cones are astaxanthin, zeaxanthin and galloxanthin, respectively. In addition, the oil droplet of the principal member of the double cone contains a mixture of galloxanthin and two hydroxycarotenoids (lutein and zeaxanthin). Short-wavelength-absorbing apocarotenoids are present in all of the droplet types, providing filtering of light in a region of the spectrum where filtering by hydroxy- and ketocarotenoids may be incomplete. Thus, birds rely on a complex palette of carotenoid pigments within their cone oil droplets to achieve finely tuned spectral filtering. PMID:26446559

  7. A complex carotenoid palette tunes avian colour vision.

    PubMed

    Toomey, Matthew B; Collins, Aaron M; Frederiksen, Rikard; Cornwall, M Carter; Timlin, Jerilyn A; Corbo, Joseph C

    2015-10-01

    The brilliantly coloured cone oil droplets of the avian retina function as long-pass cut-off filters that tune the spectral sensitivity of the photoreceptors and are hypothesized to enhance colour discrimination and improve colour constancy. Although it has long been known that these droplets are pigmented with carotenoids, their precise composition has remained uncertain owing to the technical challenges of measuring these very small, dense and highly refractile optical organelles. In this study, we integrated results from high-performance liquid chromatography, hyperspectral microscopy and microspectrophotometry to obtain a comprehensive understanding of oil droplet carotenoid pigmentation in the chicken (Gallus gallus). We find that each of the four carotenoid-containing droplet types consists of a complex mixture of carotenoids, with a single predominant carotenoid determining the wavelength of the spectral filtering cut-off. Consistent with previous reports, we find that the predominant carotenoid type in the oil droplets of long-wavelength-sensitive, medium-wavelength-sensitive and short-wavelength-sensitive type 2 cones are astaxanthin, zeaxanthin and galloxanthin, respectively. In addition, the oil droplet of the principal member of the double cone contains a mixture of galloxanthin and two hydroxycarotenoids (lutein and zeaxanthin). Short-wavelength-absorbing apocarotenoids are present in all of the droplet types, providing filtering of light in a region of the spectrum where filtering by hydroxy- and ketocarotenoids may be incomplete. Thus, birds rely on a complex palette of carotenoid pigments within their cone oil droplets to achieve finely tuned spectral filtering. PMID:26446559

  8. Colour as a signal for entraining the mammalian circadian clock.

    PubMed

    Walmsley, Lauren; Hanna, Lydia; Mouland, Josh; Martial, Franck; West, Alexander; Smedley, Andrew R; Bechtold, David A; Webb, Ann R; Lucas, Robert J; Brown, Timothy M

    2015-04-01

    Twilight is characterised by changes in both quantity ("irradiance") and quality ("colour") of light. Animals use the variation in irradiance to adjust their internal circadian clocks, aligning their behaviour and physiology with the solar cycle. However, it is currently unknown whether changes in colour also contribute to this entrainment process. Using environmental measurements, we show here that mammalian blue-yellow colour discrimination provides a more reliable method of tracking twilight progression than simply measuring irradiance. We next use electrophysiological recordings to demonstrate that neurons in the mouse suprachiasmatic circadian clock display the cone-dependent spectral opponency required to make use of this information. Thus, our data show that some clock neurons are highly sensitive to changes in spectral composition occurring over twilight and that this input dictates their response to changes in irradiance. Finally, using mice housed under photoperiods with simulated dawn/dusk transitions, we confirm that spectral changes occurring during twilight are required for appropriate circadian alignment under natural conditions. Together, these data reveal a new sensory mechanism for telling time of day that would be available to any mammalian species capable of chromatic vision.

  9. A complex carotenoid palette tunes avian colour vision.

    PubMed

    Toomey, Matthew B; Collins, Aaron M; Frederiksen, Rikard; Cornwall, M Carter; Timlin, Jerilyn A; Corbo, Joseph C

    2015-10-01

    The brilliantly coloured cone oil droplets of the avian retina function as long-pass cut-off filters that tune the spectral sensitivity of the photoreceptors and are hypothesized to enhance colour discrimination and improve colour constancy. Although it has long been known that these droplets are pigmented with carotenoids, their precise composition has remained uncertain owing to the technical challenges of measuring these very small, dense and highly refractile optical organelles. In this study, we integrated results from high-performance liquid chromatography, hyperspectral microscopy and microspectrophotometry to obtain a comprehensive understanding of oil droplet carotenoid pigmentation in the chicken (Gallus gallus). We find that each of the four carotenoid-containing droplet types consists of a complex mixture of carotenoids, with a single predominant carotenoid determining the wavelength of the spectral filtering cut-off. Consistent with previous reports, we find that the predominant carotenoid type in the oil droplets of long-wavelength-sensitive, medium-wavelength-sensitive and short-wavelength-sensitive type 2 cones are astaxanthin, zeaxanthin and galloxanthin, respectively. In addition, the oil droplet of the principal member of the double cone contains a mixture of galloxanthin and two hydroxycarotenoids (lutein and zeaxanthin). Short-wavelength-absorbing apocarotenoids are present in all of the droplet types, providing filtering of light in a region of the spectrum where filtering by hydroxy- and ketocarotenoids may be incomplete. Thus, birds rely on a complex palette of carotenoid pigments within their cone oil droplets to achieve finely tuned spectral filtering.

  10. Three-Dimensional Digital Image Correlation of a Composite Overwrapped Pressure Vessel During Hydrostatic Pressure Tests

    NASA Technical Reports Server (NTRS)

    Revilock, Duane M., Jr.; Thesken, John C.; Schmidt, Timothy E.

    2007-01-01

    Ambient temperature hydrostatic pressurization tests were conducted on a composite overwrapped pressure vessel (COPV) to understand the fiber stresses in COPV components. Two three-dimensional digital image correlation systems with high speed cameras were used in the evaluation to provide full field displacement and strain data for each pressurization test. A few of the key findings will be discussed including how the principal strains provided better insight into system behavior than traditional gauges, a high localized strain that was measured where gages were not present and the challenges of measuring curved surfaces with the use of a 1.25 in. thick layered polycarbonate panel that protected the cameras.

  11. Using composite images to assess accuracy in personality attribution to faces.

    PubMed

    Little, Anthony C; Perrett, David I

    2007-02-01

    Several studies have demonstrated some accuracy in personality attribution using only visual appearance. Using composite images of those scoring high and low on a particular trait, the current study shows that judges perform better than chance in guessing others' personality, particularly for the traits conscientiousness and extraversion. This study also shows that attractiveness, masculinity and age may all provide cues to assess personality accurately and that accuracy is affected by the sex of both of those judging and being judged. Individuals do perform better than chance at guessing another's personality from only facial information, providing some support for the popular belief that it is possible to assess accurately personality from faces. PMID:17319053

  12. Imaging latex-carbon nanotube composites by subsurface electrostatic force microscopy.

    PubMed

    Patel, Sajan; Petty, Clayton W; Krafcik, Karen; Loyola, Bryan; O'Bryan, Greg; Friddle, Raymond W

    2016-10-14

    Electrostatic modes of atomic force microscopy have shown to be non-destructive and relatively simple methods for imaging conductors embedded in insulating polymers. Here we use electrostatic force microscopy to image the dispersion of carbon nanotubes in a latex-based conductive composite, which brings forth features not observed in previously studied systems employing linear polymer films. A fixed-potential model of the probe-nanotube electrostatics is presented which in principle gives access to the conductive nanoparticle's depth and radius, and the polymer film dielectric constant. Comparing this model to the data results in nanotube depths that appear to be slightly above the film-air interface. This result suggests that water-mediated charge build-up at the film-air interface may be the source of electrostatic phase contrast in ambient conditions. PMID:27607079

  13. Imaging latex-carbon nanotube composites by subsurface electrostatic force microscopy.

    PubMed

    Patel, Sajan; Petty, Clayton W; Krafcik, Karen; Loyola, Bryan; O'Bryan, Greg; Friddle, Raymond W

    2016-10-14

    Electrostatic modes of atomic force microscopy have shown to be non-destructive and relatively simple methods for imaging conductors embedded in insulating polymers. Here we use electrostatic force microscopy to image the dispersion of carbon nanotubes in a latex-based conductive composite, which brings forth features not observed in previously studied systems employing linear polymer films. A fixed-potential model of the probe-nanotube electrostatics is presented which in principle gives access to the conductive nanoparticle's depth and radius, and the polymer film dielectric constant. Comparing this model to the data results in nanotube depths that appear to be slightly above the film-air interface. This result suggests that water-mediated charge build-up at the film-air interface may be the source of electrostatic phase contrast in ambient conditions.

