Science.gov

Sample records for color rendering index

  1. Semitransparent polymer solar cells with simultaneously improved efficiency and color rendering index.

    PubMed

    Yu, Wenjuan; Jia, Xu; Yao, Mengnan; Zhu, Linghui; Long, Yongbing; Shen, Liang

    2015-10-01

    Herein, we demonstrate a kind of high performance semi-transparent polymer solar cell (STPSC) with a significantly improved color rendering index (CRI) and power conversion efficiency (PCE) by introducing one-dimensional photonic crystals (1DPCs), which are intentionally designed to strongly reflect the pristine weak absorbed light to flatten the concavo-convex transmittance spectrum of STPSCs. The transmitted light from the STPSC device with 4 pairs of 1DPCs under AM 1.5G illumination shows extraordinary color rendering capacities, which contribute an increased CRI from 79 to 91, combined with an enhanced PCE from 4.14% to 5.01% compared to devices without 1DPCs. The simultaneously improved optical and electrical performance suggests that STPSCs can provide a unique feature, which is suitable for building integrated photovoltaic applications.

  2. Entropy, color, and color rendering.

    PubMed

    Price, Luke L A

    2012-12-01

    The Shannon entropy [Bell Syst. Tech J.27, 379 (1948)] of spectral distributions is applied to the problem of color rendering. With this novel approach, calculations for visual white entropy, spectral entropy, and color rendering are proposed, indices that are unreliant on the subjectivity inherent in reference spectra and color samples. The indices are tested against real lamp spectra, showing a simple and robust system for color rendering assessment. The discussion considers potential roles for white entropy in several areas of color theory and psychophysics and nonextensive entropy generalizations of the entropy indices in mathematical color spaces.

  3. High color rendering index white organic light-emitting diode using levofloxacin as blue emitter

    NASA Astrophysics Data System (ADS)

    Miao, Yan-Qin; Gao, Zhi-Xiang; Zhang, Ai-Qin; Li, Yuan-Hao; Wang, Hua; Jia, Hu-Sheng; Liu, Xu-Guang; Tsuboi, Taijuf

    2015-05-01

    Levofloxacin (LOFX), which is well-known as an antibiotic medicament, was shown to be useful as a 452-nm blue emitter for white organic light-emitting diodes (OLEDs). In this paper, the fabricated white OLED contains a 452-nm blue emitting layer (thickness of 30 nm) with 1 wt% LOFX doped in CBP (4,4’-bis(carbazol-9-yl)biphenyl) host and a 584-nm orange emitting layer (thickness of 10 nm) with 0.8 wt% DCJTB (4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidin-4-yl-vinyl)-4H-pyran) doped in CBP, which are separated by a 20-nm-thick buffer layer of TPBi (2,2’,2”-(benzene-1,3,5-triyl)-tri(1-phenyl-1H-benzimidazole). A high color rendering index (CRI) of 84.5 and CIE chromaticity coordinates of (0.33, 0.32), which is close to ideal white emission CIE (0.333, 0.333), are obtained at a bias voltage of 14 V. Taking into account that LOFX is less expensive and the synthesis and purification technologies of LOFX are mature, these results indicate that blue fluorescence emitting LOFX is useful for applications to white OLEDs although the maximum current efficiency and luminance are not high. The present paper is expected to become a milestone to using medical drug materials for OLEDs. Project supported by the Program for New Century Excellent Talents in University of Ministry of Education of China (Grant No. NCET-13-0927), the International Science & Technology Cooperation Program of China (Grant No. 2012DFR50460), the National Natural Science Foundation of China (Grant Nos. 21101111 and 61274056), and the Shanxi Provincial Key Innovative Research Team in Science and Technology, China (Grant No. 2012041011).

  4. [Optimizing Color Rendering for Mixed-Color White Light LED].

    PubMed

    Yu, Chun-yu; Jin, Peng; Zhou, Qi-feng

    2015-05-01

    To optimize color rendering of mixed-color LEDs, the Gaussian model was used to analyze the color-mixed LED's spectrum power distribution. The peak wavelength "λm", spectral half width "Δλ" and amplitude "A" were basic parameters for optimizing color rendering R9, which is very important for objects to be colorful and vivid under the white light LED's'illuminating. The typical methods for color mixing were used to get white light LEDs. Result was that to get the satisfied color rendering index, one of the color primaries should be certain and then other color primaries would be analyzed through changing three basic parameters step by step. It was concluded that the analysis in this paper would be referential to optimize the color-mixed white LED's color rendering. PMID:26415452

  5. [Optimizing Color Rendering for Mixed-Color White Light LED].

    PubMed

    Yu, Chun-yu; Jin, Peng; Zhou, Qi-feng

    2015-05-01

    To optimize color rendering of mixed-color LEDs, the Gaussian model was used to analyze the color-mixed LED's spectrum power distribution. The peak wavelength "λm", spectral half width "Δλ" and amplitude "A" were basic parameters for optimizing color rendering R9, which is very important for objects to be colorful and vivid under the white light LED's'illuminating. The typical methods for color mixing were used to get white light LEDs. Result was that to get the satisfied color rendering index, one of the color primaries should be certain and then other color primaries would be analyzed through changing three basic parameters step by step. It was concluded that the analysis in this paper would be referential to optimize the color-mixed white LED's color rendering.

  6. High Color-Rendering-index Hybrid White LEDs Employing CdSe/ZnS Core/Shell Quantum Dots.

    PubMed

    Chang, Yajing; Sun, Dapeng; Zhang, Zhongping; Zhang, Yugang; Yao, Xudong; Jiang, Danlu; Yu, Yalan; Mi, Longfei; Chen, Lei; Zhong, Honghai; Jiang, Yang

    2016-01-01

    Hybrid white LEDs were constructed by leveraging a combination of CdSe/ZnS core/shell QDs and YAG: Ce³⁺ phosphors. The CdSe/ZnS core/shell QDs were synthesized by a two-step process in which CdSe QDs were first prepared via a hot-injection method, followed by ZnS coating through a facile single-molecular precursor approach. The resultant red-emitting CdSe/ZnS QDs showed decent fluorescent quantum yielding (36%). The resultant hybrid white LEDs--that based on CdSe/ZnS QDs and solid-state-reaction-processed YAG: Ce³⁺ phosphors--showed good luminescence properties, including bright warm light, a high color rendering index of 91.3, a low color temperature of 4965 K and a luminous efficiency of 44.22 lm/W. Moreover, increased luminous intensity has been observed in the presence of increased forward current without luminescence saturation, promising an ideal approach to construct warm-white LEDs with excellent color rendering properties. PMID:27398506

  7. Highly efficient semitransparent polymer solar cells with color rendering index approaching 100 using one-dimensional photonic crystal.

    PubMed

    Yu, Wenjuan; Jia, Xu; Long, Yongbing; Shen, Liang; Liu, Yan; Guo, Wenbin; Ruan, Shengping

    2015-05-13

    Window application is the important aim for semitransparent solar cells (STPSC) investigation. Here, we demonstrate a method to achieve significantly improved color rendering index (CRI), depressed chromaticity difference (DC), and enhanced power conversion efficiency (PCE) simultaneously by introducing the one-dimensional photonic crystals (1DPCs) Bragg reflector structure onto the STPSC. The device performance is studied from aspects of color perception, electrical properties, and theoretical optical simulations. The STPSCs exhibit achromatic transparency nature color perceptions, especially for the STPSCs with 1DPCs (pairs ≥ 3) under AM 1.5G illumination light source, standard illuminant D65, and standard illuminant A. The excellent CRI is approaching 97 with lower DC about 0.0013 for the device with 5 pairs of 1DPC illumined by AM 1.5G illumination light source. At the same time, the PCE of STPSC devices with 5 pairs of 1DPC was improved from 4.87 ± 0.14% to 5.31 ± 0.13% compared to without. This method provides a facilitative approach to realizing excellent SPTSC window application.

  8. High color rendering index white light emitting diodes fabricated from a combination of carbon dots and zinc copper indium sulfide quantum dots

    NASA Astrophysics Data System (ADS)

    Sun, Chun; Zhang, Yu; Wang, Yu; Liu, Wenyan; Kalytchuk, Sergii; Kershaw, Stephen V.; Zhang, Tieqiang; Zhang, Xiaoyu; Zhao, Jun; Yu, William W.; Rogach, Andrey L.

    2014-06-01

    In a line with most recent trends in developing non-toxic fluorescent nanomaterials, we combined blue emissive carbon dots with green and red emissive zinc copper indium sulfide (ZCIS) core/shell quantum dots (QDs) to achieve white light-emitting diodes (WLEDs) with a high color rendering index of 93. This indicates that ZCIS QDs, with their broad emission bands, can be employed to effectively make up the emission of carbon dots in the yellow and red regions to produce WLEDs in the wide region of color temperature by tuning the volume ratio of these constituting luminophores. Their electroluminescence characteristics including color rendering index, Commission Internationale de l'Eclairage (CIE) color coordinates, and color temperatures were evaluated as a function of forward current. The CIE-1931 chromaticity coordinates of the as-prepared WLEDs, exhibiting good stability, were slightly shifted from (0.321, 0.312) at 10 mA to (0.351, 0.322) at 30 mA, which was mainly caused by the different thermal quenching coefficients of carbon dots and ZCIS QDs.

  9. High color rendering index white light emitting diodes fabricated from a combination of carbon dots and zinc copper indium sulfide quantum dots

    SciTech Connect

    Sun, Chun; Liu, Wenyan; Zhang, Xiaoyu; Zhang, Yu E-mail: wyu6000@gmail.com; Wang, Yu; Kalytchuk, Sergii; Kershaw, Stephen V.; Rogach, Andrey L.; Zhang, Tieqiang; Zhao, Jun; Yu, William W. E-mail: wyu6000@gmail.com

    2014-06-30

    In a line with most recent trends in developing non-toxic fluorescent nanomaterials, we combined blue emissive carbon dots with green and red emissive zinc copper indium sulfide (ZCIS) core/shell quantum dots (QDs) to achieve white light-emitting diodes (WLEDs) with a high color rendering index of 93. This indicates that ZCIS QDs, with their broad emission bands, can be employed to effectively make up the emission of carbon dots in the yellow and red regions to produce WLEDs in the wide region of color temperature by tuning the volume ratio of these constituting luminophores. Their electroluminescence characteristics including color rendering index, Commission Internationale de l'Eclairage (CIE) color coordinates, and color temperatures were evaluated as a function of forward current. The CIE-1931 chromaticity coordinates of the as-prepared WLEDs, exhibiting good stability, were slightly shifted from (0.321, 0.312) at 10 mA to (0.351, 0.322) at 30 mA, which was mainly caused by the different thermal quenching coefficients of carbon dots and ZCIS QDs.

  10. An experiment on the color rendering of different light sources

    NASA Astrophysics Data System (ADS)

    Fumagalli, Simonetta; Bonanomi, Cristian; Rizzi, Alessandro

    2013-02-01

    The color rendering index (CRI) of a light source attempts to measure how much the color appearance of objects is preserved when they are illuminated by the given light source. This problem is of great importance for various industrial and scientific fields, such as lighting architecture, design, ergonomics, etc. Usually a light source is specified through the Correlated Color Temperature or CCT. However two (or more) light sources with the same CCT but different spectral power distribution can exist. Therefore color samples viewed under two light sources with equal CCTs can appear different. Hence, the need for a method to assess the quality of a given illuminant in relation to color. Recently CRI has had a renewed interest because of the new LED-based lighting systems. They usually have a color rendering index rather low, but good preservation of color appearance and a pleasant visual appearance (visual appeal). Various attempts to develop a new color rendering index have been done so far, but still research is working for a better one. This article describes an experiment performed by human observers concerning the appearance preservation of color under some light sources, comparing it with a range of available color rendering indices.

  11. High color rendering index WLED based on YAG:Ce phosphor and CdS/ZnS core/shell quantum dots

    NASA Astrophysics Data System (ADS)

    Shen, Changyu; Li, Ke

    2009-08-01

    White LED combining of blue chip and YAG:Ce phosphor suffers from a red spectral deficiency, resulting in a relatively low value of color rendering index (CRI). In our study, for an effort to improve color rendering properties of YAG:Ce phosphor-based white LEDs, highly luminescent red-orange emitting CdS/ZnS QDs were blended with YAG:Ce phosphors. Core/shell CdS/ZnS quantum dots with the emission wavelength of 618nm, was synthesized by thermal deposition using cadmium oxide and selenium as precursors in a hot lauric acid and hexadecylamine trioctylphosphine oxide hybrid. YAG:Ce phosphor was synthesized by high-temperature solid state reaction at 900-1200°C in a slightly reducing atmosphere for 4 hours. Blends of phosphors and QDs exhibited the prominent spectral evolution with an increasing content of QDs. A hybrid white LED, which combines a blue LED with the blend of YAG phosphor and QDs with a weight ratio of 1.5:1,was demonstrated with an improved CRI value of 86.

  12. Opponent-colors approach to color rendering.

    PubMed

    Worthey, J A

    1982-01-01

    Starting with an opponent-colors formulation of color vision, two parameters, t and d, may be defined that express an illuminant's ability to realize red-green and blue-yellow contrasts of objects. For instance, calculation of t and d for daylight shows that on a gray day, color contrasts are actually reduced. By these measures, many common vapor-discharge illuminants systematically distort object colors. Because red-green contrasts contribute to border distinctness, and both types of color contrast contribute to brightness, such systematic distortions probably affect the overall clarity and brightness of what is perceived visually, Experimental data are consistent with this idea. In relation to color-constancy (retinex) experiments, it is approximately true that the visual system discounts the color of an illuminant but not its t and d.

  13. Bicolor Mn-doped CuInS{sub 2}/ZnS core/shell nanocrystals for white light-emitting diode with high color rendering index

    SciTech Connect

    Huang, Bo; Dai, Qian; Zhang, Huichao; Liao, Chen; Cui, Yiping; Zhang, Jiayu; Zhuo, Ningze; Jiang, Qingsong; Shi, Fenghua; Wang, Haibo

    2014-09-07

    We synthesized bicolor Mn-doped CuInS{sub 2} (CIS)/ZnS core/shell nanocrystals (NCs), in which Mn{sup 2+} ions and the CIS core were separated with a ZnS layer, and both Mn{sup 2+} ions and CIS cores could emit simultaneously. Transmission electron microscopy and powder X-ray diffraction measurements indicated the epitaxial growth of ZnS shell on the CuInS{sub 2} core, and electron paramagnetic resonance spectrum indicated that Mn{sup 2+} ions were on the lattice points of ZnS shell. By integrating these bicolor NCs with commercial InGaN-based blue-emitting diodes, tricolor white light-emitting diodes with color rendering index of 83 were obtained.

  14. Color rendering indices in global illumination methods

    NASA Astrophysics Data System (ADS)

    Geisler-Moroder, David; Dür, Arne

    2009-02-01

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

  15. Enhancement of the Color Rendering Index of White Organic Light-Emitting Devices Based on a Blue and Red Emitting Layer with a Y3Al5O12:Ce3+ Green Phosphor Color-Conversion Layer.

    PubMed

    Jang, J S; Lee, K S; Lee, E J; Kwon, M S; Kim, T W

    2015-01-01

    White organic light-emitting devices (WOLEDs) were fabricated utilizing blue and red emitting organic light-emitting devices and a color conversion layer (CCL) made of yttrium aluminum garnet (YAG:Ce3+) phosphors embedded into polymethylmethacrylate. The good color balance for the color conversion of the WOLEDs was achieved utilizing 20-nm blue and 10-nm red OLEDs. The electroluminescence spectrum for the fabricated device showed a white color consisting of the blue color from the 4,4-bis(2,2-diphenylethen-1-yl)bipheny layer, the red color from the tris-(8-hydroxyquinolinato) aluminum: 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran layer, and the green color from the YAG:Ce3+ phosphor. The Commission Internationale de l'Eclairage coordinates of the WOLEDs slightly shifted from (0.25, 0.23) of the blue and red emission OLEDs without phosphors to (0.34, 0.35) of the OLEDs with green phosphors, indicative of the pure white color. WOLEDs with a CCL exhibited three wavelength white emissions with a color rendering index of 86.

  16. Warm-white light-emitting diode with high color rendering index fabricated by combining trichromatic InGaN emitter with single red phosphor.

    PubMed

    Sheu, Jinn-Kong; Chen, Fu-Bang; Wang, Yen-Chin; Chang, Chih-Chiang; Huang, Shih-Hsien; Liu, Chun-Nan; Lee, Ming-Lun

    2015-04-01

    We present a trichromatic GaN-based light-emitting diode (LED) that emits near-ultraviolet (n-UV) blue and green peaks combined with red phosphor to generate white light with a low correlated color temperature (CCT) and high color rendering index (CRI). The LED structure, blue and green unipolar InGaN/GaN multiple quantum wells (MQWs) stacked with a top p-i-n structure containing an InGaN/GaN MQW emitting n-UV light, was grown epitaxially on a single substrate. The trichromatic LED chips feature a vertical conduction structure on a silicon substrate fabricated through wafer bonding and laser lift-off techniques. The blue and green InGaN/GaN MQWs were pumped with n-UV light to re-emit low-energy photons when the LEDs were electrically driven with a forward current. The emission spectrum included three peaks at approximately 405, 468, and 537 nm. Furthermore, the trichromatic LED chips were combined with red phosphor to generate white light with a CCT and CRI of approximately 2900 and 92, respectively. PMID:25968789

  17. Image-based color ink diffusion rendering.

    PubMed

    Wang, Chung-Ming; Wang, Ren-Jie

    2007-01-01

    This paper proposes an image-based painterly rendering algorithm for automatically synthesizing an image with color ink diffusion. We suggest a mathematical model with a physical base to simulate the phenomenon of color colloidal ink diffusing into absorbent paper. Our algorithm contains three main parts: a feature extraction phase, a Kubelka-Munk (KM) color mixing phase, and a color ink diffusion synthesis phase. In the feature extraction phase, the information of the reference image is simplified by luminance division and color segmentation. In the color mixing phase, the KM theory is employed to approximate the result when one pigment is painted upon another pigment layer. Then, in the color ink diffusion synthesis phase, the physically-based model that we propose is employed to simulate the result of color ink diffusion in absorbent paper using a texture synthesis technique. Our image-based ink diffusing rendering (IBCIDR) algorithm eliminates the drawback of conventional Chinese ink simulations, which are limited to the black ink domain, and our approach demonstrates that, without using any strokes, a color image can be automatically converted to the diffused ink style with a visually pleasing appearance.

  18. Modulating dual-wavelength multiple quantum wells in white light emitting diodes to suppress efficiency droop and improve color rendering index

    SciTech Connect

    Zhao, Yukun; Wang, Shuai; Zheng, Min; Ding, Wen; Yun, Feng; Su, Xilin; Yang, Xiangrong; Liu, Shuo; Guo, Maofeng; Zhang, Ye

    2015-10-14

    In this paper, gallium nitride (GaN) based white light-emitting diodes (WLEDs) with modulated quantities of blue (In{sub 0.15}Ga{sub 0.85}N) quantum wells (QWs) and cyan QWs (In{sub 0.18}Ga{sub 0.82}N) in multiple QW (MQW) structures have been investigated numerically and experimentally. It is demonstrated that the optical performance of LEDs is sensitive to the quantities of cyan QWs in dual-wavelength MQW structures. Compared to the LEDs with respective 0, 4, and 8 cyan QWs (12 QWs in total), the optical performance of the sample with 6 cyan QWs is the best. The deterioration of the optical performance in the sample with less (4 pairs) cyan QWs or more (8 pairs) cyan QWs than 6 cyan QWs may be ascribed to weakened reservoir effect or more defects induced. Compared to conventional blue LEDs (12 blue QWs), the sample with 6 cyan QWs could effectively suppress the efficiency droop (the experimental droop ratio decreases from 50.3% to 39.5% at 80 A/cm{sup 2}) and significantly improve the color rendering index (CRI, increases from 66.4 to 77.0) simultaneously. We attribute the droop suppression to the strengthened reservoir effect and carrier confinement of deeper QWs (higher indium composition) incorporated in the dual-wavelength MQW structures, which lead to the better hole spreading and enhanced radiative recombination. Meanwhile, the remarkable experimental CRI improvement may result from the wider full-width at half-maximum of electroluminescence spectra and higher cyan intensity in WLED chips with dual-wavelength MQW structures.

  19. Realistic fetus skin color processing for ultrasound volume rendering

    NASA Astrophysics Data System (ADS)

    Kim, Yun-Tae; Kim, Kyuhong; Park, Sung-Chan; Kang, Jooyoung; Kim, Jung-Ho

    2014-01-01

    This paper proposes realistic fetus skin color processing using a 2D color map and a tone mapping function (TMF) for ultrasound volume rendering. The contributions of this paper are a 2D color map generated through a gamut model of skin color and a TMF that depends on the lighting position. First, the gamut model of fetus skin color is calculated by color distribution of baby images. The 2D color map is created using a gamut model for tone mapping of ray casting. For the translucent effect, a 2D color map in which lightness is inverted is generated. Second, to enhance the contrast of rendered images, the luminance, color, and tone curve TMF parameters are changed using 2D Gaussian function that depends on the lighting position. The experimental results demonstrate that the proposed method achieves better realistic skin color reproduction than the conventional method.

  20. Color-rendering indices in global illumination methods

    NASA Astrophysics Data System (ADS)

    Geisler-Moroder, David; Dür, Arne

    2009-10-01

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

  1. Facile Atmospheric Pressure Synthesis of High Thermal Stability and Narrow-Band Red-Emitting SrLiAl3N4:Eu(2+) Phosphor for High Color Rendering Index White Light-Emitting Diodes.

    PubMed

    Zhang, Xuejie; Tsai, Yi-Ting; Wu, Shin-Mou; Lin, Yin-Chih; Lee, Jyh-Fu; Sheu, Hwo-Shuenn; Cheng, Bing-Ming; Liu, Ru-Shi

    2016-08-01

    Red phosphors (e.g., SrLiAl3N4:Eu(2+)) with high thermal stability and narrow-band properties are urgently explored to meet the next-generation high-power white light-emitting diodes (LEDs). However, to date, synthesis of such phosphors remains an arduous task. Herein, we report, for the first time, a facile method to synthesize SrLiAl3N4:Eu(2+) through Sr3N2, Li3N, Al, and EuN under atmospheric pressure. The as-synthesized narrow-band red-emitting phosphor exhibits excellent thermal stability, including small chromaticity shift and low thermal quenching. Intriguingly, the title phosphor shows an anomalous increase in theoretical lumen equivalent with the increase of temperature as a result of blue shift and band broadening of the emission band, which is crucial for high-power white LEDs. Utilizing the title phosphor, commercial YAG:Ce(3+), and InGaN-based blue LED chip, a proof-of-concept warm white LEDs with a color rendering index (CRI) of 91.1 and R9 = 68 is achieved. Therefore, our results highlight that this method, which is based on atmospheric pressure synthesis, may open a new means to explore narrow-band-emitting nitride phosphor. In addition, the underlying requirements to design Eu(2+)-doped narrow-band-emitting phosphors were also summarized. PMID:27403812

  2. Facile Atmospheric Pressure Synthesis of High Thermal Stability and Narrow-Band Red-Emitting SrLiAl3N4:Eu(2+) Phosphor for High Color Rendering Index White Light-Emitting Diodes.

    PubMed

    Zhang, Xuejie; Tsai, Yi-Ting; Wu, Shin-Mou; Lin, Yin-Chih; Lee, Jyh-Fu; Sheu, Hwo-Shuenn; Cheng, Bing-Ming; Liu, Ru-Shi

    2016-08-01

    Red phosphors (e.g., SrLiAl3N4:Eu(2+)) with high thermal stability and narrow-band properties are urgently explored to meet the next-generation high-power white light-emitting diodes (LEDs). However, to date, synthesis of such phosphors remains an arduous task. Herein, we report, for the first time, a facile method to synthesize SrLiAl3N4:Eu(2+) through Sr3N2, Li3N, Al, and EuN under atmospheric pressure. The as-synthesized narrow-band red-emitting phosphor exhibits excellent thermal stability, including small chromaticity shift and low thermal quenching. Intriguingly, the title phosphor shows an anomalous increase in theoretical lumen equivalent with the increase of temperature as a result of blue shift and band broadening of the emission band, which is crucial for high-power white LEDs. Utilizing the title phosphor, commercial YAG:Ce(3+), and InGaN-based blue LED chip, a proof-of-concept warm white LEDs with a color rendering index (CRI) of 91.1 and R9 = 68 is achieved. Therefore, our results highlight that this method, which is based on atmospheric pressure synthesis, may open a new means to explore narrow-band-emitting nitride phosphor. In addition, the underlying requirements to design Eu(2+)-doped narrow-band-emitting phosphors were also summarized.

  3. Changing the color of textiles with realistic visual rendering

    NASA Astrophysics Data System (ADS)

    Hébert, Mathieu; Henckens, Lambert; Barbier, Justine; Leboulleux, Lucie; Page, Marine; Roujas, Lucie; Cazier, Anthony

    2015-03-01

    Fast and easy preview of a fabric without having to produce samples would be very profitable for textile designers, but remains a technological challenge. As a first step towards this objective, we study the possibility of making images of a real sample, and changing virtually the colors of its yarns while preserving the shine and shadow texture. We consider two types of fabrics: Jacquard weave fabrics made of polyester warp and weft yarns of different colors, and satin ribbons made of polyester and metallic yarns. For the Jacquard fabric, we make a color picture with a scanner on a sample in which the yarns have contrasted colors, threshold this image in order to distinguish the pixels corresponding to each yarn, and accordingly modify their hue and chroma values. This method is simple to operate but do not enable to simulate the angle-dependent shine. A second method, tested on the satin ribbon made of black polyester and achromatic metallic yarns, is based on polarized imaging. We analyze the polarization state of the reflected light which is different for dielectric and metallic materials illuminated by polarized light. We then add a fixed color value to the pixels representing the polyester yarns and modify the hue and chroma of the pixels representing the metallic yarns. This was performed for many incident angles of light, in order to render the twinkling effect displayed by these ribbons. We could verify through a few samples that the simulated previews reproduce real pictures with visually acceptable accuracy.

  4. Adaptive color rendering of maps for users with color vision deficiencies

    NASA Astrophysics Data System (ADS)

    Kvitle, Anne Kristin; Green, Phil; Nussbaum, Peter

    2015-01-01

    A map is an information design object for which canonical colors for the most common elements are well established. For a CVD observer, it may be difficult to discriminate between such elements - for example, it may be hard to distinguish a red road from a green landscape on the basis of color alone. We address this problem through an adaptive color schema in which the conspicuity of elements in a map to the individual user is maximized. This paper outlines a method to perform adaptive color rendering of map information for users with color vision deficiencies. The palette selection method is based on a pseudo-color palette generation technique which constrains colors to those which lie on the boundary of a reference object color gamut. A user performs a color vision discrimination task, and based on the results of the test, a palette of colors is selected using the pseudo-color palette generation method. This ensures that the perceived difference between palette elements is high but which retains the canonical color of well-known elements as far as possible. We show examples of color palettes computed for a selection of normal and CVD observers, together with maps rendered using these palettes.

  5. Increasing color saturation by optimizing light spectra constrained on color rendering properties.

    PubMed

    Wu, Haining; Dong, Jianfei; Zhang, Guoqi

    2016-02-01

    Enhancing the color saturation of objects via illumination with specially designed light spectra is promising in many commercial and scientific applications. Existing literature has focused on studying the colors that can be rendered by white light with various correlated color temperatures, and by the mixed light from various monochromatic light-emitting diodes. However, very little literature has been devoted to methods that can actively configure the light spectrum to enhance the color saturation of an arbitrary object. This paper proposes an optimization-based method to extend the gamut that can be achieved by a given polychromatic lamp toward a chosen direction, i.e., to increase the saturation of a specific color. Moreover, to trade-off the increased saturation of a color sample with the reduced colorfulness of other samples, constraints with tunable thresholds are imposed to the optimization problem to bound the variation of a contrast color sample. In addition, the effect of uncontrollable ambient light can be taken into account by mild modifications of the optimization problem. Simulation results show that the optimized light spectrum can effectively enhance the saturation of any specific color, while maintaining the other rendered colors as intact as possible. Visual experiments have also been conducted with 22 human subjects, whose responses agree with the simulation results. PMID:26831770

  6. Increasing color saturation by optimizing light spectra constrained on color rendering properties.

    PubMed

    Wu, Haining; Dong, Jianfei; Zhang, Guoqi

    2016-02-01

    Enhancing the color saturation of objects via illumination with specially designed light spectra is promising in many commercial and scientific applications. Existing literature has focused on studying the colors that can be rendered by white light with various correlated color temperatures, and by the mixed light from various monochromatic light-emitting diodes. However, very little literature has been devoted to methods that can actively configure the light spectrum to enhance the color saturation of an arbitrary object. This paper proposes an optimization-based method to extend the gamut that can be achieved by a given polychromatic lamp toward a chosen direction, i.e., to increase the saturation of a specific color. Moreover, to trade-off the increased saturation of a color sample with the reduced colorfulness of other samples, constraints with tunable thresholds are imposed to the optimization problem to bound the variation of a contrast color sample. In addition, the effect of uncontrollable ambient light can be taken into account by mild modifications of the optimization problem. Simulation results show that the optimized light spectrum can effectively enhance the saturation of any specific color, while maintaining the other rendered colors as intact as possible. Visual experiments have also been conducted with 22 human subjects, whose responses agree with the simulation results.

  7. Image indexing using color correlograms

    DOEpatents

    Huang, Jing; Kumar, Shanmugasundaram Ravi; Mitra, Mandar; Zhu, Wei-Jing

    2001-01-01

    A color correlogram is a three-dimensional table indexed by color and distance between pixels which expresses how the spatial correlation of color changes with distance in a stored image. The color correlogram may be used to distinguish an image from other images in a database. To create a color correlogram, the colors in the image are quantized into m color values, c.sub.i . . . c.sub.m. Also, the distance values k.epsilon.[d] to be used in the correlogram are determined where [d] is the set of distances between pixels in the image, and where dmax is the maximum distance measurement between pixels in the image. Each entry (i, j, k) in the table is the probability of finding a pixel of color c.sub.i at a selected distance k from a pixel of color c.sub.i. A color autocorrelogram, which is a restricted version of the color correlogram that considers color pairs of the form (i,i) only, may also be used to identify an image.

  8. Using nanoimprint lithography to improve the light extraction efficiency and color rendering of dichromatic white light-emitting diodes.

    PubMed

    Lee, Yang-Chun; Chen, Hsuen-Li; Lu, Chih-Yu; Wu, Hung-Sen; Chou, Yung-Fang; Chen, Szu-Huang

    2015-10-21

    Despite the efficiency of gallium nitride (GaN)-based blue light-emitting diodes (LEDs), the light extraction arising from the packaging of the phosphor remains an important issue when enhancing the performance of dichromatic white LEDs. In this study, we employed a simple, inexpensive nanoimprinting process to increase both the light extraction efficiency and color rendering of dichromatic white LEDs. We employed the rigorous coupled wave approach (RCWA) to optimize the light extraction efficiency of yellow and blue light. We found that the presence of the light extracting structures could also improve the color rendering of the dichromatic white LEDs, due to the different light extraction efficiencies of the textured structures at different wavelengths. After fabricating inverted pyramid structures on the surface of the encapsulation layer, the intensity of the blue light at 455 nm increased by 20%. When we further considered the color rendering and correlated color temperature (CCT), the enhancement of blue light was 15% and that of yellow light was 4%. Meanwhile, the light extraction of the intensity dip near 490 nm was enhanced significantly (by 25%), resulting in an increased dip-intensity of light at 490 nm relative to the intensities of the blue and yellow light. Accordingly, the color rendering index (CRI) of this dichromatic white LED increased from 69 to 73. Because it improved both the light extraction efficiency and color rendering of dichromatic white LEDs, this simple method should be very helpful for enhancing their applications in solid state illumination. PMID:26381707

  9. A two-metric proposal to specify the color-rendering properties of light sources for retail lighting

    NASA Astrophysics Data System (ADS)

    Freyssinier, Jean Paul; Rea, Mark

    2010-08-01

    Lighting plays an important role in supporting retail operations, from attracting customers, to enabling the evaluation of merchandise, to facilitating the completion of the sale. Lighting also contributes to the identity, comfort, and visual quality of a retail store. With the increasing availability and quality of white LEDs, retail lighting specifiers are now considering LED lighting in stores. The color rendering of light sources is a key factor in supporting retail lighting goals and thus influences a light source's acceptance by users and specifiers. However, there is limited information on what consumers' color preferences are, and metrics used to describe the color properties of light sources often are equivocal and fail to predict preference. The color rendering of light sources is described in the industry solely by the color rendering index (CRI), which is only indirectly related to human perception. CRI is intended to characterize the appearance of objects illuminated by the source and is increasingly being challenged because new sources are being developed with increasingly exotic spectral power distributions. This paper discusses how CRI might be augmented to better use it in support of the design objectives for retail merchandising. The proposed guidelines include the use of gamut area index as a complementary metric to CRI for assuring good color rendering.

  10. Using nanoimprint lithography to improve the light extraction efficiency and color rendering of dichromatic white light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Lee, Yang-Chun; Chen, Hsuen-Li; Lu, Chih-Yu; Wu, Hung-Sen; Chou, Yung-Fang; Chen, Szu-Huang

    2015-10-01

    Despite the efficiency of gallium nitride (GaN)-based blue light-emitting diodes (LEDs), the light extraction arising from the packaging of the phosphor remains an important issue when enhancing the performance of dichromatic white LEDs. In this study, we employed a simple, inexpensive nanoimprinting process to increase both the light extraction efficiency and color rendering of dichromatic white LEDs. We employed the rigorous coupled wave approach (RCWA) to optimize the light extraction efficiency of yellow and blue light. We found that the presence of the light extracting structures could also improve the color rendering of the dichromatic white LEDs, due to the different light extraction efficiencies of the textured structures at different wavelengths. After fabricating inverted pyramid structures on the surface of the encapsulation layer, the intensity of the blue light at 455 nm increased by 20%. When we further considered the color rendering and correlated color temperature (CCT), the enhancement of blue light was 15% and that of yellow light was 4%. Meanwhile, the light extraction of the intensity dip near 490 nm was enhanced significantly (by 25%), resulting in an increased dip-intensity of light at 490 nm relative to the intensities of the blue and yellow light. Accordingly, the color rendering index (CRI) of this dichromatic white LED increased from 69 to 73. Because it improved both the light extraction efficiency and color rendering of dichromatic white LEDs, this simple method should be very helpful for enhancing their applications in solid state illumination.Despite the efficiency of gallium nitride (GaN)-based blue light-emitting diodes (LEDs), the light extraction arising from the packaging of the phosphor remains an important issue when enhancing the performance of dichromatic white LEDs. In this study, we employed a simple, inexpensive nanoimprinting process to increase both the light extraction efficiency and color rendering of dichromatic white

  11. Energy-Efficient, High-Color-Rendering LED Lamps Using Oxyfluoride and Fluoride Phosphors

    SciTech Connect

    Setlur, A.; Radkov, E; Henderson, C; Her, J; Srivastava, A; Karkada, N; Kishore, M; Kumar, N; Aesram, D; et al.