  14. Imaging latex-carbon nanotube composites by subsurface electrostatic force microscopy

    NASA Astrophysics Data System (ADS)

    Patel, Sajan; Petty, Clayton W.; Krafcik, Karen; Loyola, Bryan; O'Bryan, Greg; Friddle, Raymond W.

    2016-10-01

    Electrostatic modes of atomic force microscopy have shown to be non-destructive and relatively simple methods for imaging conductors embedded in insulating polymers. Here we use electrostatic force microscopy to image the dispersion of carbon nanotubes in a latex-based conductive composite, which brings forth features not observed in previously studied systems employing linear polymer films. A fixed-potential model of the probe-nanotube electrostatics is presented which in principle gives access to the conductive nanoparticle’s depth and radius, and the polymer film dielectric constant. Comparing this model to the data results in nanotube depths that appear to be slightly above the film-air interface. This result suggests that water-mediated charge build-up at the film-air interface may be the source of electrostatic phase contrast in ambient conditions.

  15. Artificial selection for food colour preferences.

    PubMed

    Cole, Gemma L; Endler, John A

    2015-04-01

    Colour is an important factor in food detection and acquisition by animals using visually based foraging. Colour can be used to identify the suitability of a food source or improve the efficiency of food detection, and can even be linked to mate choice. Food colour preferences are known to exist, but whether these preferences are heritable and how these preferences evolve is unknown. Using the freshwater fish Poecilia reticulata, we artificially selected for chase behaviour towards two different-coloured moving stimuli: red and blue spots. A response to selection was only seen for chase behaviours towards the red, with realized heritabilities ranging from 0.25 to 0.30. Despite intense selection, no significant chase response was recorded for the blue-selected lines. This lack of response may be due to the motion-detection mechanism in the guppy visual system and may have novel implications for the evolvability of responses to colour-related signals. The behavioural response to several colours after five generations of selection suggests that the colour opponency system of the fish may regulate the response to selection. PMID:25740894

  16. Artificial selection for food colour preferences

    PubMed Central

    Cole, Gemma L.; Endler, John A.

    2015-01-01

    Colour is an important factor in food detection and acquisition by animals using visually based foraging. Colour can be used to identify the suitability of a food source or improve the efficiency of food detection, and can even be linked to mate choice. Food colour preferences are known to exist, but whether these preferences are heritable and how these preferences evolve is unknown. Using the freshwater fish Poecilia reticulata, we artificially selected for chase behaviour towards two different-coloured moving stimuli: red and blue spots. A response to selection was only seen for chase behaviours towards the red, with realized heritabilities ranging from 0.25 to 0.30. Despite intense selection, no significant chase response was recorded for the blue-selected lines. This lack of response may be due to the motion-detection mechanism in the guppy visual system and may have novel implications for the evolvability of responses to colour-related signals. The behavioural response to several colours after five generations of selection suggests that the colour opponency system of the fish may regulate the response to selection. PMID:25740894

  17. Physicochemical and physiological basis of dichromatic colour

    NASA Astrophysics Data System (ADS)

    Kreft, Samo; Kreft, Marko

    2007-11-01

    Out of three perceptual characteristics of the colour of any substance, the hue depends mostly on the spectral properties of a substance, while the brightness and saturation depend also on the concentration of a substance and its thickness. Here, we report that evident change of the hue of the colour (i.e., from green to red) is due to a change in concentration or the thickness of a layer in some exceptional substances such as pumpkin seed oil or an aqueous solution of bromophenol blue. In some regions of Central Europe, salad dressing is made preferably with the pumpkin seed oil, which has a strong characteristic nut-like taste and remarkable properties of the colour: it appears red in a bottle, but green when served as a salad dressing. The colour of the pumpkin seed oil was previously described as brownish yellow, dark green, dark green to red ochre or dark reddish brown to light yellow green. We elucidated the physicochemical and physiological basis of such dichromatism by Beer-Lambert law and by the characteristics of human colour perception. Our concept was corroborated by the outcome of calculations of colour from spectral properties using colour matching functions. We found that dichromatism is observed if the absorption spectrum of any substance has at least two local minima: one wide but shallow and one narrow but deep local minimum.

  18. Artificial selection for food colour preferences.

    PubMed

    Cole, Gemma L; Endler, John A

    2015-04-01

    Colour is an important factor in food detection and acquisition by animals using visually based foraging. Colour can be used to identify the suitability of a food source or improve the efficiency of food detection, and can even be linked to mate choice. Food colour preferences are known to exist, but whether these preferences are heritable and how these preferences evolve is unknown. Using the freshwater fish Poecilia reticulata, we artificially selected for chase behaviour towards two different-coloured moving stimuli: red and blue spots. A response to selection was only seen for chase behaviours towards the red, with realized heritabilities ranging from 0.25 to 0.30. Despite intense selection, no significant chase response was recorded for the blue-selected lines. This lack of response may be due to the motion-detection mechanism in the guppy visual system and may have novel implications for the evolvability of responses to colour-related signals. The behavioural response to several colours after five generations of selection suggests that the colour opponency system of the fish may regulate the response to selection.

  19. Evolution of colour vision in mammals

    PubMed Central

    Jacobs, Gerald H.

    2009-01-01

    Colour vision allows animals to reliably distinguish differences in the distributions of spectral energies reaching the eye. Although not universal, a capacity for colour vision is sufficiently widespread across the animal kingdom to provide prima facie evidence of its importance as a tool for analysing and interpreting the visual environment. The basic biological mechanisms on which vertebrate colour vision ultimately rests, the cone opsin genes and the photopigments they specify, are highly conserved. Within that constraint, however, the utilization of these basic elements varies in striking ways in that they appear, disappear and emerge in altered form during the course of evolution. These changes, along with other alterations in the visual system, have led to profound variations in the nature and salience of colour vision among the vertebrates. This article concerns the evolution of colour vision among the mammals, viewing that process in the context of relevant biological mechanisms, of variations in mammalian colour vision, and of the utility of colour vision. PMID:19720656

  20. Using students' misconceptions of primary coloured lights to design a hands-on coloured light mixer

    NASA Astrophysics Data System (ADS)

    Nopparatjamjomras, Suchai; Chitaree, Ratchapak

    2009-06-01

    A surface mount typed multi-coloured Light-Emitting Diode (LED) is used as a light source for the hands-on coloured light mixer. The LED consists of red, green and blue tiny sources but the mixer is designed to have four switches corresponding to red, green, blue and yellow light. These colours correspond to students' misconceptions of primary coloured lights; they realize that the primary colours and the rules for lights mixing are the same as those of paints. To generate a yellow light, a microcontroller placed between four input switches and the LED operates both a red and green tiny sources. In addition, the microcontroller is employed to eliminate some combinations of coloured light mixing to simplify the experiment (basic mode) for non advanced students. If the mixer is used with more advanced students, a number of combinations will increase and students need more analytical skills to find out the primary coloured lights (the coloured lights that can not be produced by the mixing of any other coloured lights). Therefore, the mixer is able to use with more advanced and non advanced students depending on the program in the microcontroller and some modifications of the circuit. Furthermore, to introduce students an idea that other hues or shades can be generated by mixing of these three primary coloured lights of different intensities, a tuning circuit is integrated to vary an intensity of the green light source.