    2010-01-01

    LED lamps using phosphor downconversion can be designed to replace incandescent or halogen sources with a 'warm-white' correlated color temperature (CCT) of 2700-3200 K and a color rendering index (CRI) greater than 90. However, these lamps have efficacies of {approx}70% of standard 'cool-white' LED packages (CCT = 4500-6000 K; CRI = 75-80). In this report, we describe structural and luminescence properties of fluoride and oxyfluoride phosphors, specifically a (Sr,Ca){sub 3}(Al,Si)O{sub 4}(F,O):Ce{sup 3+} yellow-green phosphor and a K{sub 2}TiF{sub 6}:Mn{sup 4+} red phosphor, that can reduce this gap and therefore meet the spectral and efficiency requirements for high-efficacy LED lighting. LED lamps with a warm-white color temperature (3088 K), high CRI (90), and an efficacy of {approx}82 lm/W are demonstrated using these phosphors. This efficacy is {approx}85% of comparable cool-white lamps using typical Y{sub 3}Al{sub 5}O{sub 12}:Ce{sup 3+}-based phosphors, significantly reducing the efficacy gap between warm-white and cool-white LED lamps that use phosphor downconversion.

  12. High Dynamic Range Image rendering of color in chameleons' camouflage using optical thin films

    NASA Astrophysics Data System (ADS)

    Prusten, Mark

    2008-08-01

    High Dynamic Range Image (HDRI) rendering and animation of color in the camouflage of chameleons is developed utilizing thin film optics. Chameleons are a lizard species, and have the ability to change their skin color. This change in color is an expression of the physical and physiological conditions of the lizard, and plays a part in communication. The different colors that can be produced depending on the species include pink, blue, red, orange, green, black, brown and yellow. The modeling, simulation, and rendering of the color, which their skin incorporates, thin film optical stacks. The skin of a chameleon has four layers, which together produce various colors. The outside transparent layer has chromatophores cells, of two kinds of color, yellow and red. Next there are two more layers that reflect light: one blue and the other white. The innermost layer contains dark pigment granules or melanophore cells that influences the amount of reflected light. All of these pigment cells can rapidly relocate their pigments, thereby influencing the color of the chameleon. Techniques like subsurface scattering, the simulation of volumetric scattering of light underneath the objects surface, and final gathering are defined in custom shaders and material phenomena for the renderer. The workflow developed to model the chameleon's skin is also applied to simulation and rendering of hair and fur camouflage, which does not exist in nature.

  13. Accelerating Time-Varying Hardware Volume Rendering Using TSP Trees and Color-Based Error Metrics

    NASA Technical Reports Server (NTRS)

    Ellsworth, David; Chiang, Ling-Jen; Shen, Han-Wei; Kwak, Dochan (Technical Monitor)

    2000-01-01

    This paper describes a new hardware volume rendering algorithm for time-varying data. The algorithm uses the Time-Space Partitioning (TSP) tree data structure to identify regions within the data that have spatial or temporal coherence. By using this coherence, the rendering algorithm can improve performance when the volume data is larger than the texture memory capacity by decreasing the amount of textures required. This coherence can also allow improved speed by appropriately rendering flat-shaded polygons instead of textured polygons, and by not rendering transparent regions. To reduce the polygonization overhead caused by the use of the hierarchical data structure, we introduce an optimization method using polygon templates. The paper also introduces new color-based error metrics, which more accurately identify coherent regions compared to the earlier scalar-based metrics. By showing experimental results from runs using different data sets and error metrics, we demonstrate that the new methods give substantial improvements in volume rendering performance.

  14. [Study of spectrum drifting of primary colors and its impact on color rendering properties].

    PubMed

    Cui, Xiao-yan; Zhang, Xiao-dong

    2012-08-01

    LEDs are currently used widely to display text, graphics and images in large screens. With red, green and blue LEDs as three primary colors, color rendition will be realized through color mixing. However, LEDs' spectrum will produce drifts with the changes in the temperature environment. With the changes in the driving current simulating changes in the temperature, the three primary color LEDs' spectral drifts were tested, and the drift characteristics of the three primary colors were obtained respectively. Based on the typical characteristics of the LEDs and the differences between LEDs with different colors in composition and molecular structure, the paper analyzed the reason for the spectrum drifts and the drift characteristics of different color LEDs, and proposed the equations of spectrum drifts. Putting the experimental data into the spectrum drift equations, the paper analyzed the impacts of primary colors on the mixed color, pointed out a way to reduce the chromatic aberration, and provided the theory for engineering application of color LEDs.

  15. Ammonium hydroxide modulated synthesis of high-quality fluorescent carbon dots for white LEDs with excellent color rendering properties

    NASA Astrophysics Data System (ADS)

    Wang, Shengda; Zhu, Zhifeng; Chang, Yajing; Wang, Hui; Yuan, Nan; Li, Guopeng; Yu, Dabin; Jiang, Yang

    2016-07-01

    A novel type of aqueous fluorescent carbon dot (CD) was synthesized using citric acid as the only carbon source via an ammonium hydroxide modulated method, providing a blue color gamut. The amino group is considered to be the key factor in the high fluorescence of CDs and a model is established to investigate the mechanism of fluorescence. In addition, white light-emitting diodes (WLEDs) are fabricated by utilizing the prepared CDs and rare earth luminescent materials (SrSi2O2N2:Eu and Sr2Si5N8:Eu) as color conversion layers and UV-LED chips as the excitation light source. The WLEDs produce bright white light with attractive color rendering properties including a color rendering index of up to 95.1, a CIE coordinate of (0.33, 0.37), and a T c of 5447 K under a 100 mA driven current, indicating that the CDs are promising in the field of optoelectronic devices.

  16. Showing their true colors: a practical approach to volume rendering from serial sections

    PubMed Central

    2010-01-01

    Background In comparison to more modern imaging methods, conventional light microscopy still offers a range of substantial advantages with regard to contrast options, accessible specimen size, and resolution. Currently, tomographic image data in particular is most commonly visualized in three dimensions using volume rendering. To date, this method has only very rarely been applied to image stacks taken from serial sections, whereas surface rendering is still the most prevalent method for presenting such data sets three-dimensionally. The aim of this study was to develop standard protocols for volume rendering of image stacks of serial sections, while retaining the benefits of light microscopy such as resolution and color information. Results Here we provide a set of protocols for acquiring high-resolution 3D images of diverse microscopic samples through volume rendering based on serial light microscopical sections using the 3D reconstruction software Amira (Visage Imaging Inc.). We overcome several technical obstacles and show that these renderings are comparable in quality and resolution to 3D visualizations using other methods. This practical approach for visualizing 3D micro-morphology in full color takes advantage of both the sub-micron resolution of light microscopy and the specificity of histological stains, by combining conventional histological sectioning techniques, digital image acquisition, three-dimensional image filtering, and 3D image manipulation and visualization technologies. Conclusions We show that this method can yield "true"-colored high-resolution 3D views of tissues as well as cellular and sub-cellular structures and thus represents a powerful tool for morphological, developmental, and comparative investigations. We conclude that the presented approach fills an important gap in the field of micro-anatomical 3D imaging and visualization methods by combining histological resolution and differentiation of details with 3D rendering of whole

  17. High-color-rendering light sources consisting of a 350-nm ultraviolet light-emitting diode and three-basal-color phosphors

    NASA Astrophysics Data System (ADS)

    Nishida, Toshio; Ban, Tomoyuki; Kobayashi, Naoki

    2003-06-01

    The high-color-rendering (HCR) potential of the light sources consisting of 350-nm ultraviolet light-emitting diodes (UV-LED) and three-basal-color phosphors was simulated and experimentally confirmed. By using an AlGaN-based UV-LED as an excitation source at the 350-nm wavelength, we measured fluorescence spectra of three-basal-color phosphors, and simulated the optimum phosphor mixture based on the Commission Internationale de l'Eclairage standard light sources D75, D65, D55, D50, C, and A, with HCR indexes (Ra) over 92. We confirmed the potential of HCR of this light source consisting of 350-nm UV-LED and three-basal-color phosphors, by obtaining Ra=86˜89 of the incandescent type of standard light source A experimentally. Such high Ra are due to the highly monochromatic UV-LED emission and the wide spectral separation between the UV excitation (350 nm) and visible fluorescences. This combination also provides a diffusive, nonglare light source with highly steady color independent of the emission orientation. We also examined the importance of the separation between the excitation wavelength and the fluorescence emission wavelength for practical lighting applications.

  18. High color-rendering warm-white lamps using quantum-dot color conversion films.

    PubMed

    Lien, Jiun-Yi; Chen, Chih-Jung; Chiang, Ray-Kuang; Wang, Sue-Lein

    2016-07-11

    Colloidal quantum dots are promising next-generation phosphors to enhance the color rendition of light-emitting diodes (LEDs) while minimizing the brightness droop. In order to exploit the beneficial tunability of quantum dots for highly efficient devices, optimization and determination of the performance limit are of crucial importance. In this work, a facile preparation process of red-emission quantum dot films and simulation algorithm for fitting this film with two commercial LED flat lamps to the optimized performance are developed. Based on the algorithm, one lamp improves from cold-white light (8669 K) with poor color rendition (Ra = 72) and luminous efficacy (85 lm/W) to warm-white light (2867 K) with Ra = 90.8 and R9 = 74.9, and the other reaches Ra = 93 ∼ 95. Impressively, the brightness droop is only about 15 ∼ 20% and the luminous efficacy of 68 lm/W is achieved. Furthermore, our device shows reliability over 1000 hours with only PET (polyethylene-terephthalate) films as the barrier, indicating that this auxiliary red-emission film can be easily applied to improve the color rendition of most commercial LED flat lamps. PMID:27410891

  19. High color-rendering warm-white lamps using quantum-dot color conversion films.

    PubMed

    Lien, Jiun-Yi; Chen, Chih-Jung; Chiang, Ray-Kuang; Wang, Sue-Lein

    2016-07-11

    Colloidal quantum dots are promising next-generation phosphors to enhance the color rendition of light-emitting diodes (LEDs) while minimizing the brightness droop. In order to exploit the beneficial tunability of quantum dots for highly efficient devices, optimization and determination of the performance limit are of crucial importance. In this work, a facile preparation process of red-emission quantum dot films and simulation algorithm for fitting this film with two commercial LED flat lamps to the optimized performance are developed. Based on the algorithm, one lamp improves from cold-white light (8669 K) with poor color rendition (Ra = 72) and luminous efficacy (85 lm/W) to warm-white light (2867 K) with Ra = 90.8 and R9 = 74.9, and the other reaches Ra = 93 ∼ 95. Impressively, the brightness droop is only about 15 ∼ 20% and the luminous efficacy of 68 lm/W is achieved. Furthermore, our device shows reliability over 1000 hours with only PET (polyethylene-terephthalate) films as the barrier, indicating that this auxiliary red-emission film can be easily applied to improve the color rendition of most commercial LED flat lamps.

  20. Four-color laser white illuminant demonstrating high color-rendering quality

    SciTech Connect

    Neumann, A.; Wierer, J. J.; Davis, W.; Ohno, Y.; Brueck, S. R.; Tsao, J.Y.

    2011-07-01

    Solid-state lighting is currently based on light-emitting diodes (LEDs) and phosphors. Solid-state lighting based on lasers would offer significant advantages including high potential efficiencies at high current densities. Light emitted from lasers, however, has a much narrower spectral line-width than light emitted from LEDs or phosphors. Therefore it is a common belief that white light produced by a set of lasers of different colors would not be of high enough quality for general illumination. We tested this belief experimentally, and found the opposite to be true. This result paves the way for the use of lasers in solid-state lighting.

  1. Color analysis and image rendering of woodblock prints with oil-based ink

    NASA Astrophysics Data System (ADS)

    Horiuchi, Takahiko; Tanimoto, Tetsushi; Tominaga, Shoji

    2012-01-01

    This paper proposes a method for analyzing the color characteristics of woodblock prints having oil-based ink and rendering realistic images based on camera data. The analysis results of woodblock prints show some characteristic features in comparison with oil paintings: 1) A woodblock print can be divided into several cluster areas, each with similar surface spectral reflectance; and 2) strong specular reflection from the influence of overlapping paints arises only in specific cluster areas. By considering these properties, we develop an effective rendering algorithm by modifying our previous algorithm for oil paintings. A set of surface spectral reflectances of a woodblock print is represented by using only a small number of average surface spectral reflectances and the registered scaling coefficients, whereas the previous algorithm for oil paintings required surface spectral reflectances of high dimension at all pixels. In the rendering process, in order to reproduce the strong specular reflection in specific cluster areas, we use two sets of parameters in the Torrance-Sparrow model for cluster areas with or without strong specular reflection. An experiment on a woodblock printing with oil-based ink was performed to demonstrate the feasibility of the proposed method.

  2. Modeling a color-rendering operator for high dynamic range images using a cone-response function

    NASA Astrophysics Data System (ADS)

    Choi, Ho-Hyoung; Kim, Gi-Seok; Yun, Byoung-Ju

    2015-09-01

    Tone-mapping operators are the typical algorithms designed to produce visibility and the overall impression of brightness, contrast, and color of high dynamic range (HDR) images on low dynamic range (LDR) display devices. Although several new tone-mapping operators have been proposed in recent years, the results of these operators have not matched those of the psychophysical experiments based on the human visual system. A color-rendering model that is a combination of tone-mapping and cone-response functions using an XYZ tristimulus color space is presented. In the proposed method, the tone-mapping operator produces visibility and the overall impression of brightness, contrast, and color in HDR images when mapped onto relatively LDR devices. The tone-mapping resultant image is obtained using chromatic and achromatic colors to avoid well-known color distortions shown in the conventional methods. The resulting image is then processed with a cone-response function wherein emphasis is placed on human visual perception (HVP). The proposed method covers the mismatch between the actual scene and the rendered image based on HVP. The experimental results show that the proposed method yields an improved color-rendering performance compared to conventional methods.

  3. Indexing and retrieval of color images using vector quantization

    NASA Astrophysics Data System (ADS)

    Panchanathan, Sethuraman; Huang, Changan

    1999-10-01

    Image and Video indexing is becoming popular with the increasing volumes of visual information that is being stored and transmitted in various multimedia applications. An important focus of the upcoming MPEG 7 standard is on indexing and retrieval of multimedia data. The visual information can be indexed using the spatial (color, texture, shape, sketch, etc.) and temporal (motion, camera operations, etc.) features. Since multimedia data is likely to be stored in compressed form, indexing the information in compressed domain entails savings in compute time and storage space. In this paper, we present a novel indexing and retrieval technique using vector quantization of color images. Color is an important feature for indexing the visual information. Several color based indexing schemes have been reported in the recent literature. Vector Quantization (VQ) is a popular compression technique for low-power applications. Indexing the visual information based on VQ features such as luminance codebook and labels have also been recently presented in the literature. Previous VQ-based indexing techniques describes the entire image content by modeling the histogram of the image without taking into account the location of colors, which may result in unsatisfactory retrieval. We propose to incorporate spatial information in the content representation in VQ-compressed domain. We employ the luminance and chrominance codebooks trained and generated from wavelet-vector-quantized (WVQ) images, in which the images are first decomposed using wavelet transform followed by vector quantization of the transform coefficients. The labels, and the usage maps corresponding to the utilization pattern of codebooks for the individual images serve as indices to the associated color information contained in the images. Hence, the VQ compression parameters serve the purpose of indexing resulting in joint compression and indexing of the color information. Our simulations indicate superior indexing and

  4. Spectral estimation from laser scanner data for accurate color rendering of objects

    NASA Astrophysics Data System (ADS)

    Baribeau, Rejean

    2002-06-01

    Estimation methods are studied for the recovery of the spectral reflectance across the visible range from the sensing at just three discrete laser wavelengths. Methods based on principal component analysis and on spline interpolation are judged based on the CIE94 color differences for some reference data sets. These include the Macbeth color checker, the OSA-UCS color charts, some artist pigments, and a collection of miscellaneous surface colors. The optimal three sampling wavelengths are also investigated. It is found that color can be estimated with average accuracy ΔE94 = 2.3 when optimal wavelengths 455 nm, 540 n, and 610 nm are used.

  5. Virtual Exploration and Comparison of Linear Mastoid Drilling Trajectories with True-Color Volume Rendering and the Visible Ear Dataset

    PubMed Central

    KAHRS, Lueder A.; LABADIE, Robert F.

    2015-01-01

    This paper provides instructions for a virtual exploration and self-study of surgical approaches within the temporal bone. Linear drilling trajectories in the sense of keyhole accesses are compared with free true-color rendering techniques to introduce and evaluate new otologic approaches. On the basis of free cyro-histology image data from a temporal bone six different drill canals are presented. Such a virtual method has the potential to be a first step of investigation of new surgical approaches before moving to cadaver testing. PMID:23400159

  6. Virtual exploration and comparison of linear mastoid drilling trajectories with true-color volume rendering and the visible ear dataset.

    PubMed

    Kahrs, Lueder A; Labadie, Robert F

    2013-01-01

    This paper provides instructions for a virtual exploration and self-study of surgical approaches within the temporal bone. Linear drilling trajectories in the sense of "keyhole" accesses are compared with true-color rendering techniques using freeware to introduce and evaluate new otologic approaches. On the basis of public-domain cyro-histology image data from a temporal bone six different drill trajectories are presented. This virtual method has the potential to be a first step in investigation of new surgical approaches before moving to cadaver testing.

  7. Usage of data-encoded web maps with client side color rendering for combined data access, visualization, and modeling purposes

    NASA Astrophysics Data System (ADS)

    Pliutau, Denis; Prasad, Narasimha S.

    2013-05-01

    Current approaches to satellite observation data storage and distribution implement separate visualization and data access methodologies which often leads to the need in time consuming data ordering and coding for applications requiring both visual representation as well as data handling and modeling capabilities. We describe an approach we implemented for a data-encoded web map service based on storing numerical data within server map tiles and subsequent client side data manipulation and map color rendering. The approach relies on storing data using the lossless compression Portable Network Graphics (PNG) image data format which is natively supported by web-browsers allowing on-the-fly browser rendering and modification of the map tiles. The method is easy to implement using existing software libraries and has the advantage of easy client side map color modifications, as well as spatial subsetting with physical parameter range filtering. This method is demonstrated for the ASTER-GDEM elevation model and selected MODIS data products and represents an alternative to the currently used storage and data access methods. One additional benefit includes providing multiple levels of averaging due to the need in generating map tiles at varying resolutions for various map magnification levels. We suggest that such merged data and mapping approach may be a viable alternative to existing static storage and data access methods for a wide array of combined simulation, data access and visualization purposes.