  1. Most and Least Preferred Colours Differ According to Object Context: New Insights from an Unrestricted Colour Range.

    PubMed

    Jonauskaite, Domicele; Mohr, Christine; Antonietti, Jean-Philippe; Spiers, Peter M; Althaus, Betty; Anil, Selin; Dael, Nele

    2016-01-01

    Humans like some colours and dislike others, but which particular colours and why remains to be understood. Empirical studies on colour preferences generally targeted most preferred colours, but rarely least preferred (disliked) colours. In addition, findings are often based on general colour preferences leaving open the question whether results generalise to specific objects. Here, 88 participants selected the colours they preferred most and least for three context conditions (general, interior walls, t-shirt) using a high-precision colour picker. Participants also indicated whether they associated their colour choice to a valenced object or concept. The chosen colours varied widely between individuals and contexts and so did the reasons for their choices. Consistent patterns also emerged, as most preferred colours in general were more chromatic, while for walls they were lighter and for t-shirts they were darker and less chromatic compared to least preferred colours. This meant that general colour preferences could not explain object specific colour preferences. Measures of the selection process further revealed that, compared to most preferred colours, least preferred colours were chosen more quickly and were less often linked to valenced objects or concepts. The high intra- and inter-individual variability in this and previous reports furthers our understanding that colour preferences are determined by subjective experiences and that most and least preferred colours are not processed equally.

  2. Most and Least Preferred Colours Differ According to Object Context: New Insights from an Unrestricted Colour Range

    PubMed Central

    Jonauskaite, Domicele; Mohr, Christine; Antonietti, Jean-Philippe; Spiers, Peter M.; Althaus, Betty; Anil, Selin; Dael, Nele

    2016-01-01

    Humans like some colours and dislike others, but which particular colours and why remains to be understood. Empirical studies on colour preferences generally targeted most preferred colours, but rarely least preferred (disliked) colours. In addition, findings are often based on general colour preferences leaving open the question whether results generalise to specific objects. Here, 88 participants selected the colours they preferred most and least for three context conditions (general, interior walls, t-shirt) using a high-precision colour picker. Participants also indicated whether they associated their colour choice to a valenced object or concept. The chosen colours varied widely between individuals and contexts and so did the reasons for their choices. Consistent patterns also emerged, as most preferred colours in general were more chromatic, while for walls they were lighter and for t-shirts they were darker and less chromatic compared to least preferred colours. This meant that general colour preferences could not explain object specific colour preferences. Measures of the selection process further revealed that, compared to most preferred colours, least preferred colours were chosen more quickly and were less often linked to valenced objects or concepts. The high intra- and inter-individual variability in this and previous reports furthers our understanding that colour preferences are determined by subjective experiences and that most and least preferred colours are not processed equally. PMID:27022909

  3. Impact imaging of aircraft composite structure based on a model-independent spatial-wavenumber filter.

    PubMed

    Qiu, Lei; Liu, Bin; Yuan, Shenfang; Su, Zhongqing

    2016-01-01

    The spatial-wavenumber filtering technique is an effective approach to distinguish the propagating direction and wave mode of Lamb wave in spatial-wavenumber domain. Therefore, it has been gradually studied for damage evaluation in recent years. But for on-line impact monitoring in practical application, the main problem is how to realize the spatial-wavenumber filtering of impact signal when the wavenumber of high spatial resolution cannot be measured or the accurate wavenumber curve cannot be modeled. In this paper, a new model-independent spatial-wavenumber filter based impact imaging method is proposed. In this method, a 2D cross-shaped array constructed by two linear piezoelectric (PZT) sensor arrays is used to acquire impact signal on-line. The continuous complex Shannon wavelet transform is adopted to extract the frequency narrowband signals from the frequency wideband impact response signals of the PZT sensors. A model-independent spatial-wavenumber filter is designed based on the spatial-wavenumber filtering technique. Based on the designed filter, a wavenumber searching and best match mechanism is proposed to implement the spatial-wavenumber filtering of the frequency narrowband signals without modeling, which can be used to obtain a wavenumber-time image of the impact relative to a linear PZT sensor array. By using the two wavenumber-time images of the 2D cross-shaped array, the impact direction can be estimated without blind angle. The impact distance relative to the 2D cross-shaped array can be calculated by using the difference of time-of-flight between the frequency narrowband signals of two different central frequencies and the corresponding group velocities. The validations performed on a carbon fiber composite laminate plate and an aircraft composite oil tank show a good impact localization accuracy of the model-independent spatial-wavenumber filter based impact imaging method.

  4. Impact imaging of aircraft composite structure based on a model-independent spatial-wavenumber filter.

    PubMed

    Qiu, Lei; Liu, Bin; Yuan, Shenfang; Su, Zhongqing

    2016-01-01

    The spatial-wavenumber filtering technique is an effective approach to distinguish the propagating direction and wave mode of Lamb wave in spatial-wavenumber domain. Therefore, it has been gradually studied for damage evaluation in recent years. But for on-line impact monitoring in practical application, the main problem is how to realize the spatial-wavenumber filtering of impact signal when the wavenumber of high spatial resolution cannot be measured or the accurate wavenumber curve cannot be modeled. In this paper, a new model-independent spatial-wavenumber filter based impact imaging method is proposed. In this method, a 2D cross-shaped array constructed by two linear piezoelectric (PZT) sensor arrays is used to acquire impact signal on-line. The continuous complex Shannon wavelet transform is adopted to extract the frequency narrowband signals from the frequency wideband impact response signals of the PZT sensors. A model-independent spatial-wavenumber filter is designed based on the spatial-wavenumber filtering technique. Based on the designed filter, a wavenumber searching and best match mechanism is proposed to implement the spatial-wavenumber filtering of the frequency narrowband signals without modeling, which can be used to obtain a wavenumber-time image of the impact relative to a linear PZT sensor array. By using the two wavenumber-time images of the 2D cross-shaped array, the impact direction can be estimated without blind angle. The impact distance relative to the 2D cross-shaped array can be calculated by using the difference of time-of-flight between the frequency narrowband signals of two different central frequencies and the corresponding group velocities. The validations performed on a carbon fiber composite laminate plate and an aircraft composite oil tank show a good impact localization accuracy of the model-independent spatial-wavenumber filter based impact imaging method. PMID:26253754

  5. An efficient DCT-based image compression system based on laplacian transparent composite model.

    PubMed

    Sun, Chang; Yang, En-Hui

    2015-03-01

    Recently, a new probability model dubbed the Laplacian transparent composite model (LPTCM) was developed for DCT coefficients, which could identify outlier coefficients in addition to providing superior modeling accuracy. In this paper, we aim at exploring its applications to image compression. To this end, we propose an efficient nonpredictive image compression system, where quantization (including both hard-decision quantization (HDQ) and soft-decision quantization (SDQ)) and entropy coding are completely redesigned based on the LPTCM. When tested over standard test images, the proposed system achieves overall coding results that are among the best and similar to those of H.264 or HEVC intra (predictive) coding, in terms of rate versus visual quality. On the other hand, in terms of rate versus objective quality, it significantly outperforms baseline JPEG by more than 4.3 dB in PSNR on average, with a moderate increase on complexity, and ECEB, the state-of-the-art nonpredictive image coding, by 0.75 dB when SDQ is OFF (i.e., HDQ case), with the same level of computational complexity, and by 1 dB when SDQ is ON, at the cost of slight increase in complexity. In comparison with H.264 intracoding, our system provides an overall 0.4-dB gain or so, with dramatically reduced computational complexity; in comparison with HEVC intracoding, it offers comparable coding performance in the high-rate region or for complicated images, but with only less than 5% of the HEVC intracoding complexity. In addition, our proposed system also offers multiresolution capability, which, together with its comparatively high coding efficiency and low complexity, makes it a good alternative for real-time image processing applications.