  8. Usage of Data-Encoded Web Maps with Client Side Color Rendering for Combined Data Access, Visualization and Modeling Purposes

    NASA Technical Reports Server (NTRS)

    Pliutau, Denis; Prasad, Narashimha S.

    2013-01-01

    Current approaches to satellite observation data storage and distribution implement separate visualization and data access methodologies which often leads to the need in time consuming data ordering and coding for applications requiring both visual representation as well as data handling and modeling capabilities. We describe an approach we implemented for a data-encoded web map service based on storing numerical data within server map tiles and subsequent client side data manipulation and map color rendering. The approach relies on storing data using the lossless compression Portable Network Graphics (PNG) image data format which is natively supported by web-browsers allowing on-the-fly browser rendering and modification of the map tiles. The method is easy to implement using existing software libraries and has the advantage of easy client side map color modifications, as well as spatial subsetting with physical parameter range filtering. This method is demonstrated for the ASTER-GDEM elevation model and selected MODIS data products and represents an alternative to the currently used storage and data access methods. One additional benefit includes providing multiple levels of averaging due to the need in generating map tiles at varying resolutions for various map magnification levels. We suggest that such merged data and mapping approach may be a viable alternative to existing static storage and data access methods for a wide array of combined simulation, data access and visualization purposes.

  9. FMRI-adaptation to highly-rendered color photographs of animals and manipulable artifacts during a classification task.

    PubMed

    Chouinard, Philippe A; Goodale, Melvyn A

    2012-02-01

    We used fMRI to identify brain areas that adapted to either animals or manipulable artifacts while participants classified highly-rendered color photographs into subcategories. Several key brain areas adapted more strongly to one class of objects compared to the other. Namely, we observed stronger adaptation for animals in the lingual gyrus bilaterally, which are known to analyze the color of objects, and in the right frontal operculum and in the anterior insular cortex bilaterally, which are known to process emotional content. In contrast, the left anterior intraparietal sulcus, which is important for configuring the hand to match the three-dimensional structure of objects during grasping, adapted more strongly to manipulable artifacts. Contrary to what a previous study has found using gray-scale photographs, we did not replicate categorical-specific adaptation in the lateral fusiform gyrus for animals and categorical-specific adaptation in the medial fusiform gyrus for manipulable artifacts. Both categories of objects adapted strongly in the fusiform gyrus without any clear preference in location along its medial-lateral axis. We think that this is because the fusiform gyrus has an important role to play in color processing and hence its responsiveness to color stimuli could be very different than its responsiveness to gray-scale photographs. Nevertheless, on the basis of what we found, we propose that the recognition and subsequent classification of animals may depend primarily on perceptual properties, such as their color, and on their emotional content whereas other factors, such as their function, may play a greater role for classifying manipulable artifacts.

  10. Pseudo-colored visualization of EEG activities on the human cortex using MRI-based volume rendering and Delaunay interpolation

    NASA Astrophysics Data System (ADS)

    Dimitrov, Leonid I.

    1995-04-01

    A method for a pseudo-colored smooth representation of evaluated EEG parameters on a three-dimensional reconstruction of a proband's cortex is proposed. The EEG data are obtained through standard measurements and are subsequently Fourier analyzed in order to transform them to parameters representing the signals' power and coherence changes with respect to the averaged EEG at rest. The morphological data for the 3D-reconstruction of the brain is gained through MRI-scans of the head. The three-dimensional reconstruction of the cortex is achieved by means of a graylevel gradient shading method. During rendering, each brain surface voxel (volume element) is associated with a suitable parameter value determined through an inverse distance-weighted interpolation scheme from the values evaluated for its neighbors in the Delaunay triangulation mesh between the electrodes. Following the interpolation, a mapping of the calculated surface value in the HSV color space is employed in order to achieve an expressively colored brain surface with well perceptible distinct activation regions and smooth transitions between them. The presented method provides a possibility for direct, visual comparisons of the activated brain regions of a healthy individual.

  11. Volumetric rendering and metrology of spherical gradient refractive index lens imaged by angular scan optical coherence tomography system.

    PubMed

    Yao, Jianing; Thompson, Kevin P; Ma, Bin; Ponting, Michael; Rolland, Jannick P

    2016-08-22

    In this paper, we develop the methodology, including the refraction correction, geometrical thickness correction, coordinate transformation, and layer segmentation algorithms, for 3D rendering and metrology of a layered spherical gradient refractive index (S-GRIN) lens based on the imaging data collected by an angular scan optical coherence tomography (OCT) system. The 3D mapping and rendering enables direct 3D visualization and internal defect inspection of the lens. The metrology provides assessment of the surface geometry, the lens thickness, the radii of curvature of the internal layer interfaces, and the misalignment of the internal S-GRIN distribution with respect to the lens surface. The OCT metrology results identify the manufacturing defects, and enable targeted process development for optimizing the manufacturing parameters. The newly fabricated S-GRIN lenses show up to a 7x spherical aberration reduction that allows a significantly increased utilizable effective aperture. PMID:27557217

  12. Influence of junction temperature on chromaticity and color-rendering properties of trichromatic white-light sources based on light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Chhajed, S.; Xi, Y.; Li, Y.-L.; Gessmann, Th.; Schubert, E. F.

    2005-03-01

    Trichromatic white-light sources based on light-emitting diodes (LEDs) offer a high luminous efficacy of radiation, a broad range of color temperatures and excellent color-rendering properties with color-rendering indices (CRIs) exceeding 85. An analysis of the luminous efficacy and CRI of a trichromatic light source is performed for a very broad range of wavelength combinations. The peak emission wavelength, spectral width, and the output power of LEDs strongly depend on temperature and the dependencies for red, green, and blue LEDs are established. A detailed analysis of the temperature dependence of trichromatic white LED sources reveals that the luminous efficacy decreases, the color temperature increases, the CRI decreases and the chromaticity point shifts towards the blue as the junction temperature increases. A high CRI >80 can be maintained, by adjusting the LED power ratio so that the chromaticity point is conserved.

  13. Dual emissive manganese and copper Co-doped Zn-In-S quantum dots as a single color-converter for high color rendering white-light-emitting diodes.

    PubMed

    Yuan, Xi; Ma, Ruixin; Zhang, Wenjin; Hua, Jie; Meng, Xiangdong; Zhong, Xinhua; Zhang, Jiahua; Zhao, Jialong; Li, Haibo

    2015-04-29

    Novel white light emitting diodes (LEDs) with environmentally friendly dual emissive quantum dots (QDs) as single color-converters are one of the most promising high-quality solid-state lighting sources for meeting the growing global demand for resource sustainability. A facile method was developed for the synthesis of the bright green-red-emitting Mn and Cu codoped Zn-In-S QDs with an absorption bangdgap of 2.56 eV (485 nm), a large Stokes shift of 150 nm, and high emission quantum yield up to 75%, which were suitable for warm white LEDs based on blue GaN chips. The wide photoluminescence (PL) spectra composed of Cu-related green and Mn-related red emissions in the codoped QDs could be controlled by varying the doping concentrations of Mn and Cu ions. The energy transfer processes in Mn and Cu codoped QDs were proposed on the basis of the changes in PL intensity and lifetime measured by means of steady-state and time-resolved PL spectra. By integrating these bicolor QDs with commercial GaN-based blue LEDs, the as-fabricated tricolor white LEDs showed bright natural white light with a color rendering index of 95, luminous efficacy of 73.2 lm/W, and color temperature of 5092 K. These results indicated that (Mn,Cu):Zn-In-S/ZnS QDs could be used as a single color-converting material for the next generation of solid-state lighting.

  14. Freely-Available, True-Color Volume Rendering Software and Cyro-Histology Datasets for Virtual Exploration the Temporal Bone Anatomy

    PubMed Central

    Kahrs, Lueder Alexander; Labadie, Robert Frederick

    2013-01-01

    Background Cadaveric dissection of temporal bone anatomy is not always possible or feasible in certain educational environments. Volume rendering using CT and/or MRI helps understanding of spatial relationships, but they suffer in non-realistic depictions especially regarding color of anatomical structures. Freely-available, non-stained histological datasets and software which are able to render such datasets in realistic color could overcome this limitation and be a very effective teaching tool. Methods With recent availability of specialized public-domain software, volume rendering of true-color, histological datasets is now possible. We present both feasibility as well as step-by-step instructions to allow processing of publically-available datasets (Visible Female Human and Visible Ear) into easily navigable three-dimensional models using free software. Results Example renderings are shown to demonstrate the utility of these free methods in virtual exploration of the complex anatomy of the temporal bone. After exploring the datasets, the Visible Ear appears more natural than the Visible Human. Conclusion We provide directions for an easy-to-use, open-source software in conjunction with freely available histological datasets. This work facilitates self-education of spatial relationships of anatomic structures inside the human temporal bone as well as allows exploration of surgical approaches prior to cadaveric testing and/or clinical implementation. PMID:23689270

  15. Color Index Imaging of the Stellar Stream Around NGC 5907

    NASA Astrophysics Data System (ADS)

    Laine, Seppo; Grillmair, Carl J.; Martinez-Delgado, David; Romanowsky, Aaron J.; Capak, Peter; Arendt, Richard G.; Ashby, Matthew; Davies, James E.; Majewski, Steven R.; GaBany, R. Jay

    2015-01-01

    We have obtained deep g, r, and i-band Subaru and ultra-deep 3.6 micron Spitzer/IRAC images of parts of the stellar stream around the nearby edge-on disk galaxy NGC 5907. We report on the color index distribution of the resolved emission along the stream, and indicators of recent star formation associated with the stream. We present scenarios regarding the nature of the disrupted satellite galaxy, based on our data. This work is based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. This work is based in part on data collected with the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. Support for this work was provided by NASA through an award issued by JPL/Caltech.

  16. Color Index Imaging of the Stellar Stream Around NGC 5907

    NASA Astrophysics Data System (ADS)

    Laine, Seppo; Grillmair, Carl J.; Martinez-Delgado, David; Romanowsky, Aaron; Capak, Peter; Arendt, Richard G.; Ashby, M. L. N.; Davies, James; Majewski, Steven; GaBany, R. Jay

    2015-08-01

    We have obtained deep g, r, and i-band Subaru and ultra-deep 3.6 micron Spitzer/IRAC images of parts of the spectacular, multiply-looped stellar stream around the nearby edge-on disk galaxy NGC 5907. We report on the color index distribution of the integrated starlight and the derived stellar populations along the stream. We present scenarios regarding the nature of the disrupted satellite galaxy, based on our data. This work is based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. This work is based in part on data collected with the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. Support for this work was provided by NASA through an award issued by JPL/Caltech.

  17. Glaucoma risk index: automated glaucoma detection from color fundus images.

    PubMed

    Bock, Rüdiger; Meier, Jörg; Nyúl, László G; Hornegger, Joachim; Michelson, Georg

    2010-06-01

    Glaucoma as a neurodegeneration of the optic nerve is one of the most common causes of blindness. Because revitalization of the degenerated nerve fibers of the optic nerve is impossible early detection of the disease is essential. This can be supported by a robust and automated mass-screening. We propose a novel automated glaucoma detection system that operates on inexpensive to acquire and widely used digital color fundus images. After a glaucoma specific preprocessing, different generic feature types are compressed by an appearance-based dimension reduction technique. Subsequently, a probabilistic two-stage classification scheme combines these features types to extract the novel Glaucoma Risk Index (GRI) that shows a reasonable glaucoma detection performance. On a sample set of 575 fundus images a classification accuracy of 80% has been achieved in a 5-fold cross-validation setup. The GRI gains a competitive area under ROC (AUC) of 88% compared to the established topography-based glaucoma probability score of scanning laser tomography with AUC of 87%. The proposed color fundus image-based GRI achieves a competitive and reliable detection performance on a low-priced modality by the statistical analysis of entire images of the optic nerve head.

  18. One-Step Preparation of Blue-Emitting (La,Ca)Si3(O,N)5:Ce3+ Phosphors for High-Color Rendering White Light-Emitting Diodes

    NASA Astrophysics Data System (ADS)

    Yaguchi, Atsuro; Suehiro, Takayuki; Sato, Tsugio; Hirosaki, Naoto

    2011-02-01

    Highly phase-pure (La,Ca)Si3(O,N)5:Ce3+ blue-emitting phosphors were successfully synthesized via the one-step solid-state reaction from the system La2O3-CaO-CeO2-Si3N4. The synthesized (La,Ca)Si3(O,N)5:Ce3+ exhibits tunable blue broadband emission with the dominant wavelength of 466-479 nm and the external quantum efficiency up to ˜45% under 380 nm near-UV (NUV) excitation. Spectral simulations of the trichromatic white light-emitting diodes (LEDs) using (La,Ca)Si3(O,N)5:Ce3+ demonstrated markedly higher color rendering index Ra values of 93-95, compared to 76-90 attained by the systems using a conventional BAM:Eu2+ phosphor or InGaN blue LED. The present achievement indicates the promising applicability of (La,Ca)Si3(O,N)5:Ce3+ as a blue luminescent source for NUV-converting high-color rendering white LEDs.

  19. Parallel rendering

    NASA Technical Reports Server (NTRS)

    Crockett, Thomas W.

    1995-01-01

    This article provides a broad introduction to the subject of parallel rendering, encompassing both hardware and software systems. The focus is on the underlying concepts and the issues which arise in the design of parallel rendering algorithms and systems. We examine the different types of parallelism and how they can be applied in rendering applications. Concepts from parallel computing, such as data decomposition, task granularity, scalability, and load balancing, are considered in relation to the rendering problem. We also explore concepts from computer graphics, such as coherence and projection, which have a significant impact on the structure of parallel rendering algorithms. Our survey covers a number of practical considerations as well, including the choice of architectural platform, communication and memory requirements, and the problem of image assembly and display. We illustrate the discussion with numerous examples from the parallel rendering literature, representing most of the principal rendering methods currently used in computer graphics.

  20. Evaluation of the effectiveness of color attributes for video indexing

    NASA Astrophysics Data System (ADS)

    Chupeau, Bertrand; Forest, Ronan

    2000-12-01

    Color features are reviewed and their effectiveness assessed in the application framework of key-frame clustering for abstracting unconstrained video. Existing color spaces and associated quantization schemes are first studied. Description of global color distribution by means of histograms is then detailed. In our work, twelve combinations of color space and quantization were selected, together with twelve histogram metrics. Their respective effectiveness with respect to picture similarity measurement was evaluated through a query-be-example scenario. For that purpose, a set of still-picture databases was built by extracting key-frames from several video clips, including news, documentaries, sports and cartoons. Classical retrieval performance evaluation criteria were adapted to the specificity of our testing methodology.

  1. Evaluation of the effectiveness of color attributes for video indexing

    NASA Astrophysics Data System (ADS)

    Chupeau, Bertrand; Forest, Ronan

    2001-01-01

    Color features are reviewed and their effectiveness assessed in the application framework of key-frame clustering for abstracting unconstrained video. Existing color spaces and associated quantization schemes are first studied. Description of global color distribution by means of histograms is then detailed. In our work, twelve combinations of color space and quantization were selected, together with twelve histogram metrics. Their respective effectiveness with respect to picture similarity measurement was evaluated through a query-be-example scenario. For that purpose, a set of still-picture databases was built by extracting key-frames from several video clips, including news, documentaries, sports and cartoons. Classical retrieval performance evaluation criteria were adapted to the specificity of our testing methodology.

  2. Evaluation of the effectiveness of color attributes for video indexing

    NASA Astrophysics Data System (ADS)

    Chupeau, Bertrand; Forest, Ronan

    2001-10-01

    Color features are reviewed and their effectiveness assessed in the application framework of key-frame clustering for abstracting unconstrained video. Existing color spaces and associated quantization schemes are first studied. Description of global color distribution by means of histograms is then detailed. In our work, 12 combinations of color space and quantization were selected, together with 12 histogram metrics. Their respective effectiveness with respect to picture similarity measurement was evaluated through a query-by-example scenario. For that purpose, a set of still-picture databases was built by extracting key frames from several video clips, including news, documentaries, sports and cartoons. Classical retrieval performance evaluation criteria were adapted to the specificity of our testing methodology.

  3. SRTM Data Release for Eurasia, Index Map and Colored Height

    NASA Technical Reports Server (NTRS)

    2004-01-01

    , various landforms place constraints upon land use planning for a great population. Volcanoes in the East Indies, the Philippines, Japan, and the Kamchatka Peninsula form the western part of the 'Ring of Fire' around the Pacific Ocean.

    Many of these regions were previously very poorly mapped due to persistent cloud cover or the inaccessibility of the terrain. Digital elevation data, such as provided by SRTM, are particularly in high demand by scientists studying earthquakes, volcanism, and erosion patterns for use in mapping and modeling hazards to human habitation. But the shape of Earth's surface affects nearly every natural process and human endeavor that occurs there, so elevation data are used in a wide range of applications.

    In this index map color-coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations. The large, very dark green feature in western Asia is the Caspian Sea, which is below sea level. Blue areas on the map represent water within the mapped tiles, each of which includes shorelines or islands.

    Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion

  4. The site occupation and valence of Mn ions in the crystal lattice of Sr{sub 4}Al{sub 14}O{sub 25} and its deep red emission for high color-rendering white light-emitting diodes

    SciTech Connect

    Chen, Lei; Xue, Shaochan; Chen, Xiuling; Bahader, Ali; Deng, Xiaorong; Zhao, Erlong; Jiang, Yang; Chen, Shifu; Chan, Ting-Shan; Zhao, Zhi; Zhang, Wenhua

    2014-12-15

    Highlights: • Different valences of Mn ions in Sr{sub 4}Al{sub 14}O{sub 25} were identified using XANES and EPR. • Red luminescence was attributed to Mn{sup 4+} occupying the center of AlO{sub 6} octahedron. • The Mn{sup 3+} incorporated in the center of AlO{sub 4} tetrahedron was non-luminescent. • The bond-valence theory was used to analyze the effective valences of cations. • A white LED device with CRI up to Ra 93.23 was packaged by using the red phosphor. - Abstract: The synthesis and component of red phosphor, Sr{sub 4}Al{sub 14}O{sub 25}: Mn, were optimized for application in white light-emitting diodes. The microstructure and morphology were investigated by the X-ray diffraction and scanning electron microscopy. Different valences of Mn ions in Sr{sub 4}Al{sub 14}O{sub 25} were discriminated using the electron paramagnetic resonance and X-ray absorption near-edge structure spectroscopy techniques. The bond-valence theory was used to analyze the effective valences of Sr{sup 2+} and Al{sup 3+} in Sr{sub 4}Al{sub 14}O{sub 25}. As a result, the strong covalence of Al{sup 3+} in the AlO{sub 4} tetrahedron other than in the AlO{sub 6} octahedron is disclosed. The deep red emission is attributed to Mn{sup 4+} occupying the center of AlO{sub 6} octahedron. The mechanism of energy transfer is mainly through dipole–dipole interaction, revealed by the analyses of critical distance and concentration quench. A high color rendering white LED prototype with color-rendering index up to Ra 93.23 packaged by using the red phosphor demonstrates its applicability.

  5. SRTM Data Release for Eurasia, Index Map and Colored Height

    NASA Technical Reports Server (NTRS)

    2004-01-01

    , various landforms place constraints upon land use planning for a great population. Volcanoes in the East Indies, the Philippines, Japan, and the Kamchatka Peninsula form the western part of the 'Ring of Fire' around the Pacific Ocean.

    Many of these regions were previously very poorly mapped due to persistent cloud cover or the inaccessibility of the terrain. Digital elevation data, such as provided by SRTM, are particularly in high demand by scientists studying earthquakes, volcanism, and erosion patterns for use in mapping and modeling hazards to human habitation. But the shape of Earth's surface affects nearly every natural process and human endeavor that occurs there, so elevation data are used in a wide range of applications.

    In this index map color-coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations. The large, very dark green feature in western Asia is the Caspian Sea, which is below sea level. Blue areas on the map represent water within the mapped tiles, each of which includes shorelines or islands.

    Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion

  6. Color generation and refractive index sensing using diffraction from 2D silicon nanowire arrays.

    PubMed

    Walia, Jaspreet; Dhindsa, Navneet; Khorasaninejad, Mohammadreza; Saini, Simarjeet Singh

    2014-01-15

    Tunable structural color generation from vertical silicon nanowires arranged in different square lattices is demonstrated. The generated colors are adjustable using well-defined Bragg diffraction theory, and only depend on the lattice spacing and angles of incidence. Vivid colors spanning from bright red to blue are easily achieved. In keeping with this, a single square lattice of silicon nanowires is also able to produce different colors spanning the entire visible range. It is also shown that the 2D gratings also have a third grating direction when rotated 45 degrees. These simple and elegant solutions to color generation from silicon are used to demonstrate a cost-effective refractive index sensor. The sensor works by measuring color changes resulting from changes in the refractive index of the medium surrounding the nanowires using a trichromatic RGB decomposition. Moreover, the sensor produces linear responses in the trichromatic decomposition values versus the surrounding medium index. An index resolution of 10(-4) is achieved by performing basic image processing on the collected images, without the need for a laser or a spectrometer. Spectral analysis enables an increase in the index resolution of the sensor to a value of 10(-6) , with a sensitivity of 400 nm/RIU. PMID:23784866

  7. Quantum rendering

    NASA Astrophysics Data System (ADS)

    Lanzagorta, Marco O.; Gomez, Richard B.; Uhlmann, Jeffrey K.

    2003-08-01

    In recent years, computer graphics has emerged as a critical component of the scientific and engineering process, and it is recognized as an important computer science research area. Computer graphics are extensively used for a variety of aerospace and defense training systems and by Hollywood's special effects companies. All these applications require the computer graphics systems to produce high quality renderings of extremely large data sets in short periods of time. Much research has been done in "classical computing" toward the development of efficient methods and techniques to reduce the rendering time required for large datasets. Quantum Computing's unique algorithmic features offer the possibility of speeding up some of the known rendering algorithms currently used in computer graphics. In this paper we discuss possible implementations of quantum rendering algorithms. In particular, we concentrate on the implementation of Grover's quantum search algorithm for Z-buffering, ray-tracing, radiosity, and scene management techniques. We also compare the theoretical performance between the classical and quantum versions of the algorithms.

  8. Quaternion structural similarity: a new quality index for color images.

    PubMed

    Kolaman, Amir; Yadid-Pecht, Orly

    2012-04-01

    One of the most important issues for researchers developing image processing algorithms is image quality. Methodical quality evaluation, by showing images to several human observers, is slow, expensive, and highly subjective. On the other hand, a visual quality matrix (VQM) is a fast, cheap, and objective tool for evaluating image quality. Although most VQMs are good in predicting the quality of an image degraded by a single degradation, they poorly perform for a combination of two degradations. An example for such degradation is the color crosstalk (CTK) effect, which introduces blur with desaturation. CTK is expected to become a bigger issue in image quality as the industry moves toward smaller sensors. In this paper, we will develop a VQM that will be able to better evaluate the quality of an image degraded by a combined blur/desaturation degradation and perform as well as other VQMs on single degradations such as blur, compression, and noise. We show why standard scalar techniques are insufficient to measure a combined blur/desaturation degradation and explain why a vectorial approach is better suited. We introduce quaternion image processing (QIP), which is a true vectorial approach and has many uses in the fields of physics and engineering. Our new VQM is a vectorial expansion of structure similarity using QIP, which gave it its name-Quaternion Structural SIMilarity (QSSIM). We built a new database of a combined blur/desaturation degradation and conducted a quality survey with human subjects. An extensive comparison between QSSIM and other VQMs on several image quality databases-including our new database-shows the superiority of this new approach in predicting visual quality of color images.

  9. a New Red Phosphor of the Mn Activated Non-Stoichiometric Strontium Aluminate 3SrO•5Al2O3 for High Color Rendering White Leds

    NASA Astrophysics Data System (ADS)

    Chen, Lei; Zhang, Yao; Liu, Fayong; Deng, Xiaorong; Xue, Shaochan; Luo, Anqi; Jiang, Yang; Chen, Shifu; Zhang, Wenhua

    2013-06-01

    A new red phosphor of strontium aluminate activated by Mn4+ was developed for high color rendering and warm white light-emitting diodes. The phosphor composition and conditions for synthesis were optimized through solid-state reaction. Meanwhile, the structure and morphology were investigated with XRD and SEM analysis. The results show that the 3SrO•5Al2O3 activated by 0.0005 M Mn fired at 1300°C in air ambient by adopting 2.5 wt.% AlF3 as flux exhibits most efficient luminescence. A white LED device prototype with CIE (0.3291, 0.3571), CCT 5639 K, CRI Ra 92.6, and efficacy 63 lm/W driven at 20 mA has been packaged by pre-coating the red phosphor combined with a yellow one Y3Al5O12:Ce3+ on a blue InGaN chip. The analysis of critical distance and luminescence quench reveal that the mechanism of energy transfer for luminescence is through dipole-dipole interaction.

  10. Antireflection-enhanced color by a natural graded refractive index (GRIN) structure.

    PubMed

    Eliason, Chad M; Shawkey, Matthew D

    2014-05-01

    Nanostructured materials like graded refractive index (GRIN) structures in moth eyes have inspired the design of novel antireflective coatings. Such structures are more flexible than uniform coatings, but applications have been mainly limited to broadband antireflection in solar cells and LEDs. Here we show that cylindrical pigment granules in two bird species (Polyplectron bicalcaratum and Patagioenas fasciata) form a GRIN that suppresses interference and expands the range of colors produced by a multilayer. These results demonstrate that a GRIN structure can function like a pigment (i.e. through selective, independent wavelength blocking) to generate unique colors and may inspire the design of novel antireflective and structurally colored coatings.

  11. Standing-wave resonances in plasmonic nanoumbrella cavities for color generation and colorimetric refractive index sensor

    NASA Astrophysics Data System (ADS)

    Fan, Jiaorong; Li, Zhongyuan; Chen, Zhuojie; Wu, Wengang

    2016-10-01

    We theoretically investigate the hybridization of the elemental surface plasmons in umbrella-shape plasmonic nanostructures and experimentally demonstrate the implementation of plasmonic multicolor metasurfaces as well as their application in colorimetric sensing. The three-dimension metallic umbrella arrays consist of a periodic canopy-capped-nanopillars with metal-coated sidewall and a backplane metal-film to form vertical nanocavity of canopy and film. Plasmonic coupling and energy confinement in nanocavity induce a noticeably resonance narrowing of multispectral reflection. The metasurfaced nanostructures appeared in vibrant and tunable colors with broad gamut derived from color blending mechanism due to multiple, narrow-band resonances. Vivid colors varied from red, yellow, green, blue to violet are easily achieved. It is also shown that such plasmonic metasurfaces can work as the feasible and real-time colorimetric refractive index sensor by measuring the distinct color variation to glucose concentration changes. Our sensor scheme shows its spectral sensitivity in the periodic umbrella array with respect to the refractive index change to be 242.5 nm/RIU with a figure of merit of 7.3. Furthermore, a refractive index resolution of colorimetric sensing up to 0.025 RIU has been accomplished.

  12. Index theorem and Majorana zero modes along a non-Abelian vortex in a color superconductor

    SciTech Connect

    Fujiwara, Takanori; Fukui, Takahiro; Nitta, Muneto; Yasui, Shigehiro

    2011-10-01

    Color superconductivity in high-density QCD exhibits the color-flavor-locked phase. To explore zero modes in the color-flavor-locked phase in the presence of a non-Abelian vortex with an SU(2) symmetry in the vortex core, we apply the index theorem to the Bogoliubov-de Gennes (BdG) Hamiltonian. From the calculation of the topological index, we find that triplet, doublet and singlet sectors of SU(2) have certain number of chiral Majorana zero modes in the limit of vanishing chemical potential. We also solve the BdG equation by the use of the series expansion to show that the number of zero modes and their chirality match the result of the index theorem. From particle-hole symmetry of the BdG Hamiltonian, we conclude that if and only if the index of a given sector is odd, one zero mode survives generically for a finite chemical potential. We argue that this result should hold nonperturbatively even in the high-density limit.

  13. Disentangling Effective Temperatures of Individual Eclipsing Binary Components by Means of Color-Index Constraining

    NASA Astrophysics Data System (ADS)

    Prša, A.; Zwitter, T.

    2006-08-01

    Eclipsing binary stars are gratifying objects because of their unique geometrical properties upon which all important physical parameters such as masses, radii, temperatures, luminosities and distance may be obtained in absolute scale. This poses strict demand on the model to be free of systematic effects that would influence the results later used for calibrations, catalogs and evolution theory. We present an objective scheme of obtaining individual temperatures of both binary system components by means of color-index constraining, with the only requirement that the observational data-set is acquired in a standard photometric system. We show that for a modest case of two similar main-sequence components the erroneous approach of assuming the temperature of the primary star from the color index yields temperatures which are systematically wrong by ˜ 100K.

  14. Measuring color quality of light sources

    NASA Astrophysics Data System (ADS)

    Davis, Wendy

    2006-08-01

    The successful commercialization of solid-state lighting for general illumination will require an effective method to characterize the color quality of these sources. The distinctive spectral characteristics of solid-state lighting sources present both unique challenges and opportunities with regards to color quality. Color quality is difficult to define, much less measure. Several aspects of color quality, including color fidelity (rendering), chromatic discrimination, and general population preferences must be considered. In some instances, these factors are contradictory. For example, observers tend to prefer lamps that increase object color chroma (vividness), though such chroma increases are deviations from color fidelity. In addition to devising a way to balance the influence of these different dimensions of color quality, consideration must be given to ways of communicating color quality in a simple way, which permits comparison between products. At NIST we're approaching this problem by developing a computational method that takes inspiration from the Color Rendering Index (CRI), but incorporates other aspects of color quality. The output of this Color Quality Scale (CQS) is a composite score incorporating a lamp's ability to accurately render object colors, permit precise discrimination between different colors, and display object colors in a way that is visually pleasing to typical consumers. Visual experimentation will be vital to improve and validate this method, which was initially developed with colorimetric simulations. Preliminary experimentation has begun, focusing on the issues most relevant to the development of commercial standards for color quality.

  15. Spectral reflectance of conodonts: A step toward quantitative color alteration and thermal maturity indexes

    SciTech Connect

    Deaton, B.C.; Nestell, M.; Balsam, W.L.

    1996-07-01

    Changes in the color of conodonts have long been used to assess thermal maturity. Color is a subjective measure, and color changes in conodonts are related to a subjective scale, the conodont alteration index or CAI. In this paper, we propose a simple, nondestructive method for objectively determining CAI and relating CAI to thermal maturity, the spectral reflectance of conodonts (SRC). The diffuse reflectance of about 30 large conodont fragments arranged on a barium-sulfate slide was determined with a total reflectance spectrophotometer in the wavelength range of 300-850 nm. By examining conodonts that ranged form a CAI of 1 to a CAI of 6 we found that the average slope of the reflectance curve from 550 to 800 nm is a good proxy for CAI. A second-order regression equation estimates CAI from this slope with high accuracy (correlation coefficient = 0.99). These estimates appear most accurate for a CAI of 1 to a CAI of 4, where the slopes change most rapidly, but give reasonable results up to a CAI of 6. Based on the results of our analysis of two samples with known thermal maturities form the Valles Caldera region of New Mexico, we propose a preliminary relationship among SRC slope, CAI, and in-situ alteration temperature.

  16. NONLINEAR COLOR-METALLICITY RELATIONS OF GLOBULAR CLUSTERS. V. NONLINEAR ABSORPTION-LINE INDEX VERSUS METALLICITY RELATIONS AND BIMODAL INDEX DISTRIBUTIONS OF M31 GLOBULAR CLUSTERS

    SciTech Connect

    Kim, Sooyoung; Yoon, Suk-Jin; Chung, Chul; Lee, Young-Wook; Caldwell, Nelson; Schiavon, Ricardo P.; Kang, Yongbeom; Rey, Soo-Chang

    2013-05-10

    Recent spectroscopy on the globular cluster (GC) system of M31 with unprecedented precision witnessed a clear bimodality in absorption-line index distributions of old GCs. Such division of extragalactic GCs, so far asserted mainly by photometric color bimodality, has been viewed as the presence of merely two distinct metallicity subgroups within individual galaxies and forms a critical backbone of various galaxy formation theories. Given that spectroscopy is a more detailed probe into stellar population than photometry, the discovery of index bimodality may point to the very existence of dual GC populations. However, here we show that the observed spectroscopic dichotomy of M31 GCs emerges due to the nonlinear nature of metallicity-to-index conversion and thus one does not necessarily have to invoke two separate GC subsystems. We take this as a close analogy to the recent view that metallicity-color nonlinearity is primarily responsible for observed GC color bimodality. We also demonstrate that the metallicity-sensitive magnesium line displays non-negligible metallicity-index nonlinearity and Balmer lines show rather strong nonlinearity. This gives rise to bimodal index distributions, which are routinely interpreted as bimodal metallicity distributions, not considering metallicity-index nonlinearity. Our findings give a new insight into the constitution of M31's GC system, which could change much of the current thought on the formation of GC systems and their host galaxies.

  17. Color

    ERIC Educational Resources Information Center

    Bowman, Bruce

    1975-01-01

    The color wheel, because it is an excellent way to teach color theory has become somewhat of a traditional assignment in most basic design courses. Article described a way to change this situation by re-designing and improving upon the basic color wheel. (Author/RK)

  18. Optical spectrum, perceived color, refractive index, and non-adiabatic dynamics of the photochromic diarylethene CMTE.

    PubMed

    Wiebeler, Christian; Bader, Christina A; Meier, Cedrik; Schumacher, Stefan

    2014-07-28

    Photochromism allows for reversible light-induced conversion of a molecular species into a different form with significantly altered optical properties. One promising compound that excels with high fatigue resistance and shows its photochromic functionality both in solution and in molecular solid films is the diarylethene derivative CMTE. Here we present a comprehensive study of its photophysical properties with density-functional theory based methods and benchmark the results against higher-level quantum-chemical approaches and experiments. In addition to static properties such as optical absorption, perceived color, and refractive index, we also investigate reaction dynamics based on non-adiabatic ab initio molecular dynamics. This gives detailed insight into the molecules' ultrafast reaction dynamics and enables us to extract reaction time scales and quantum yields for the observed electrocyclic reaction following photoexcitation.

  19. High quantum-yield CdSexS1-x/ZnS core/shell quantum dots for warm white light-emitting diodes with good color rendering

    NASA Astrophysics Data System (ADS)

    Duan, Hongyan; Jiang, Yang; Zhang, Yugang; Sun, Dapeng; Liu, Chao; Huang, Jian; Lan, Xinzheng; Zhou, Hongyang; Chen, Lei; Zhong, Honghai

    2013-07-01

    Composition-controllable ternary CdSexS1-x quantum dots (QDs) with multiple emission colors were obtained via a hot-injection-like method at a relatively low injection temperature (230 ° C) in octadecene. Then highly fluorescent CdSexS1-x/ZnS core/shell (CS) QDs were synthesized by a facile single-molecular precursor approach. The fluorescent quantum yield of the resulting green (λem = 523 nm), yellow (λem = 565 nm) and red (λem = 621 nm) emission of CS QDs in toluene reached up to 85%, 55% and 39%, respectively. Moreover, a QDs white light-emitting diode (QDs-WLED) was fabricated by hybridizing green-, yellow- and red-emitting CdSexS1-x/ZnS CS QDs/epoxy composites on a blue InGaN chip. The resulting four-band RYGB QDs-WLED showed good performance with CIE-1931 coordinates of (0.4137, 0.3955), an Ra of 81, and a Tc of 3360 K at 30 mA, which indicated the combination of multiple-color QDs with high fluorescence QYs in LEDs as a promising approach to obtain warm WLEDs with good color rendering.

  20. High-throughput flow injection analysis mass spectroscopy with networked delivery of color-rendered results. 2. Three-dimensional spectral mapping of 96-well combinatorial chemistry racks.

    PubMed

    Görlach, E; Richmond, R; Lewis, I

    1998-08-01

    For the last two years, the mass spectroscopy section of the Novartis Pharma Research Core Technology group has analyzed tens of thousands of multiple parallel synthesis samples from the Novartis Pharma Combinatorial Chemistry program, using an in-house developed automated high-throughput flow injection analysis electrospray ionization mass spectroscopy system. The electrospray spectra of these samples reflect the many structures present after the cleavage step from the solid support. The overall success of the sequential synthesis is mirrored in the purity of the expected end product, but the partial success of individual synthesis steps is evident in the impurities in the mass spectrum. However this latter reaction information, which is of considerable utility to the combinatorial chemist, is effectively hidden from view by the very large number of analyzed samples. This information is now revealed at the workbench of the combinatorial chemist by a novel three-dimensional display of each rack's complete mass spectral ion current using the in-house RackViewer Visual Basic application. Colorization of "forbidden loss" and "forbidden gas-adduct" zones, normalization to expected monoisotopic molecular weight, colorization of ionization intensity, and sorting by row or column were used in combination to highlight systematic patterns in the mass spectroscopy data.

  1. [Research on developping the spectral dataset for Dunhuang typical colors based on color constancy].

    PubMed

    Liu, Qiang; Wan, Xiao-Xia; Liu, Zhen; Li, Chan; Liang, Jin-Xing

    2013-11-01

    The present paper aims at developping a method to reasonably set up the typical spectral color dataset for different kinds of Chinese cultural heritage in color rendering process. The world famous wall paintings dating from more than 1700 years ago in Dunhuang Mogao Grottoes was taken as typical case in this research. In order to maintain the color constancy during the color rendering workflow of Dunhuang culture relics, a chromatic adaptation based method for developping the spectral dataset of typical colors for those wall paintings was proposed from the view point of human vision perception ability. Under the help and guidance of researchers in the art-research institution and protection-research institution of Dunhuang Academy and according to the existing research achievement of Dunhuang Research in the past years, 48 typical known Dunhuang pigments were chosen and 240 representative color samples were made with reflective spectral ranging from 360 to 750 nm was acquired by a spectrometer. In order to find the typical colors of the above mentioned color samples, the original dataset was devided into several subgroups by clustering analysis. The grouping number, together with the most typical samples for each subgroup which made up the firstly built typical color dataset, was determined by wilcoxon signed rank test according to the color inconstancy index comprehensively calculated under 6 typical illuminating conditions. Considering the completeness of gamut of Dunhuang wall paintings, 8 complementary colors was determined and finally the typical spectral color dataset was built up which contains 100 representative spectral colors. The analytical calculating results show that the median color inconstancy index of the built dataset in 99% confidence level by wilcoxon signed rank test was 3.28 and the 100 colors are distributing in the whole gamut uniformly, which ensures that this dataset can provide reasonable reference for choosing the color with highest

  2. Space weathering and the color indexes of minor bodies in the outer Solar System

    NASA Astrophysics Data System (ADS)

    Kaňuchová, Z.; Brunetto, R.; Melita, M.; Strazzulla, G.

    2012-09-01

    We present a model based on laboratory results which contributes to the "nature" versus "nurture" debate on the colors of small bodies in the outer Solar System (OSS). According to our model, objects having suffered the same balance of irradiation and impacts follow specific curves in color-color diagrams. Appropriate combination of composition and weathering can reproduce the whole range of colors observed on OSS small bodies

  3. Conodont color alteration index and upper Paleozoic thermal history of the Amazonas Basin, Brazil

    NASA Astrophysics Data System (ADS)

    Cardoso, Cassiane Negreiros; Sanz-López, Javier; Blanco-Ferrera, Silvia; Lemos, Valesca Brasil; Scomazzon, Ana Karina

    2015-12-01

    The conodont color alteration index (CAI) was determined in elements from core samples of the Frasnian Barreirinha Formation (one well) and of the Pennsylvanian-Permian Tapajós Group (twenty three wells and one limestone quarry) in the Amazonas Basin. The thermal history of the basin is analyzed using the CAI value distribution represented in maps and stratigraphic sections through correlation schemes, and in conjunction with previously published data. The pattern of palaeotemperatures for CAI values of 1.5-3 is coincident with organic matter maturation under a sedimentary overburden providing diagenetic conditions in the oil/gas window. Locally, conodonts show metamorphism (CAI value of 6-7) in relation to the intrusion of diabase bodies in beds including high geothermal gradient evaporites. Microtextural alteration on the surface conodonts commonly shows several types of overgrowth microtextures developed in diagenetic conditions. Locally, recrystallization in conodonts with a high CAI value is congruent with contact metamorphism in relation to Mesozoic intrusions. The CAI values of 1.5 or 2 observed close to the surface in several areas of the basin may be interpreted in relation to a high thermal palaeogradient derived from the magmatic episode or/and to the local denudation of the upper part of the Paleozoic succession prior to this thermal event.

  4. Parallel sphere rendering

    SciTech Connect

    Krogh, M.; Painter, J.; Hansen, C.

    1996-10-01

    Sphere rendering is an important method for visualizing molecular dynamics data. This paper presents a parallel algorithm that is almost 90 times faster than current graphics workstations. To render extremely large data sets and large images, the algorithm uses the MIMD features of the supercomputers to divide up the data, render independent partial images, and then finally composite the multiple partial images using an optimal method. The algorithm and performance results are presented for the CM-5 and the M.

  5. 10 CFR Appendix R to Subpart B of... - Uniform Test Method for Measuring Average Lamp Efficacy (LE), Color Rendering Index (CRI), and...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... lamp lumens, electrical characteristics, CRI, and CCT for general service fluorescent lamps, and to the... general service fluorescent lamps, in IESNA LM-20 for incandescent reflector lamps, in IESNA LM-45 for... Service Fluorescent Lamps: For general service fluorescent lamps, the ambient conditions of the test...

  6. 10 CFR Appendix R to Subpart B of... - Uniform Test Method for Measuring Average Lamp Efficacy (LE), Color Rendering Index (CRI), and...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... lamp lumens, electrical characteristics, CRI, and CCT for general service fluorescent lamps, and to the... service fluorescent lamps, in IESNA LM-20 for incandescent reflector lamps, and in IES LM-45 for general service incandescent lamps. 3. Test Conditions 3.1 General Service Fluorescent Lamps: For general...

  7. 10 CFR Appendix R to Subpart B of... - Uniform Test Method for Measuring Average Lamp Efficacy (LE), Color Rendering Index (CRI), and...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... lamp lumens, electrical characteristics, CRI, and CCT for general service fluorescent lamps, and to the... service fluorescent lamps, in IESNA LM-20 for incandescent reflector lamps, and in IES LM-45 for general service incandescent lamps. 3. Test Conditions 3.1General Service Fluorescent Lamps: For general...

  8. 10 CFR Appendix R to Subpart B of... - Uniform Test Method for Measuring Average Lamp Efficacy (LE), Color Rendering Index (CRI), and...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... lamp lumens, electrical characteristics, CRI, and CCT for general service fluorescent lamps, and to the... general service fluorescent lamps, in IESNA LM-20 for incandescent reflector lamps, in IESNA LM-45 for... Service Fluorescent Lamps: For general service fluorescent lamps, the ambient conditions of the test...

  9. 10 CFR Appendix R to Subpart B of... - Uniform Test Method for Measuring Average Lamp Efficacy (LE), Color Rendering Index (CRI), and...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... lamp lumens, electrical characteristics, CRI, and CCT for general service fluorescent lamps, and to the... general service fluorescent lamps, in IESNA LM-20 for incandescent reflector lamps, in IESNA LM-45 for... Service Fluorescent Lamps: For general service fluorescent lamps, the ambient conditions of the test...

  10. Parallel sphere rendering

    SciTech Connect

    Krogh, M.; Hansen, C.; Painter, J.; de Verdiere, G.C.

    1995-05-01

    Sphere rendering is an important method for visualizing molecular dynamics data. This paper presents a parallel divide-and-conquer algorithm that is almost 90 times faster than current graphics workstations. To render extremely large data sets and large images, the algorithm uses the MIMD features of the supercomputers to divide up the data, render independent partial images, and then finally composite the multiple partial images using an optimal method. The algorithm and performance results are presented for the CM-5 and the T3D.

  11. Space weathering and the color indexes of minor bodies in the outer Solar System

    NASA Astrophysics Data System (ADS)

    Kaňuchová, Zuzana; Brunetto, Rosario; Melita, Mario; Strazzulla, Giovanni

    2012-09-01

    The surfaces of small bodies in the outer Solar System are rich in organic compounds and carbonaceous refractories mixed with ices and silicates. As made clear by dedicated laboratory experiments space weathering (e.g. energetic ion bombardment) can produce red colored materials starting from bright and spectrally flat ices. In a classical scenario, the space weathering processes “nurture” alter the small bodies surface spectra but are in competition with resurfacing agents that restore the original colors, and the result of these competing processes continuously modifying the surfaces is supposed to be responsible for the observed spectral variety of those small bodies. However an alternative point of view is that the different colors are due to “nature” i.e. to the different primordial composition of different objects. In this paper we present a model, based on laboratory results, that gives an original contribution to the “nature” vs. “nurture” debate by addressing the case of surfaces showing different fractions of rejuvenated vs. space weathered surface, and calculating the corresponding color variations. We will show how a combination of increasing dose coupled to different resurfacing can reproduce the whole range of observations of small outer Solar System bodies. Here we demonstrate, for the first time that objects having a fully weathered material turn back in the color-color diagrams. At the same time, object with the different ratio of pristine and weathered surface areas lay on specific lines in color-color diagrams, if exposed to the same amount of irradiation.

  12. Lifetime Reduction and Enhanced Emission of Single Photon Color Centers in Nanodiamond via Surrounding Refractive Index Modification

    PubMed Central

    Khalid, Asma; Chung, Kelvin; Rajasekharan, Ranjith; Lau, Desmond W.M.; Karle, Timothy J.; Gibson, Brant C.; Tomljenovic-Hanic, Snjezana

    2015-01-01

    The negatively-charged nitrogen vacancy (NV−) center in diamond is of great interest for quantum information processing and quantum key distribution applications due to its highly desirable long coherence times at room temperature. One of the challenges for their use in these applications involves the requirement to further optimize the lifetime and emission properties of the centers. Our results demonstrate the reduction of the lifetime of NV− centers, and hence an increase in the emission rate, achieved by modifying the refractive index of the environment surrounding the nanodiamond (ND). By coating the NDs in a polymer film, experimental results and numerical calculations show an average of 63% reduction in the lifetime and an average enhancement in the emission rate by a factor of 1.6. This strategy is also applicable for emitters other than diamond color centers where the particle refractive index is greater than the refractive index of the surrounding media. PMID:26109500

  13. Lifetime Reduction and Enhanced Emission of Single Photon Color Centers in Nanodiamond via Surrounding Refractive Index Modification

    NASA Astrophysics Data System (ADS)

    Khalid, Asma; Chung, Kelvin; Rajasekharan, Ranjith; Lau, Desmond W. M.; Karle, Timothy J.; Gibson, Brant C.; Tomljenovic-Hanic, Snjezana

    2015-06-01

    The negatively-charged nitrogen vacancy (NV-) center in diamond is of great interest for quantum information processing and quantum key distribution applications due to its highly desirable long coherence times at room temperature. One of the challenges for their use in these applications involves the requirement to further optimize the lifetime and emission properties of the centers. Our results demonstrate the reduction of the lifetime of NV- centers, and hence an increase in the emission rate, achieved by modifying the refractive index of the environment surrounding the nanodiamond (ND). By coating the NDs in a polymer film, experimental results and numerical calculations show an average of 63% reduction in the lifetime and an average enhancement in the emission rate by a factor of 1.6. This strategy is also applicable for emitters other than diamond color centers where the particle refractive index is greater than the refractive index of the surrounding media.

  14. North Atlantic Plio-Pliestocene sediment color climate index indicates enhanced 41-k.y. world variability

    NASA Astrophysics Data System (ADS)

    Obrochta, Stephen; Bailey, Ian; Channell, James; Hodell, David; Timmermann, Axel; Tyler, Jonathan; Xuan, Chuang; Yokoyama, Yusuke

    2016-04-01

    Sediment color variations at North Atlantic Site DSDP609/U1308 exhibit a very similar pattern to the water isotope record of the North GRIP ice core. Moving window cross correlation between NGRIP oxygen isotopes and sediment lightness (L*) reveals a consistently high and significant correlation. Based on this relationship, we construct a color-based climate index by calculating color reflectance values from the shipboard line-scanner images. Use of the line-scanner images provides a higher-resolution series (0.01 cm) than the 2-cm shipboard spectrophotometer data and permits for manual removal of disturbed pixels prior to analysis. At present, the composite benthic oxygen isotope and paleomagnetic records at Site U1308 extend to MIS K2, providing age control beyond 3 Ma. The same approach at a more northerly location (IODP Site U1304) yields very similar results, in terms of event pattern, timing, and duration, over the past few glacial cycles, suggesting the much longer Site U1308 record likely reflects conditions over a relatively large spatial area. Rapidity of color variations decreases following the onset of the large amplitude 100-k.y. glaciations. Both Sites U1304 and U1308 exhibit near identical color changes during the penultimate glaciation (MIS 6), which is characterized by fluctuations that are among the most gradual of the entire ~3 Ma record. With the exception of MIS 6, results generally agree with the synthetic Greenland isotope record. Orbital scale color variations are near synchronous with benthic oxygen isotopes at a 41 k.y. period but lag significantly at 100 k.y.

  15. Notes on the application of the standardized residual sum of squares index for the assessment of intra- and inter-observer variability in color-difference experiments.

    PubMed

    Melgosa, Manuel; García, Pedro A; Gómez-Robledo, Luis; Shamey, Renzo; Hinks, David; Cui, Guihua; Luo, M Ronnier

    2011-05-01

    The standardized residual sum of squares index was proposed to examine the significant merit of a given color-difference formula over another with respect to a given set of visual color-difference data [J. Opt. Soc. Am. A 24, 1823-1829, 2007]. This index can also be employed to determine intra- and inter-observer variability, although the full complexity of this variability cannot be described by just one number. Appropriate utilization of the standardized residual sum of squares index for the assessment of observer variability is described with a view to encourage its use in future color-difference research. The main goal of this paper is to demonstrate that setting the F parameters of the standardized residual sum of squares index to 1 results in a loss of essential properties of the index (for example, symmetry), and is therefore strongly discouraged. PMID:21532709

  16. Integration of Color and Local Derivative Pattern Features for Content-Based Image Indexing and Retrieval

    NASA Astrophysics Data System (ADS)

    Vipparthi, Santosh Kumar; Nagar, Shyam Krishna

    2015-09-01

    This paper presents two new feature descriptors for content based image retrieval (CBIR) application. The proposed two descriptors are named as color local derivative patterns (CLDP) and inter color local derivative pattern (ICLDP). In order to reduce the computational complexity the uniform patterns are applied to both CLDP and ICLDP. Further, uniform CLDP (CLDPu2) and uniform ICLDP (ICLDPu2) are generated respectively. The proposed descriptors are able to exploit individual (R, G and B) spectral channel information and co-relating pair (RG, GB, BR, etc.) of spectral channel information. The retrieval performances of the proposed descriptors (CLDP and ICLDP) are tested by conducting two experiments on Corel-5000 and Corel-10000 benchmark databases. The results after investigation show a significant improvement in terms of precision, average retrieval precision (ARP), recall and average retrieval rate (ARR) as compared to local binary patterns (LBP), local derivative patterns (LDP) and other state-of-the-art techniques for image retrieval.

  17. An automated technique for stellar magnitude, color index, and position measurements of astronomical photographs

    NASA Technical Reports Server (NTRS)

    Green, R. F.; Morrill, M. E.

    1978-01-01

    Computer programs have been developed for use in collecting and processing data from a PDS scanning microdensitometer. The goal is to obtain fast and simple algorithms for handling an entire astronomical photograph with one-pass digitization. This capability is realized by a real-time detection scheme that provides a data compression of a factor of 100, and a processing program that produces a catalog of magnitudes, color indices, and positions for up to 90,000 multicolor stellar images.

  18. A practical approach to spectral volume rendering.

    PubMed

    Bergner, Steven; Möller, Torsten; Tory, Melanie; Drew, Mark S

    2005-01-01

    To make a spectral representation of color practicable for volume rendering, a new low-dimensional subspace method is used to act as the carrier of spectral information. With that model, spectral light material interaction can be integrated into existing volume rendering methods at almost no penalty. In addition, slow rendering methods can profit from the new technique of postillumination-generating spectral images in real-time for arbitrary light spectra under a fixed viewpoint. Thus, the capability of spectral rendering to create distinct impressions of a scene under different lighting conditions is established as a method of real-time interaction. Although we use an achromatic opacity in our rendering, we show how spectral rendering permits different data set features to be emphasized or hidden as long as they have not been entirely obscured. The use of postillumination is an order of magnitude faster than changing the transfer function and repeating the projection step. To put the user in control of the spectral visualization, we devise a new widget, a "light-dial," for interactively changing the illumination and include a usability study of this new light space exploration tool. Applied to spectral transfer functions, different lights bring out or hide specific qualities of the data. In conjunction with postillumination, this provides a new means for preparing data for visualization and forms a new degree of freedom for guided exploration of volumetric data sets.