  6. Investigation of the composition of anabolic tablets using near infrared spectroscopy and Raman chemical imaging.

    PubMed

    Rebiere, Hervé; Ghyselinck, Céline; Lempereur, Laurent; Brenier, Charlotte

    2016-01-01

    The use of performance enhancing drugs is a widespread phenomenon in professional and leisure sports. A spectroscopic study was carried out on anabolic tablets labelled as 5 mg methandienone tablets provided by police departments. The analytical approach was based on a two-step methodology: a fast analysis of tablets using near infrared (NIR) spectroscopy to assess sample homogeneity based on their global composition, followed by Raman chemical imaging of one sample per NIR profile to obtain information on sample formulation. NIR spectroscopy assisted by a principal components analysis (PCA) enabled fast discrimination of different profiles based on the excipient formulation. Raman hyperspectral imaging and multivariate curve resolution - alternating least square (MCR-ALS) provided chemical images of the distribution of the active substance and excipients within tablets and facilitated identification of the active compounds. The combination of NIR spectroscopy and Raman chemical imaging highlighted dose-to-dose variations and succeeded in the discrimination of four different formulations out of eight similar samples of anabolic tablets. Some samples contained either methandienone or methyltestosterone whereas one sample did not contain an active substance. Other ingredients were sucrose, lactose, starch or talc. Both techniques were fast and non-destructive and therefore can be carried out as exploratory methods prior to destructive screening methods. Copyright © 2015 John Wiley & Sons, Ltd.

  7. Development of in-situ imaging tools to quantify vegetation stress, plant mortality, and species composition

    NASA Astrophysics Data System (ADS)

    Goulden, M.

    2014-12-01

    We have developed and deployed an imaging system at an eddy covariance site in a Southern California Pinyon-Juniper woodland; our goals are to quantify the species-level patterns of stress and mortality over time, and also to learn how to better interpret the Landsat record. Our imaging system combines a four channel spectrometer with cameras that are sensitive to Visible, Near Infrared (NIR), Shortwave Infrared (SWIR), and Thermal radiation; these cameras include filters that mimic the spectral sensitivity of several Landsat bands. The cameras and spectrometer foreoptic are positioned on a pan-tilt mount on the tower that scans a 300o x 90o area every hour and allows us to collect images of hundreds of distinct plants. The imaging system is being used to test several approaches that have been proposed to detect vegetation stress, mortality, and species composition. We are exploring the potential to detect stomatal closure and stress by: a) increased canopy temperature with decreased evaporative cooling, b) Photochemical Reflectance Index (PRI), c) Fraunhofer line fluorescence, and d) water band indices. Similarly, we are exploring the potential to detect plant mortality by: a) NIR reflectance, b) SWIR reflectance, and c) radiance temperature with soil exposure, and to identify plant species by: a) differential phenological and interannual patterns, b) spectral reflectance, and c) BRDF and the effect of solar angle.

  8. Individual colour patches as multicomponent signals.

    PubMed

    Grether, Gregory F; Kolluru, Gita R; Nersissian, Karen

    2004-08-01

    Colour patches are complex traits, the components of which may evolve independently through a variety of mechanisms. Although usually treated as simple, two-dimensional characters and classified as either structural or pigmentary, in reality colour patches are complicated, three-dimensional structures that often contain multiple pigment types and structural features. The basic dermal chromatophore unit of fishes, reptiles and amphibians consists of three contiguous cell layers. Xanthophores and erythrophores in the outermost layer contain carotenoid and pteridine pigments that absorb short-wave light; iridophores in the middle layer contain crystalline platelets that reflect light back through the xanthophores; and melanophores in the basal layer contain melanins that absorb light across the spectrum. Changes in any one component of a chromatophore unit can drastically alter the reflectance spectrum produced, and for any given adaptive outcome (e.g. an increase in visibility), there may be multiple biochemical or cellular routes that evolution could take, allowing for divergent responses by different populations or species to similar selection regimes. All of the mechanisms of signal evolution that previously have been applied to single ornaments (including whole colour patches) could potentially be applied to the individual components of colour patches. To reach a complete understanding of colour patch evolution, however, it may be necessary to take an explicitly multi-trait approach. Here, we review multiple trait evolution theory and the basic mechanisms of colour production in fishes, reptiles and amphibians, and use a combination of computer simulations and empirical examples to show how multiple trait evolution theory can be applied to the components of single colour patches. This integrative perspective on animal colouration opens up a host of new questions and hypotheses. We offer specific, testable functional hypotheses for the most common pigmentary

  9. Application of Image And X-Ray Microtomography Technique To Quantify Filler Distribution In Thermoplastic-Natural Rubber Blend Composites

    SciTech Connect

    Ahmad, Sahrim; Rasid, Rozaidi; Mouad, A. T.; Aziz Mohamed, A.; Abdullah, Jaafar; Dahlan, M.; Mohamad, Mahathir; Jamro, Rafhayudi; Hamzah Harun, M.; Yazid, Hafizal; Abdullah, W. Saffiey W.

    2010-01-05

    X-ray microtomography and ImageJ 1.39 u is used as a tool to quantify volume percentage of B{sub 4}C as fillers in thermoplastic-natural rubber blend composites. The use of percentage of area occupied by fillers as obtain from ImageJ from the microtomography sliced images enables the proposed technique to easily obtain the amount volume percentage of B{sub 4}C in the composite non-destructively. Comparison with other technique such as density measurement and chemical analysis proves the proposed technique as one of the promising approach.

  10. Paths to colour in the retina.

    PubMed

    Lee, Barry B

    2004-07-01

    The description of colour pathways in the primate retina has become clearer within the past decade. This review summarises current views on the pathways subserving colour vision in the primate retina, beginning in the receptors and outer retina and leading to the mechanisms in the inner retina that add and subtract the receptor signals. Although the main features of colour pathways are now well-defined, there remains uncertainty about some of the wiring details. In particular, the question of how much connectional specificity is present is unresolved. Finally, means of isolating these pathways by psychophysical tests are considered; some current tests are likely to be less specific than hoped.

  11. Drug-induced hair colour changes.

    PubMed

    Bublin, J G; Thompson, D F

    1992-10-01

    Drug-induced hair colour changes are not a common adverse effect from medications. A wide variety of drugs have been implicated in causing hair colour changes but very few have data to support a true relationship. Of the drugs reported, chloroquine and cancer chemotherapeutic agents have the best evidence to support an association. Other drugs, such as p-aminobenzoic acid, calcium pantothenate, anthralin, chinoform, mephenesin, minoxidil, propofol, valproic acid, and verapamil await confirmatory data. Drug-induced causes should be considered in any patient with unexplained hair colour changes. PMID:1464633

  12. Natural ingredients for colouring and styling.

    PubMed

    Dweck, A C

    2002-10-01

    This paper examines some of the existing methods for colouring the hair and skin using natural material (such as henna) and proposes a parallel technology that exists in the dyeing of wool and fabrics to extend the colour range. Many of the listed plants and their derivatives are not found in Annex IV of the Cosmetic Directive and may not be used as colours; however, they do have other properties which may justify their inclusion into a product, for example, as astringent or anti-inflammatory agents. The paper concludes with some reported antigreying and hair styling preparations cited in the literature.

  13. Shrinkage of dental composite in simulated cavity measured with digital image correlation.

    PubMed

    Li, Jianying; Thakur, Preetanjali; Fok, Alex S L

    2014-07-21

    Polymerization shrinkage of dental resin composites can lead to restoration debonding or cracked tooth tissues in composite-restored teeth. In order to understand where and how shrinkage strain and stress develop in such restored teeth, Digital Image Correlation (DIC) was used to provide a comprehensive view of the displacement and strain distributions within model restorations that had undergone polymerization shrinkage. Specimens with model cavities were made of cylindrical glass rods with both diameter and length being 10 mm. The dimensions of the mesial-occlusal-distal (MOD) cavity prepared in each specimen measured 3 mm and 2 mm in width and depth, respectively. After filling the cavity with resin composite, the surface under observation was sprayed with first a thin layer of white paint and then fine black charcoal powder to create high-contrast speckles. Pictures of that surface were then taken before curing and 5 min after. Finally, the two pictures were correlated using DIC software to calculate the displacement and strain distributions. The resin composite shrunk vertically towards the bottom of the cavity, with the top center portion of the restoration having the largest downward displacement. At the same time, it shrunk horizontally towards its vertical midline. Shrinkage of the composite stretched the material in the vicinity of the "tooth-restoration" interface, resulting in cuspal deflections and high tensile strains around the restoration. Material close to the cavity walls or floor had direct strains mostly in the directions perpendicular to the interfaces. Summation of the two direct strain components showed a relatively uniform distribution around the restoration and its magnitude equaled approximately to the volumetric shrinkage strain of the material.

  14. Shrinkage of dental composite in simulated cavity measured with digital image correlation.

    PubMed

    Li, Jianying; Thakur, Preetanjali; Fok, Alex S L

    2014-01-01

    Polymerization shrinkage of dental resin composites can lead to restoration debonding or cracked tooth tissues in composite-restored teeth. In order to understand where and how shrinkage strain and stress develop in such restored teeth, Digital Image Correlation (DIC) was used to provide a comprehensive view of the displacement and strain distributions within model restorations that had undergone polymerization shrinkage. Specimens with model cavities were made of cylindrical glass rods with both diameter and length being 10 mm. The dimensions of the mesial-occlusal-distal (MOD) cavity prepared in each specimen measured 3 mm and 2 mm in width and depth, respectively. After filling the cavity with resin composite, the surface under observation was sprayed with first a thin layer of white paint and then fine black charcoal powder to create high-contrast speckles. Pictures of that surface were then taken before curing and 5 min after. Finally, the two pictures were correlated using DIC software to calculate the displacement and strain distributions. The resin composite shrunk vertically towards the bottom of the cavity, with the top center portion of the restoration having the largest downward displacement. At the same time, it shrunk horizontally towards its vertical midline. Shrinkage of the composite stretched the material in the vicinity of the "tooth-restoration" interface, resulting in cuspal deflections and high tensile strains around the restoration. Material close to the cavity walls or floor had direct strains mostly in the directions perpendicular to the interfaces. Summation of the two direct strain components showed a relatively uniform distribution around the restoration and its magnitude equaled approximately to the volumetric shrinkage strain of the material. PMID:25079865

  15. Shrinkage of Dental Composite in Simulated Cavity Measured with Digital Image Correlation

    PubMed Central

    Li, Jianying; Thakur, Preetanjali; Fok, Alex S. L.

    2014-01-01

    Polymerization shrinkage of dental resin composites can lead to restoration debonding or cracked tooth tissues in composite-restored teeth. In order to understand where and how shrinkage strain and stress develop in such restored teeth, Digital Image Correlation (DIC) was used to provide a comprehensive view of the displacement and strain distributions within model restorations that had undergone polymerization shrinkage. Specimens with model cavities were made of cylindrical glass rods with both diameter and length being 10 mm. The dimensions of the mesial-occlusal-distal (MOD) cavity prepared in each specimen measured 3 mm and 2 mm in width and depth, respectively. After filling the cavity with resin composite, the surface under observation was sprayed with first a thin layer of white paint and then fine black charcoal powder to create high-contrast speckles. Pictures of that surface were then taken before curing and 5 min after. Finally, the two pictures were correlated using DIC software to calculate the displacement and strain distributions. The resin composite shrunk vertically towards the bottom of the cavity, with the top center portion of the restoration having the largest downward displacement. At the same time, it shrunk horizontally towards its vertical midline. Shrinkage of the composite stretched the material in the vicinity of the “tooth-restoration” interface, resulting in cuspal deflections and high tensile strains around the restoration. Material close to the cavity walls or floor had direct strains mostly in the directions perpendicular to the interfaces. Summation of the two direct strain components showed a relatively uniform distribution around the restoration and its magnitude equaled approximately to the volumetric shrinkage strain of the material. PMID:25079865

  16. High dynamic range optical scanning of sediments and rock samples: More than colour?

    NASA Astrophysics Data System (ADS)

    Klug, Martin; Fabian, Karl; Knies, Jochen

    2015-04-01

    An automated high dynamic range (HDR) scanning procedure for cores and single sediment samples has been developed based on the GeoTek core scanner equipped with a 3* 2048 pixel CCD array GeoScan colour line-scan camera and a Sigma AF 105mm F2.8 EX DG MACRO lens. Repeated colour line scans of the same core sequence using different illumination and exposure time settings, but equal aperture, can be combined into single HDR images. This yields improved colour definition especially if layers of highly variable brightness occur in the same sequence. Colour calibration is performed automatically during image processing based on synchronization of colour charts. Polarized light is used to minimize gloss on wet surfaces. Beyond improved colour detection, high resolution scans with pixel size down to 25 µm provide the possibility of quantifying fabric, texture, and colour contrast between mottle and matrix. We present examples from marine sediments, lake sediments, hard rock cores, and individual soil samples. Due to the high resolution in sediment sequences, the improved images provide important background information to interpret synchronous measurements of density, magnetic susceptibility, or X-ray fluorescence with respect to their respective measurement footprint. If for example an XRF measurement indicates a 2% increase in Fe at a location of a thin black layer of 1/10 of the XRF measurement footprint, within an otherwise homogenous sequence, it can be inferred that the real Fe abundance within the layer is probably 20% higher than in the surrounding sediment. HDR scanning can therefore help to provide high resolution informed interpolation and deconvolution of measurements with larger sensor footprints.

  17. Pollinator responses to floral colour change, nectar, and scent promote reproductive fitness in Quisqualis indica (Combretaceae)

    PubMed Central

    Yan, Juan; Wang, Gang; Sui, Yi; Wang, Menglin; Zhang, Ling

    2016-01-01

    Floral colour change is visual signals for pollinators to avoid old flowers and increase pollination efficiency. Quisqualis indica flowers change colour from white to pink to red may be associated with a shift from moth to butterfly pollination. To test this hypothesis, we investigated Q. indica populations in Southwest China. Flowers secreted nectar continuously from the evening of anthesis until the following morning, then decreased gradually with floral colour change. The scent compounds in the three floral colour stages were similar; however, the scent composition was different, and the scent emission rate decreased from the white to red stage. Dichogamy in Q. indica prevents self-pollination and interference of male and female functions. Controlled pollinations demonstrated that this species is self-incompatible and needs pollinators for seed production. Different pollinators were attracted in each floral colour stage; mainly moths at night and bees and butterflies during the day. Observations of open-pollinated inflorescences showed that white flowers had a higher fruit set than pink or red flowers, indicating the high contribution of moths to reproductive success. We concluded that the nectar and scent secretion are related to floral colour change in Q. indica, in order to attract different pollinators and promote reproductive fitness. PMID:27072926

  18. Genetic engineering of novel flower colour by suppression of anthocyanin modification genes in gentian.

    PubMed

    Nakatsuka, Takashi; Mishiba, Kei-ichiro; Kubota, Akiko; Abe, Yoshiko; Yamamura, Saburo; Nakamura, Noriko; Tanaka, Yoshikazu; Nishihara, Masahiro

    2010-02-15

    Ornamental gentian plants have vivid-blue flowers. The main factor contributing to the flower colour is the accumulation of a polyacylated delphinidin 'gentiodelphin' in their petals. Although in vitro studies proposed that acylation plays an important role in the stability and development of gentian blue colour, the in vivo stability of the polyacylated anthocyanin was not clearly demonstrated. Thus, to reveal the importance of anthocyanin modification, especially acylation, and to engineer new colours of gentian flowers, we used chimeric RNAi technology to produce transgenic gentian plants with downregulated anthocyanin 5,3'-aromatic acyltransferase (5/3'AT) and flavonoid 3',5'-hydroxylase (F3'5'H) activities, which are both essential enzymes for gentiodelphin biosynthesis. Two lines of flower colour-modified plants were obtained from fifteen transgenic gentian plants. Clone no. 1 exhibited a lilac flower colour and clone no. 15 exhibited pale-blue flowers. RNA gel blot analysis confirmed that both transgenic lines had markedly suppressed 5/3'AT transcripts, whereas clone no. 15 had fewer F3'5'H transcripts than clone no. 1 and untransformed control plants. HPLC analysis of anthocyanin compositions showed that downregulation of the 5/3'AT gene led to increased accumulation of non-acylated anthocyanins, as expected. These results demonstrated that genetic engineering to reduce the accumulation of polyacylated anthocyanins could cause modulations of flower colour.