  19. Sorting and hardware assisted rendering for volume visualization

    SciTech Connect

    Stein, C.; Becker, B.; Max, N.

    1994-03-01

    We present some techniques for volume rendering unstructured data. Interpolation between vertex colors and opacities is performed using hardware assisted texture mapping, and color is integrated for use with a volume rendering system. We also present an O(n{sup 2}) method for sorting n arbitrarily shaped convex polyhedra prior to visualization. It generalizes the Newell, Newell and Sancha sort for polygons to 3-D volume elements.

  20. Comparative analysis of shell rendering and shear-warp rendering

    NASA Astrophysics Data System (ADS)

    Falcao, Alexandre X.; Rocha, Leonardo M.; Udupa, Jayaram K.

    2002-05-01

    In Medical Imaging, shell rendering and shear-warp rendering are two of the most efficient and effective voxel-based techniques for volume visualization. This work presents a comparative analysis of shell rendering and shear-warp rendering in terms of storage, speed, and image quality. We have chosen 10 different objects of various sizes, shapes and topologies and one 1-GHz Pentium-III PC with 512 MB RAM for our experiments. Hard and fuzzy boundaries of up to 2,833 K voxels in size have been created to test both methods in surface and volume rendering, respectively. Hard surface shell rendering and surface shear-warp rendering required less than 0.5 second. In the worst case, volume shell rendering required 1.45 second, while volume shear-warp rendering spent 0.65 second for the same task. Shear-warp rendering uses on average from 3 to 6 times more memory space than shell rendering, but it can be up to 2.79 times faster than shell rendering. On average, shear-warp rendering is as fast as shell rendering for hard boundaries and 1.7 times faster than shell rendering for fuzzy boundaries. We have also observed that both can produce similar high-quality images.

  1. Rendering the Topological Spines

    SciTech Connect

    Nieves-Rivera, D.

    2015-05-05

    Many tools to analyze and represent high dimensional data already exits yet most of them are not flexible, informative and intuitive enough to help the scientists make the corresponding analysis and predictions, understand the structure and complexity of scientific data, get a complete picture of it and explore a greater number of hypotheses. With this in mind, N-Dimensional Data Analysis and Visualization (ND²AV) is being developed to serve as an interactive visual analysis platform with the purpose of coupling together a number of these existing tools that range from statistics, machine learning, and data mining, with new techniques, in particular with new visualization approaches. My task is to create the rendering and implementation of a new concept called topological spines in order to extend ND²AV's scope. Other existing visualization tools create a representation preserving either the topological properties or the structural (geometric) ones because it is challenging to preserve them both simultaneously. Overcoming such challenge by creating a balance in between them, the topological spines are introduced as a new approach that aims to preserve them both. Its render using OpenGL and C++ and is currently being tested to further on be implemented on ND²AV. In this paper I will present what are the Topological Spines and how they are rendered.

  2. Rendered virtual view image objective quality assessment

    NASA Astrophysics Data System (ADS)

    Lu, Gang; Li, Xiangchun; Zhang, Yi; Peng, Kai

    2013-08-01

    The research on rendered virtual view image (RVVI) objective quality assessment is important for integrated imaging system and image quality assessment (IQA). Traditional IQA algorithms cannot be applied directly on the system receiver-side due to interview displacement and the absence of original reference. This study proposed a block-based neighbor reference (NbR) IQA framework for RVVI IQA. Neighbor views used for rendering are employed for quality assessment in the proposed framework. A symphonious factor handling noise and interview displacement is defined and applied to evaluate the contribution of the obtained quality index in each block pair. A three-stage experiment scheme is also presented to testify the proposed framework and evaluate its homogeneity performance when comparing to full reference IQA. Experimental results show the proposed framework is useful in RVVI objective quality assessment at system receiver-side and benchmarking different rendering algorithms.

  3. Software for Acoustic Rendering

    NASA Technical Reports Server (NTRS)

    Miller, Joel D.

    2003-01-01

    SLAB is a software system that can be run on a personal computer to simulate an acoustic environment in real time. SLAB was developed to enable computational experimentation in which one can exert low-level control over a variety of signal-processing parameters, related to spatialization, for conducting psychoacoustic studies. Among the parameters that can be manipulated are the number and position of reflections, the fidelity (that is, the number of taps in finite-impulse-response filters), the system latency, and the update rate of the filters. Another goal in the development of SLAB was to provide an inexpensive means of dynamic synthesis of virtual audio over headphones, without need for special-purpose signal-processing hardware. SLAB has a modular, object-oriented design that affords the flexibility and extensibility needed to accommodate a variety of computational experiments and signal-flow structures. SLAB s spatial renderer has a fixed signal-flow architecture corresponding to a set of parallel signal paths from each source to a listener. This fixed architecture can be regarded as a compromise that optimizes efficiency at the expense of complete flexibility. Such a compromise is necessary, given the design goal of enabling computational psychoacoustic experimentation on inexpensive personal computers.

  4. Sea modeling and rendering

    NASA Astrophysics Data System (ADS)

    Cathala, Thierry; Latger, Jean

    2010-10-01

    More and more defence and civil applications require simulation of marine synthetic environment. Currently, the "Future Anti-Surface-Guided-Weapon" (FASGW) or "anti-navire léger" (ANL) missile needs this kind of modelling. This paper presents a set of technical enhancement of the SE-Workbench that aim at better representing the sea profile and the interaction with targets. The operational scenario variability is a key criterion: the generic geographical area (e.g. Persian Gulf, coast of Somalia,...), the type of situation (e.g. peace keeping, peace enforcement, anti-piracy, drug interdiction,...)., the objectives (political, strategic, or military objectives), the description of the mission(s) (e.g. antipiracy) and operation(s) (e.g. surveillance and reconnaissance, escort, convoying) to achieve the objectives, the type of environment (Weather, Time of day, Geography [coastlines, islands, hills/mountains]). The paper insists on several points such as the dual rendering using either ray tracing [and the GP GPU optimization] or rasterization [and GPU shaders optimization], the modelling of sea-surface based on hypertextures and shaders, the wakes modelling, the buoyancy models for targets, the interaction of coast and littoral, the dielectric infrared modelling of water material.

  5. Parallel hierarchical radiosity rendering

    SciTech Connect

    Carter, M.

    1993-07-01

    In this dissertation, the step-by-step development of a scalable parallel hierarchical radiosity renderer is documented. First, a new look is taken at the traditional radiosity equation, and a new form is presented in which the matrix of linear system coefficients is transformed into a symmetric matrix, thereby simplifying the problem and enabling a new solution technique to be applied. Next, the state-of-the-art hierarchical radiosity methods are examined for their suitability to parallel implementation, and scalability. Significant enhancements are also discovered which both improve their theoretical foundations and improve the images they generate. The resultant hierarchical radiosity algorithm is then examined for sources of parallelism, and for an architectural mapping. Several architectural mappings are discussed. A few key algorithmic changes are suggested during the process of making the algorithm parallel. Next, the performance, efficiency, and scalability of the algorithm are analyzed. The dissertation closes with a discussion of several ideas which have the potential to further enhance the hierarchical radiosity method, or provide an entirely new forum for the application of hierarchical methods.

  6. Method and apparatus for enhanced evanescent fluorescence and color filtering using a high refractive index thin film coating

    DOEpatents

    Kao, Hung Pin; Schoeniger, Joseph; Yang, Nancy

    2001-01-01

    A technique for increasing the excitation and collection of evanescent fluorescence radiation emanating from a fiber optic sensor having a high refractive index (n.sub.r), dielectric thin film coating has been disclosed and described. The invention comprises a clad optical fiber core whose cladding is removed on a distal end, the distal end coated with a thin, non-porous, titanium dioxide sol-gel coating. It has been shown that such a fiber will exhibit increased fluorescence coupling due in part by 1) increasing the intensity of the evanescent field at the fiber core surface by a constructive interference effect on the propagating light, and 2) increasing the depth of penetration of the field in the sample. The interference effect created by the thin film imposes a wavelength dependence on the collection of the fluorescence and also suggests a novel application of thin films for color filtering as well as increasing collected fluorescence in fiber sensors. Collected fluorescence radiation increased by up to 6-fold over that of a bare fused silica fiber having a numerical aperture (N.A.) of O.6.

  7. Comparison of lower limb arterial assessments using color-duplex ultrasound and ankle/brachial pressure index measurements.

    PubMed

    Allen, J; Oates, C P; Henderson, J; Jago, J; Whittingham, T A; Chamberlain, J; Jones, N A; Murray, A

    1996-03-01

    The strength of agreement between two noninvasive methods of assessing lower limb arterial disease and their relationship to patient symptoms following exercise have been investigated. Color-duplex ultrasound (CDU) and ankle/brachial pressure index (ABPI) (before and afer exercise) measurements were obtained from 200 consecutive patients referred to a vascular investigations laboratory. From these patients, 290 limbs were available for study, comprising limbs without previous vascular surgery, from patients without diabetes and who could attempt a walking exercise test. The overall level of agreement between CDU and resting ABPI measurements was 83% (Kappa 0.66). The ABPI technique identified the more serious disease; a resting ABPI of less than 0.6 gave 100% agreement with CDU. With higher resting ABPIs the level of agreement became poorer: 83% (0.6 < or = ABPI <0.9) and 76% (normal ABPI > or = 0.9). The addition of postexercise ABPI measurements in determining significant arterial disease increased the strength of relationship between the two techniques by only 2% (85%, Kappa 0.69). The exercise test was generally limited by the most symptomatic limb in each patient, and the agreement between CDU and postexercise ABPI measurements in these limbs was higher at 93% (Kappa 0.81). In comparison, agreement for the least symptomatic group of limbs was found to be poor (69%, Kappa 0.37). Compared with symptoms after exercise, overall agreements with CDU and ABPI were both 67% (Kappa 0.27). The agreement was better (91%) when the resting ABPI was less than 0.6. The ABPI is biased toward the detection of more severe disease and is more consistent with CDU when the most symptomatic limbs are compared. The relationship between either test and symptoms after exercise is strong only for limbs with major disease.

  8. New Uses for Rendered Protein

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The history of rendering shows that current uses for rendered protein are a result of value-adding research. Feed nutritionists discovered how to use this formerly very low value by-product as an important component of formulated livestock feed. Today the feed market is mature and has been severel...

  9. Massively parallel visualization: Parallel rendering

    SciTech Connect

    Hansen, C.D.; Krogh, M.; White, W.

    1995-12-01

    This paper presents rendering algorithms, developed for massively parallel processors (MPPs), for polygonal, spheres, and volumetric data. The polygon algorithm uses a data parallel approach whereas the sphere and volume renderer use a MIMD approach. Implementations for these algorithms are presented for the Thinking Machines Corporation CM-5 MPP.

  10. Exposure Render: An Interactive Photo-Realistic Volume Rendering Framework

    PubMed Central

    Kroes, Thomas; Post, Frits H.; Botha, Charl P.

    2012-01-01

    The field of volume visualization has undergone rapid development during the past years, both due to advances in suitable computing hardware and due to the increasing availability of large volume datasets. Recent work has focused on increasing the visual realism in Direct Volume Rendering (DVR) by integrating a number of visually plausible but often effect-specific rendering techniques, for instance modeling of light occlusion and depth of field. Besides yielding more attractive renderings, especially the more realistic lighting has a positive effect on perceptual tasks. Although these new rendering techniques yield impressive results, they exhibit limitations in terms of their exibility and their performance. Monte Carlo ray tracing (MCRT), coupled with physically based light transport, is the de-facto standard for synthesizing highly realistic images in the graphics domain, although usually not from volumetric data. Due to the stochastic sampling of MCRT algorithms, numerous effects can be achieved in a relatively straight-forward fashion. For this reason, we have developed a practical framework that applies MCRT techniques also to direct volume rendering (DVR). With this work, we demonstrate that a host of realistic effects, including physically based lighting, can be simulated in a generic and flexible fashion, leading to interactive DVR with improved realism. In the hope that this improved approach to DVR will see more use in practice, we have made available our framework under a permissive open source license. PMID:22768292

  11. Exposure render: an interactive photo-realistic volume rendering framework.

    PubMed

    Kroes, Thomas; Post, Frits H; Botha, Charl P

    2012-01-01

    The field of volume visualization has undergone rapid development during the past years, both due to advances in suitable computing hardware and due to the increasing availability of large volume datasets. Recent work has focused on increasing the visual realism in Direct Volume Rendering (DVR) by integrating a number of visually plausible but often effect-specific rendering techniques, for instance modeling of light occlusion and depth of field. Besides yielding more attractive renderings, especially the more realistic lighting has a positive effect on perceptual tasks. Although these new rendering techniques yield impressive results, they exhibit limitations in terms of their exibility and their performance. Monte Carlo ray tracing (MCRT), coupled with physically based light transport, is the de-facto standard for synthesizing highly realistic images in the graphics domain, although usually not from volumetric data. Due to the stochastic sampling of MCRT algorithms, numerous effects can be achieved in a relatively straight-forward fashion. For this reason, we have developed a practical framework that applies MCRT techniques also to direct volume rendering (DVR). With this work, we demonstrate that a host of realistic effects, including physically based lighting, can be simulated in a generic and flexible fashion, leading to interactive DVR with improved realism. In the hope that this improved approach to DVR will see more use in practice, we have made available our framework under a permissive open source license.

  12. Scalable rendering on PC clusters

    SciTech Connect

    WYLIE,BRIAN N.; LEWIS,VASILY; SHIRLEY,DAVID NOYES; PAVLAKOS,CONSTANTINE

    2000-04-25

    This case study presents initial results from research targeted at the development of cost-effective scalable visualization and rendering technologies. The implementations of two 3D graphics libraries based on the popular sort-last and sort-middle parallel rendering techniques are discussed. An important goal of these implementations is to provide scalable rendering capability for extremely large datasets (>> 5 million polygons). Applications can use these libraries for either run-time visualization, by linking to an existing parallel simulation, or for traditional post-processing by linking to an interactive display program. The use of parallel, hardware-accelerated rendering on commodity hardware is leveraged to achieve high performance. Current performance results show that, using current hardware (a small 16-node cluster), they can utilize up to 85% of the aggregate graphics performance and achieve rendering rates in excess of 20 million polygons/second using OpenGL{reg_sign} with lighting, Gouraud shading, and individually specified triangles (not t-stripped).

  13. Rendering for machine vision prototyping

    NASA Astrophysics Data System (ADS)

    Reiner, Jacek

    2008-09-01

    Machine Vision systems for manufacturing quality inspection are interdisciplinary solutions including lighting, optics, cameras, image processing, segmentation, feature analysis, classification as well as integration with manufacturing process. The design and optimization of the above systems, especially image acquisition setup is mainly driven by experiment. This requires deep know-how and well equipped laboratory, which does not guarantee the optimal development process and results. This paper proposes novel usage of rendering, originating from 3D computer graphics, for machine vision prototyping and optimization. The invented technique and physically-based rendering aids selection or optimization of luminaires, tolerancing of mechanical construction and object handling, robustness predetermination or surface flaw simulation. The rendering setup utilizes mesh modeling, bump and normal mapping and light distribution sharpening with IES data files. The performed light simulation experiments for metal surfaces (face surface of bearing rollers) are validated.

  14. RenderMan design principles

    NASA Technical Reports Server (NTRS)

    Apodaca, Tony; Porter, Tom

    1989-01-01

    The two worlds of interactive graphics and realistic graphics have remained separate. Fast graphics hardware runs simple algorithms and generates simple looking images. Photorealistic image synthesis software runs slowly on large expensive computers. The time has come for these two branches of computer graphics to merge. The speed and expense of graphics hardware is no longer the barrier to the wide acceptance of photorealism. There is every reason to believe that high quality image synthesis will become a standard capability of every graphics machine, from superworkstation to personal computer. The significant barrier has been the lack of a common language, an agreed-upon set of terms and conditions, for 3-D modeling systems to talk to 3-D rendering systems for computing an accurate rendition of that scene. Pixar has introduced RenderMan to serve as that common language. RenderMan, specifically the extensibility it offers in shading calculations, is discussed.

  15. Fast data parallel polygon rendering

    SciTech Connect

    Ortega, F.A.; Hansen, C.D.

    1993-09-01

    This paper describes a parallel method for polygonal rendering on a massively parallel SIMD machine. This method, based on a simple shading model, is targeted for applications which require very fast polygon rendering for extremely large sets of polygons such as is found in many scientific visualization applications. The algorithms described in this paper are incorporated into a library of 3D graphics routines written for the Connection Machine. The routines are implemented on both the CM-200 and the CM-5. This library enables a scientists to display 3D shaded polygons directly from a parallel machine without the need to transmit huge amounts of data to a post-processing rendering system.

  16. Recording and rendering for art paintings based on multiband data

    NASA Astrophysics Data System (ADS)

    Tominaga, Shoji; Tanaka, Norihiro; Matsumoto, Toshinori

    2001-12-01

    The present paper proposes a method for recoding and rendering of art paintings using only spectral reflectance data of the object surfaces. A multiband camera system with six spectral channels of fixed wavelength bands is used for spectral imaging. No range finder is used for measuring the surface shape. We show that it is possible to render realistic images of the object for different directions of illumination, without using the 3D shape data. First, a method for estimating spectral reflectance for body reflection component of a rough surface is described. Next a method is proposed for practical image rendering. The method is based on interpolation among the images reproduced in the known illumination directions. The color signal for an arbitrary illumination direction is estimated from the color signals observed for three illumination directions. As a result, the image of an art painting object illuminated from any direction is rendered using the reflectance data obtained for three illumination directions. We present algorithms for estimating surface-spectral reflectances of an object and rendering the image for any lighting conditions. An experiment using an oil painting is executed for demonstrating the feasability of the proposed method.