  19. Pollinator responses to floral colour change, nectar, and scent promote reproductive fitness in Quisqualis indica (Combretaceae).

    PubMed

    Yan, Juan; Wang, Gang; Sui, Yi; Wang, Menglin; Zhang, Ling

    2016-01-01

    Floral colour change is visual signals for pollinators to avoid old flowers and increase pollination efficiency. Quisqualis indica flowers change colour from white to pink to red may be associated with a shift from moth to butterfly pollination. To test this hypothesis, we investigated Q. indica populations in Southwest China. Flowers secreted nectar continuously from the evening of anthesis until the following morning, then decreased gradually with floral colour change. The scent compounds in the three floral colour stages were similar; however, the scent composition was different, and the scent emission rate decreased from the white to red stage. Dichogamy in Q. indica prevents self-pollination and interference of male and female functions. Controlled pollinations demonstrated that this species is self-incompatible and needs pollinators for seed production. Different pollinators were attracted in each floral colour stage; mainly moths at night and bees and butterflies during the day. Observations of open-pollinated inflorescences showed that white flowers had a higher fruit set than pink or red flowers, indicating the high contribution of moths to reproductive success. We concluded that the nectar and scent secretion are related to floral colour change in Q. indica, in order to attract different pollinators and promote reproductive fitness. PMID:27072926

  20. Multi-contrast 3D X-ray imaging of porous and composite materials

    SciTech Connect

    Sarapata, Adrian; Herzen, Julia; Ruiz-Yaniz, Maite; Zanette, Irene; Rack, Alexander; Pfeiffer, Franz

    2015-04-13

    Grating-based X-ray computed tomography allows for simultaneous and nondestructive determination of the full X-ray complex index of refraction and the scattering coefficient distribution inside an object in three dimensions. Its multi-contrast capabilities combined with a high resolution of a few micrometers make it a suitable tool for assessing multiple phases inside porous and composite materials such as concrete. Here, we present quantitative results of a proof-of-principle experiment performed on a concrete sample. Thanks to the complementarity of the contrast channels, more concrete phases could be distinguished than in conventional attenuation-based imaging. The phase-contrast reconstruction shows high contrast between the hardened cement paste and the aggregates and thus allows easy 3D segmentation. Thanks to the dark-field image, micro-cracks inside the coarse aggregates are visible. We believe that these results are extremely interesting in the field of porous and composite materials studies because of unique information provided by grating interferometry in a non-destructive way.

  1. Studying Interstellar Dust Grain Composition with X-ray Spectroscopic Imaging

    NASA Astrophysics Data System (ADS)

    Corrales, Lia; Garcia, Javier; Smith, Randall; Wilms, Joern; Schulz, Norbert; Nowak, Mike; Baganoff, Frederick

    2015-10-01

    Interstellar dust in the foreground of bright point sources will scatter X-rays over arcminute scales, producing a diffuse halo image. The scattering halo intensity is strongly sensitive to the dust grain size distribution, spatial distribution, and composition of dust on the sight line. Currently, Chandra's spatial resolution makes it the best detector available for studying X-ray scattering halos from the diffuse ISM. A Chandra successor with similar resolution but larger effective area will lend a greater opportunity to study scattering echoes from low column densities of the diffuse interstellar or intergalactic medium. More importantly, the combination of high resolution spectroscopy with imaging is uniquely suited to studying the composition of dust grains. At soft energies in particular, the spectrum of scattered light is likely to have significant features at the 0.3 keV C-K and 0.5 O-K photoelectric absorption edges. This direct probe of ISM dust grain elements will be important for i understanding the relative abundances of graphitic grains or PAHs versus silicates, and ii measuring the depletion of gas phase elements into solid form.

  2. Why colour in subterranean vertebrates? Exploring the evolution of colour patterns in caecilian amphibians.

    PubMed

    Wollenberg, K C; Measey, C John

    2009-05-01

    The proximate functions of animal skin colour are difficult to assign as they can result from natural selection, sexual selection or neutral evolution under genetic drift. Most often colour patterns are thought to signal visual stimuli; so,their presence in subterranean taxa is perplexing. We evaluate the adaptive nature of colour patterns in nearly a third of all known species of caecilians, an order of amphibians most of which live in tropical soils and leaf litter. We found that certain colour pattern elements in caecilians can be explained based on characteristics concerning above-ground movement. Our study implies that certain caecilian colour patterns have convergently evolved under selection and we hypothesize their function most likely to be a synergy of aposematism and crypsis, related to periods when individuals move overground. In a wider context, our results suggest that very little exposure to daylight is required to evolve and maintain a varied array of colour patterns in animal skin.

  3. Why colour in subterranean vertebrates? Exploring the evolution of colour patterns in caecilian amphibians.

    PubMed

    Wollenberg, K C; Measey, C John

    2009-05-01

    The proximate functions of animal skin colour are difficult to assign as they can result from natural selection, sexual selection or neutral evolution under genetic drift. Most often colour patterns are thought to signal visual stimuli; so,their presence in subterranean taxa is perplexing. We evaluate the adaptive nature of colour patterns in nearly a third of all known species of caecilians, an order of amphibians most of which live in tropical soils and leaf litter. We found that certain colour pattern elements in caecilians can be explained based on characteristics concerning above-ground movement. Our study implies that certain caecilian colour patterns have convergently evolved under selection and we hypothesize their function most likely to be a synergy of aposematism and crypsis, related to periods when individuals move overground. In a wider context, our results suggest that very little exposure to daylight is required to evolve and maintain a varied array of colour patterns in animal skin. PMID:21462404

  4. Colour vision: parallel pathways intersect in Drosophila.

    PubMed

    Kelber, Almut; Henze, Miriam J

    2013-12-01

    In the last one hundred years, colour vision has been demonstrated in bees and many other insects. But the underlying neural wiring remained elusive. A new study on Drosophila melanogaster combining behavioural and genetic tools yields surprising insights. PMID:24309280

  5. Edges, colour and awareness in blindsight.

    PubMed

    Alexander, Iona; Cowey, Alan

    2010-06-01

    It remains unclear what is being processed in blindsight in response to faces, colours, shapes, and patterns. This was investigated in two hemianopes with chromatic and achromatic stimuli with sharp or shallow luminance or chromatic contrast boundaries or temporal onsets. Performance was excellent only when stimuli had sharp spatial boundaries. When discrimination between isoluminant coloured Gaussians was good it declined to chance levels if stimulus onset was slow. The ability to discriminate between instantaneously presented colours in the hemianopic field depended on their luminance, indicating that wavelength discrimination totally independent of other stimulus qualities is absent. When presented with narrow-band colours the hemianopes detected a stimulus maximally effective for S-cones but invisible to M- and L-cones, indicating that blindsight is mediated not just by the mid-brain, which receives no S-cone input, or that the rods contribute to blindsight. The results show that only simple stimulus features are processed in blindsight.

  6. Fracture behavior of reinforced aluminum alloy matrix composites using thermal imaging tools

    NASA Astrophysics Data System (ADS)

    Avdelidis, N. P.; Exarchos, D.; Vazquez, P.; Ibarra-Castanedo, C.; Sfarra, S.; Maldague, X. P. V.; Matikas, T. E.

    2016-05-01

    In this work the influence of the microstructure at the vicinity of the interface on the fracture behavior of particulate-reinforced aluminum alloy matrix composites (Al/SiCp composites) is studied by using thermographic tools. In particular, infrared thermography was used to monitor the plane crack propagation behavior of the materials. The deformation of solid materials is almost always accompanied by heat release. When the material becomes deformed or is damaged and fractured, a part of the energy necessary to initiate and propagate the damage is transformed in an irreversible way into heat. The thermal camera detects the heat wave, generated by the thermo-mechanical coupling and the intrinsic dissipated energy during mechanical loading of the sample. By using an adapted detector, thermography records the two dimensional "temperature" field as it results from the infrared radiation emitted by the object. The principal advantage of infrared thermography is its noncontact, non-destructive character. This methodology is being applied to characterise the fracture behavior of the particulate composites. Infrared thermography is being used to monitor the plane crack propagation behavior of such materials. Furthermore, an innovative approach to use microscopic measurements using IR microscopic lenses was attempted, in order to enable smaller features (in the micro scale) to be imaged with accuracy and assurance.

  7. Micro-measurements of mechanical properties for adhesives and composites using digital imaging technology

    NASA Technical Reports Server (NTRS)

    Brinson, Hal F.

    1994-01-01

    The need for a constituent based durability or accelerated life prediction procedure to be used for the engineering design of polymer matrix composites is discussed in the light of current plans for the High Speed Civil Transport (HSCT) concerns about the U.S. infrastructure (bridges, pipelines, etc.) and other technological considerations of national concern. It is pointed out that good measurement procedures for insitu resin properties are needed for both adhesives and composites. A double cantilever beam (DCB) specimen which shows promise for the easy determination of adhesive shear properties is presented and compared with measurements of strains within the bondline using a new optical digital imaging micro-measurement system (DIMMS). The DCB specimen is also used to assess damage in a bonded joint using a dynamic mechanical thermal analysis system (DMTA). The possible utilization of the same DIMMS and DMTA procedures to determine the insitu properties of the resin in a composite specimen are discussed as well as the use of the procedures to evaluate long term mechanical and physical aging. Finally, a discussion on the state-of-the art of the measurement of strains in micron and sub-micron domains is given.

  8. A new test phantom with different breast tissue compositions for image quality assessment in conventional and digital mammography

    NASA Astrophysics Data System (ADS)

    Pachoud, Marc; Lepori, D.; Valley, Jean-François; Verdun, Francis R.

    2004-12-01

    Our objective is to describe a new test phantom that permits the objective assessment of image quality in conventional and digital mammography for different types of breast tissue. A test phantom, designed to represent a compressed breast, was made from tissue equivalent materials. Three separate regions, with different breast tissue compositions, are used to evaluate low and high contrast resolution, spatial resolution and image noise. The phantom was imaged over a range of kV using a Contour 2000 (Bennett) mammography unit with a Kodak MinR 2190-MinR L screen film combination and a Senograph 2000D (General Electric) digital mammography unit. Objective image quality assessments for different breast tissue compositions were performed using the phantom for conventional and digital mammography. For a similar mean glandular dose (MGD), the digital system gives a significantly higher contrast-to-noise ratio (CNR) than the screen film system for 100% glandular tissue. In conclusion, in mammography, a range of exposure conditions is used for imaging because of the different breast tissue compositions encountered clinically. Ideally, the patient dose image quality relationship should be optimized over the range of exposure conditions. The test phantom presented in this work permits image quality parameters to be evaluated objectively for three different types of breast tissue. Thus, it is a useful tool for optimizing the patient dose image quality relationship.

  9. Interaction of Gender and Body Composition on Rectus Femoris Morphology as Measured With Musculoskeletal Ultrasound Imaging

    PubMed Central

    Martinez, Corina; Davis, Ashley; Myers, Heather; Butler, Robert J.

    2014-01-01

    Background: Quadriceps function is an important measure in patients recovering postoperatively. Traditionally, strength measures that require high levels of resistance are contraindicated during the early postoperative phase. Thus it may be helpful to evaluate the utilization of other tools, such as ultrasound imaging, that allow for assessment during a position of low resistance. Hypothesis: The rectus femoris cross-sectional area (CSA) is affected by sex and body composition in healthy subjects. Study Design: Cross-sectional study. Level of Evidence: Level 4. Methods: Thirty-two healthy subjects (16 women, 16 men), selected from a previously larger study, were chosen for analysis. All subjects underwent a maximal volitional isometric contraction protocol from 0° to 90° of knee motion controlled by an isokinetic dynamometer. In the contracted and resting positions, the rectus femoris CSA was measured at each angle using ultrasound imaging. The contractile index (contracted − resting CSA) was calculated at each position. Subjects were separated into 1 of 4 groups based on sex and fat percentage (low or high). These data were analyzed using mixed-factor analysis of variance (group × angle) for each variable, with a critical α level of 0.05. Results: A significant interaction was noted for the CSA of the rectus femoris at rest (P < 0.03) and during contraction (P < 0.02). For both variables, all groups performed similarly, with the exception of women with high body fat percentage. No statistically significant interaction existed for the contractile index; however, a main effect for angle (P < 0.01) was observed. Conclusion: Rectus femoris CSA appears to depend on sex as well as the body composition of individuals. Clinical Relevance: Traditional subjective assessment measures of quadriceps strength and function have low reliability and functional validity. With the improved feasibility of ultrasound imaging in the clinical setting, quadriceps size may be more

  10. Determining thermal diffusivity and defect attributes in ceramic matrix composites by infrared imaging.

    SciTech Connect

    Ahuja, S.; Ellingson, W. A.; Koehl, E. R.; Stuckey, J.

    1997-12-05

    Ceramic matrix composites are being developed for numerous high temperature applications, including rotors and combustors for advanced turbine engines, heat exchanger and hot-gas filters for coal gasification plants. Among the materials of interest are silicon-carbide-fiber-reinforced-silicon-carbide (SiC{sub (f)}/SiC), silicon-carbide-fiber-reinforced-silicon-nitride (SiC{sub (f)}/Si{sub 3}N{sub 4}), aluminum-oxide-reinforced-alumina (Al{sub 2}O{sub 3(f)}/Al{sub 2}O{sub 3}), etc. In the manufacturing of these ceramic composites, the conditions of the fiber/matrix interface are critical to the mechanical and thermal behavior of the component. Defects such as delaminations and non-uniform porosity can directly effect the performance. A nondestructive evaluation (NDE) method, developed at Argonne National Laboratory has proved beneficial in analyzing as-processed conditions and defect detection created during manufacturing. This NDE method uses infrared thermal imaging for fill-field quantitative measurement of the distribution of thermal diffusivity in large components. Intensity transform algorithms have been used for contrast enhancement of the output image. Nonuniformity correction and automatic gain control are used to dynamically optimize video contrast and brightness, providing additional resolution in the acquired images. Digital filtering, interpolation, and least-squares-estimation techniques have been incorporated for noise reduction and data acquisition. The Argonne NDE system has been utilized to determine thermal shock damage, density variations, and variations in fiber coating in a full array of test specimens.

  11. Prediction of lean and fat composition in swine carcasses from ham area measurements with image analysis.

    PubMed

    Jia, Jiancheng; Schinckel, Allan P; Forrest, John C; Chen, Way; Wagner, Jeffrey R

    2010-06-01

    Video images of ham cross-sections were recorded from 71 pork carcasses (ranging in weight from 72 to 119kg). Three sets of prediction equations were developed to estimate pork carcass lean and fat composition from video image analysis (VIA) of ham cross-sectional area measurements, 10th rib back fat depth (TENFAT) and hot carcass weight (HCKg). Carcass data of dissected lean and fat in the four primal cuts (ham, loin, Boston button and picnic shoulder) were used as dependent variables in establishing regression equations. The first set of equations combined VIA ham measurements and total ham weight (HTKg). Regression models containing the single variable HTKg times ham percentage lean area (Vol. 1) or HTKg times ham percentage fat area (Vol. 2) accounted for 88% and 68% of the variation in total carcass lean weight (CLKg) and total carcass fat weight (CFKg) from the right side of each carcass, respectively. The second set of equations combined VIA ham measurements and TENFAT (cm). Multiple regression models involving TENFAT, Vol. 1, and Vol. 2 accounted for 91% and 90% of the variation in CLKg and CFKg. The third set of equations used VIA ham measurements, TENFAT and HCKg. Carcass lean weight was best predicted by HCKg, TENFAT, and ham lean area (HLA) (R(2)=.92). Carcass fat weight was best predicted by HCKg, TENFAT, and Vol. 2 (R(2)=.91). Overall correlations showed a high association between Vol. 1 and CLKg (r=.94, P<.0001) and Vol. 2 and CFKg (r=.83, P<.0001). Ham lean area was related to CLKg (r=.74, P<.0001) and ham fat area to CFKg (r=.81, P<.0001). The results of this study indicated video image analysis of ham cross-section slices combined with backfat depth at the 10th rib can be used for accurate estimation of total carcass lean or fat composition.

  12. MinMap: An imaging spectrometer for high resolution compositional mapping of the Moon

    NASA Technical Reports Server (NTRS)

    Pieters, C. M.; Head, James W.; Mccord, T. B.

    1993-01-01

    MinMap has been selected by the Lunar Scout program to characterize and map the mineral composition of the Moon. The instrument will be built as a collaborative effort between Brown University, SETS Technology Inc., and Ball Aerospace Corp. MinMap is a visible to near-infrared imaging spectrometer that contains 192 spectral channels from 0.35-2.4 microns with signal to noise greater than 200 and 256 cross-track spatial elements. The spectrometer design has a 6 deg field of view (FOV) and utilizes grating dispersive elements and two dimensional detectors (no moving parts). An 'image cube' of data is produced that contains two dimensions of spatial information and one dimension of spectral information. All spectral channels and cross-track spatial elements are recorded simultaneously with spacecraft motion scanning the second spatial dimension. The high spectral resolution and continuous spectral range of MinMap are designed to measure the diagnostic absorption features of principal lunar minerals and their lithologic mixtures. Since the optical properties of lunar materials change in a regular manner upon exposure to the space environment, this spectral range is also quite sensitive to variations in exposure history (soil maturity). Nominal measurement stragegy is to obtain full global data of the Moon at 180 m/pixel from a 450 km polar orbit during the first month or two of operation. A 100 km orbit is anticipated for the remaining part of a 1 year mission allowing higher resolution data (approx. 80 m/pixel) to be obtained for targeted regions. MinMap exceeds LE x SWG's measurement recommendations and will provide the highest spatial resolution compositional map of lunar rocks and soils currently planned for orbital missions. Since all spectral channels are co-registered and obtained simultaneously, 'image cube' data swaths will be available for analysis almost immediately.

  13. Understanding WCAG2.0 Colour Contrast Requirements Through 3D Colour Space Visualisation.

    PubMed

    Sandnes, Frode Eika

    2016-01-01

    Sufficient contrast between text and background is needed to achieve sufficient readability. WCAG2.0 provides a specific definition of sufficient contrast on the web. However, the definition is hard to understand and most designers thus use contrast calculators to validate their colour choices. Often, such checks are performed after design and this may be too late. This paper proposes a colour selection approach based on three-dimensional visualisation of the colour space. The complex non-linear relationships between the colour components become comprehendible when viewed in 3D. The method visualises the available colours in an intuitive manner and allows designers to check a colour against the set of other valid colours. Unlike the contrast calculators, the proposed method is proactive and fun to use. A colour space builder was developed and the resulting models were viewed with a point cloud viewer. The technique can be used as both a design tool and a pedagogical aid to teach colour theory and design. PMID:27534328

  14. Not so colourful after all: eggshell pigments constrain avian eggshell colour space.

    PubMed

    Hanley, Daniel; Grim, Tomáš; Cassey, Phillip; Hauber, Mark E

    2015-05-01

    Birds' eggshells are renowned for their striking colours and varied patterns. Although often considered exceptionally diverse, we report that avian eggshell coloration, sampled here across the full phylogenetic diversity of birds, occupies only 0.08-0.10% of the avian perceivable colour space. The concentrations of the two known tetrapyrrole eggshell pigments (protoporphyrin and biliverdin) are generally poor predictors of colour, both intra- and interspecifically. Here, we show that the constrained diversity of eggshell coloration can be accurately predicted by colour mixing models based on the relative contribution of both pigments and we demonstrate that the models' predictions can be improved by accounting for the reflectance of the eggshell's calcium carbonate matrix. The establishment of these proximate links between pigmentation and colour will enable future tests of hypotheses on the functions of perceived avian eggshell colours that depend on eggshell chemistry. More generally, colour mixing models are not limited to avian eggshell colours but apply to any natural colour. Our approach illustrates how modelling can aid the understanding of constraints on phenotypic diversity.

  15. Caramel colours--a historical introduction.

    PubMed

    Chappel, C I; Howell, J C

    1992-05-01

    Caramel colours used in the manufacture of a wide variety of foods and beverages have been an item of commerce for more than one hundred years. The regulatory history of these additives in the US, the UK, the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and the EC is reviewed, and an introduction to the safety studies of caramel colours in this issue of Food and Chemical Toxicology is provided. PMID:1644375

  16. Plants and colour: Flowers and pollination

    NASA Astrophysics Data System (ADS)

    Miller, Renee; Owens, Simon J.; Rørslett, Bjørn

    2011-03-01

    While there is a range of colours found in plants the predominant colour is green. Pigments in plants have several roles e.g. photosynthesis and signalling. If colour is to be used as a signal then it must stand out from green. However, one should be aware that there are also coloured compounds where we have not yet fully investigated the role of colour in their functions—they may have roles in, for example, defence or heat exchange. In this paper, we will describe the basic chemistry of the major pigments found in plants and especially floral pigments. We will then discuss their locations in parts of the flower (such as sepals, petals, pollen and nectar), the cells in which they are found and their sub-cellular locations. Floral pigments have a large role to play in pollination of flowers by animals. They can and are modified in many ways during the development of flowers in nature, for example, at emergence and post-pollination. There are a range of biochemical mechanisms of colour change both within flowers and in isolated pigments. Some of the factors influencing colour are temperature, co-pigments, pH, metals, sugars, anthocyanin stacking and cell shape. There is a renewed interest in analysing floral pigments and how they are modified partly because of advances in recombinant DNA technologies, but also because of pollinators and their significance to biodiversity and for evolutionary studies. There is continued strong interest from the horticultural industry for the introduction of new colours e.g. the blue rose and for the exploitation of natural dyes. Funding in this area may impact future research in a potentially beneficial way but it must not deflect us from science-based conservation.

  17. THE COLOUR GLASS CONDENSATE: AN INTRODUCTION

    SciTech Connect

    IANCU,E.; LEONIDOV,A.; MCLERRAN,L.

    2001-08-06

    In these lectures, the authors develop the theory of the Colour Glass Condensate. This is the matter made of gluons in the high density environment characteristic of deep inelastic scattering or hadron-hadron collisions at very high energy. The lectures are self contained and comprehensive. They start with a phenomenological introduction, develop the theory of classical gluon fields appropriate for the Colour Glass, and end with a derivation and discussion of the renormalization group equations which determine this effective theory.

  18. Colour preferences of juvenile turbot (Scophthalmus maximus).

    PubMed

    Li, Xian; Chi, Liang; Tian, Huiqin; Meng, Lingjie; Zheng, Jimeng; Gao, Xiaolong; Liu, Ying

    2016-03-15

    The background colour of aquaculture tanks is normally chosen based on practical experience and/or observations of fish behaviour and the growth rates achieved. However, some farmed species, including turbot, are sentient and can show a preference for a particular environment. In the current study, a self-referent colour preference device was developed and the self-referent colour preference of farmed fish investigated. In experiment 1, the background colour preference of juvenile turbot cultured under a grey background for >3months post-incubation was evaluated. Based on these results, in experiment 2, juvenile turbot were adapted to blue, pink, white, or black backgrounds for 50days and their preferences established. Meanwhile, the growth rates, feed intake, and metabolic rates (including oxygen consumption rate, and ammonia excretion rate) of the turbot were evaluated. The results showed that turbot farmed under a grey background, or after long-term white, blue, pink and black colour adaptation, always displayed a preference for a white background and a dislike for black, red, or brown backgrounds, although their body colour was greyish. Long-term adaptation influenced the frequency of juveniles selecting white, black, pink or blue backgrounds. They showed the highest growth rate, feed intake, and metabolic rates under blue and white backgrounds, and the lowest under a black backgrou