  17. Progress in characterizing the multidimensional color quality properties of white LED light sources

    NASA Astrophysics Data System (ADS)

    Teunissen, Kees; Hoelen, Christoph

    2016-03-01

    With the introduction of solid state light sources, the variety in emission spectra is almost unlimited. However, the set of standardized parameters to characterize a white LED light source, such as correlated color temperature (CCT) and CIE general color rendering index (Ra), is known to be limited and insufficient for describing perceived differences between light sources. Several characterization methods have been proposed over the past decades, but their contribution to perceived color quality has not always been validated. To gain more insight in the relevant characteristics of the emission spectra for specific applications, we have conducted a perception experiment to rate the attractiveness of three sets of objects, including fresh food, packaging materials and skin tones. The objects were illuminated with seven different combinations of Red, Green, Blue, Amber and White LEDs, all with the same CCT and illumination level, but with differences in Ra and color saturation. The results show that, in general, object attractiveness does not correlate well with Ra, but shows a positive correlation with saturation increase for two out of three applications. There is no clear relation between saturation and skin tone attractiveness, partly due to differences in preference between males and females. A relative gamut area index (Ga) represents the average change in saturation and a complementary color vector graphic shows the direction and magnitude of chromatic differences for the eight CIE-1974 test-color samples. Together with the CIE general color rendering index (Ra) they provide useful information for designing and optimizing application specific emission spectra.

  18. Volume rendering for neurosurgical planning

    NASA Astrophysics Data System (ADS)

    Noordmans, Herke J.; Rutten, G. J. M.; Willems, Peter W. A.; van Veelen, C. W. M.; van Rijen, P. C.; Viergever, Max A.

    2001-01-01

    A volume rendering library is presented to interactively analyze volume data from modalities like CT, MR, PET, SPECT< and fMRI for the planning of nuerosurgical procedures. Current applications are logging of Penfield procedures, fMRI visualization, blood vessel visualization and interactive localization of EEG electrodes implanted in the subdural space of a patient with epilepsy.

  19. Text Rendering: Beginning Literary Response.

    ERIC Educational Resources Information Center

    Robertson, Sandra L.

    1990-01-01

    Argues that "text rendering"--responding to oral readings by saying back remembered words or phrases--forces students to prolong their initial responses to texts and opens initial response to the influence of other readers. Argues that silence following oral readings allows words to sink into students' minds, creating individual images and…

  20. Color M-mode Doppler flow propagation velocity is a preload insensitive index of left ventricular relaxation: animal and human validation

    NASA Technical Reports Server (NTRS)

    Garcia, M. J.; Smedira, N. G.; Greenberg, N. L.; Main, M.; Firstenberg, M. S.; Odabashian, J.; Thomas, J. D.

    2000-01-01

    OBJECTIVES: To determine the effect of preload in color M-mode Doppler flow propagation velocity (v(p)). BACKGROUND: The interpretation of Doppler filling patterns is limited by confounding effects of left ventricular (LV) relaxation and preload. Color M-mode v(p) has been proposed as a new index of LV relaxation. METHODS: We studied four dogs before and during inferior caval (IVC) occlusion at five different inotropic stages and 14 patients before and during partial cardiopulmonary bypass. Left ventricular (LV) end-diastolic volumes (LV-EDV), the time constant of isovolumic relaxation (tau), left atrial (LA) pre-A and LV end-diastolic pressures (LV-EDP) were measured. Peak velocity during early filling (E) and v(p) were extracted by digital analysis of color M-mode Doppler images. RESULTS: In both animals and humans, LV-EDV and LV-EDP decreased significantly from baseline to IVC occlusion (both p < 0.001). Peak early filling (E) velocity decreased in animals from 56 +/- 21 to 42 +/- 17 cm/s (p < 0.001) without change in v(p) (from 35 +/- 15 to 35 +/- 16, p = 0.99). Results were similar in humans (from 69 +/- 15 to 53 +/- 22 cm/s, p < 0.001, and 37 +/- 12 to 34 +/- 16, p = 0.30). In both species, there was a strong correlation between LV relaxation (tau) and v(p) (r = 0.78, p < 0.001, r = 0.86, p < 0.001). CONCLUSIONS: Our results indicate that color M-mode Doppler v(p) is not affected by preload alterations and confirms that LV relaxation is its main physiologic determinant in both animals during varying lusitropic conditions and in humans with heart disease.

  1. Sketchy Rendering for Information Visualization.

    PubMed

    Wood, J; Isenberg, P; Isenberg, T; Dykes, J; Boukhelifa, N; Slingsby, A

    2012-12-01

    We present and evaluate a framework for constructing sketchy style information visualizations that mimic data graphics drawn by hand. We provide an alternative renderer for the Processing graphics environment that redefines core drawing primitives including line, polygon and ellipse rendering. These primitives allow higher-level graphical features such as bar charts, line charts, treemaps and node-link diagrams to be drawn in a sketchy style with a specified degree of sketchiness. The framework is designed to be easily integrated into existing visualization implementations with minimal programming modification or design effort. We show examples of use for statistical graphics, conveying spatial imprecision and for enhancing aesthetic and narrative qualities of visualization. We evaluate user perception of sketchiness of areal features through a series of stimulus-response tests in order to assess users' ability to place sketchiness on a ratio scale, and to estimate area. Results suggest relative area judgment is compromised by sketchy rendering and that its influence is dependent on the shape being rendered. They show that degree of sketchiness may be judged on an ordinal scale but that its judgement varies strongly between individuals. We evaluate higher-level impacts of sketchiness through user testing of scenarios that encourage user engagement with data visualization and willingness to critique visualization design. Results suggest that where a visualization is clearly sketchy, engagement may be increased and that attitudes to participating in visualization annotation are more positive. The results of our work have implications for effective information visualization design that go beyond the traditional role of sketching as a tool for prototyping or its use for an indication of general uncertainty.

  2. Relationship between photochemical efficiency of photosystem II and the photochemical reflectance index of mango tree: merging data from different illuminations, seasons and leaf colors.

    PubMed

    Weng, Jen-Hsien; Jhaung, Lee-Hau; Lin, Rong-Jhih; Chen, Hong-Yi

    2010-04-01

    In order to elucidate the effects of chlorophyll concentration and seasonal temperature on the relationship between photosystem II (PSII) efficiency and the photochemical reflectance index (PRI) of leaves under different light intensity, mango (Mangifera indica), a low-temperature-sensitive species, was used for the study. From early winter to summer, we selected several days to measure chlorophyll fluorescence and leaf spectral reflectance of mango leaves with dark green to yellow green colors, under natural sunlight from predawn to sunset and under six levels (0, 200, 400, 800, 1200 and 2000 mumol m(-2) s(-1)) of artificial illumination. When leaves were exposed to light, both PRI and PSII efficiency decreased with the increase in illumination, yet the PSII efficiency-PRI relationship varied with temperature and leaf color. Both predawn PRI and the X-intercept of the PSII efficiency-PRI regression equations were higher in dark green leaves and on the day with higher minimum air temperature, and lower on opposite conditions. These were due to the influence of chlorophyll on the reflection of wavebands for detecting PRI, and leaves retained a higher degree of epoxidation state of xanthophyll cycle pigments in cold predawn. Therefore, when data obtained at different seasons and with different leaf colors were pooled for analysis, PRI was not closely related to PSII efficiency. Yet, either in the darkness of predawn or under a given level of illumination, PSII efficiency always showed a significant positive correlation with PRI, with data from different leaf colors and seasons merged for statistics analysis. Because both the intercept and slope of the PSII efficiency-PRI equation showed a negative regression with photosynthetic photon flux (PPF), an empirical regression model, i.e., PSII efficiency = c + d . PPF + e . (PPF)(2) + f . PRI + g . PPF . PRI, could be fitted for multiple regression analysis. Based on the close correlation between the estimated and measured

  3. Atmospheric correction of ocean color imagery: use of the junge power-law aerosol size distribution with variable refractive index to handle aerosol absorption.

    PubMed

    Chomko, R M; Gordon, H R

    1998-08-20

    When strongly absorbing aerosols are present in the atmosphere, the usual two-step procedure of processing ocean color data-(1) atmospheric correction to provide the water-leaving reflectance (rho(w)), followed by (2) relating rho(w) to the water constituents-fails and simultaneous estimation of the ocean and aerosol optical properties is necessary. We explore the efficacy of using a simple model of the aerosol-a Junge power-law size distribution consisting of homogeneous spheres with arbitrary refractive index-in a nonlinear optimization procedure for estimating the relevant oceanic and atmospheric parameters for case 1 waters. Using simulated test data generated from more realistic aerosol size distributions (sums of log-normally distributed components with different compositions), we show that the ocean's pigment concentration (C) can be retrieved with good accuracy in the presence of weakly or strongly absorbing aerosols. However, because of significant differences in the scattering phase functions for the test and power-law distributions, large error is possible in the estimate of the aerosol optical thickness. The positive result for C suggests that the detailed shape of the aerosol-scattering phase function is not relevant to the atmospheric correction of ocean color sensors. The relevant parameters are the aerosol single-scattering albedo and the spectral variation of the aerosol optical depth. We argue that the assumption of aerosol sphericity should not restrict the validity of the algorithm and suggest an avenue for including colored aerosols, e.g., wind-blown dust, in the procedure. A significant advantage of the new approach is that realistic multicomponent aerosol models are not required for the retrieval of C.

  4. Study of Perovskite QD Down-Converted LEDs and Six-Color White LEDs for Future Displays with Excellent Color Performance.

    PubMed

    Yoon, Hee Chang; Kang, Heejoon; Lee, Soyoung; Oh, Ji Hye; Yang, Heesun; Do, Young Rag

    2016-07-20

    A narrow-emitting red, green, and blue (RGB) perovskite quantum dot (PeQD)-based tricolored display system can widen the color gamut over the National Television System Committee (NTSC) to 120%, but this value is misleading with regard to the color perception of cyan and yellow reproduced in the narrow RGB spectra. We propose that a PeQD-based six-color display system can reproduce true-to-life spectral distributions with high fidelity, widen the color gamut, and close the cyan and yellow gap in the RGB tricolored display by adding cyan (Cy), yellowish green (Yg), and orange colors (Or). In this study, we demonstrated pure-colored CsPbX3 (X = Cl, Br, I, or their halide mixtures; Cl/Br and Br/I) PeQD-based monochromatic down-converted light-emitting diodes (DC-LED) for the first time, and we incorporated PeQDs with UV-curable binders and long-wavelength-pass-dichroic filters (LPDFs). CsPbX3 PeQD-based pure Cy-, G-, Yg-, Or-, R-emitting monochromatic DC-LED provide luminous efficacy (LE) values of 81, 184, 79, 80, and 35 lm/W, respectively, at 20 mA. We also confirmed the suitability and the possibility of access to future color-by-blue backlights for field-sequential-color liquid crystal displays, using six-color multipackage white LEDs, as well as future six-colored light-emitting devices with high vision and color performance. The fabricated six-color multipackage white LEDs exhibited an appropriate LE (62 lm/W at total 120 mA), excellent color qualities (color rendering index (CRI) = 96, special CRI for red (R9) = 97) at a correlated color temperature (CCT) of 6500 K, and a wide color gamut covering the NTSC up to 145% in the 1931 Commission International de l'Eclairage (CIE) color coordinates space. PMID:27349270

  5. Study of Perovskite QD Down-Converted LEDs and Six-Color White LEDs for Future Displays with Excellent Color Performance.

    PubMed

    Yoon, Hee Chang; Kang, Heejoon; Lee, Soyoung; Oh, Ji Hye; Yang, Heesun; Do, Young Rag

    2016-07-20

    A narrow-emitting red, green, and blue (RGB) perovskite quantum dot (PeQD)-based tricolored display system can widen the color gamut over the National Television System Committee (NTSC) to 120%, but this value is misleading with regard to the color perception of cyan and yellow reproduced in the narrow RGB spectra. We propose that a PeQD-based six-color display system can reproduce true-to-life spectral distributions with high fidelity, widen the color gamut, and close the cyan and yellow gap in the RGB tricolored display by adding cyan (Cy), yellowish green (Yg), and orange colors (Or). In this study, we demonstrated pure-colored CsPbX3 (X = Cl, Br, I, or their halide mixtures; Cl/Br and Br/I) PeQD-based monochromatic down-converted light-emitting diodes (DC-LED) for the first time, and we incorporated PeQDs with UV-curable binders and long-wavelength-pass-dichroic filters (LPDFs). CsPbX3 PeQD-based pure Cy-, G-, Yg-, Or-, R-emitting monochromatic DC-LED provide luminous efficacy (LE) values of 81, 184, 79, 80, and 35 lm/W, respectively, at 20 mA. We also confirmed the suitability and the possibility of access to future color-by-blue backlights for field-sequential-color liquid crystal displays, using six-color multipackage white LEDs, as well as future six-colored light-emitting devices with high vision and color performance. The fabricated six-color multipackage white LEDs exhibited an appropriate LE (62 lm/W at total 120 mA), excellent color qualities (color rendering index (CRI) = 96, special CRI for red (R9) = 97) at a correlated color temperature (CCT) of 6500 K, and a wide color gamut covering the NTSC up to 145% in the 1931 Commission International de l'Eclairage (CIE) color coordinates space.

  6. Development of the IES method for evaluating the color rendition of light sources

    DOE PAGESBeta

    David, Aurelien; Fini, Paul T.; Houser, Kevin W.; Ohno, Yoshi; Royer, Michael P.; USA, Richland Washington; Smet, Kevin A. G.; Wei, Minchen; Whitehead, Lorne

    2015-06-08

    We have developed a two-measure system for evaluating light sources’ color rendition that builds upon conceptual progress of numerous researchers over the last two decades. The system quantifies the color fidelity and color gamut (change in object chroma) of a light source in comparison to a reference illuminant. The calculations are based on a newly developed set of reflectance data from real samples uniformly distributed in color space (thereby fairly representing all colors) and in wavelength space (thereby precluding artificial optimization of the color rendition scores by spectral engineering). The color fidelity score Rf is an improved version of themore » CIE color rendering index. The color gamut score Rg is an improved version of the Gamut Area Index. In combination, they provide two complementary assessments to guide the optimization of future light sources. This method summarizes the findings of the Color Metric Task Group of the Illuminating Engineering Society of North America (IES). It is adopted in the upcoming IES TM-30-2015, and is proposed for consideration with the International Commission on Illumination (CIE).« less

  7. Development of the IES method for evaluating the color rendition of light sources.

    PubMed

    David, Aurelien; Fini, Paul T; Houser, Kevin W; Ohno, Yoshi; Royer, Michael P; Smet, Kevin A G; Wei, Minchen; Whitehead, Lorne

    2015-06-15

    We have developed a two-measure system for evaluating light sources' color rendition that builds upon conceptual progress of numerous researchers over the last two decades. The system quantifies the color fidelity and color gamut (change in object chroma) of a light source in comparison to a reference illuminant. The calculations are based on a newly developed set of reflectance data from real samples uniformly distributed in color space (thereby fairly representing all colors) and in wavelength space (thereby precluding artificial optimization of the color rendition scores by spectral engineering). The color fidelity score R(f) is an improved version of the CIE color rendering index. The color gamut score R(g) is an improved version of the Gamut Area Index. In combination, they provide two complementary assessments to guide the optimization of future light sources. This method summarizes the findings of the Color Metric Task Group of the Illuminating Engineering Society of North America (IES). It is adopted in the upcoming IES TM-30-2015, and is proposed for consideration with the International Commission on Illumination (CIE).

  8. Development of the IES method for evaluating the color rendition of light sources

    SciTech Connect

    David, Aurelien; Fini, Paul T.; Houser, Kevin W.; Ohno, Yoshi; Royer, Michael P.; USA, Richland Washington; Smet, Kevin A. G.; Whitehead, Lorne

    2015-06-08

    We have developed a two-measure system for evaluating light sources’ color rendition that builds upon conceptual progress of numerous researchers over the last two decades. The system quantifies the color fidelity and color gamut (change in object chroma) of a light source in comparison to a reference illuminant. The calculations are based on a newly developed set of reflectance data from real samples uniformly distributed in color space (thereby fairly representing all colors) and in wavelength space (thereby precluding artificial optimization of the color rendition scores by spectral engineering). The color fidelity score Rf is an improved version of the CIE color rendering index. The color gamut score Rg is an improved version of the Gamut Area Index. In combination, they provide two complementary assessments to guide the optimization of future light sources. This method summarizes the findings of the Color Metric Task Group of the Illuminating Engineering Society of North America (IES). It is adopted in the upcoming IES TM-30-2015, and is proposed for consideration with the International Commission on Illumination (CIE).

  9. Linked-View Parallel Coordinate Plot Renderer

    2011-06-28

    This software allows multiple linked views for interactive querying via map-based data selection, bar chart analytic overlays, and high dynamic range (HDR) line renderings. The major component of the visualization package is a parallel coordinate renderer with binning, curved layouts, shader-based rendering, and other techniques to allow interactive visualization of multidimensional data.

  10. Volume Rendering of AMR Simulations

    NASA Astrophysics Data System (ADS)

    Labadens, M.; Pomarède, D.; Chapon, D.; Teyssier, R.; Bournaud, F.; Renaud, F.; Grandjouan, N.

    2013-04-01

    High-resolution simulations often rely on the Adaptive Mesh Resolution (AMR) technique to optimize memory consumption versus attainable precision. While this technique allows for dramatic improvements in terms of computing performance, the analysis and visualization of its data outputs remain challenging. The lack of effective volume renderers for the octree-based AMR used by the RAMSES simulation program has led to the development of the solutions presented in this paper. Two custom algorithms are discussed, based on the splatting and the ray-casting techniques. Their usage is illustrated in the context of the visualization of a high-resolution, 6000-processor simulation of a Milky Way-like galaxy. Performance obtained in terms of memory management and parallelism speedup are presented.

  11. Equivalent Colorings with "Maple"

    ERIC Educational Resources Information Center

    Cecil, David R.; Wang, Rongdong

    2005-01-01

    Many counting problems can be modeled as "colorings" and solved by considering symmetries and Polya's cycle index polynomial. This paper presents a "Maple 7" program link http://users.tamuk.edu/kfdrc00/ that, given Polya's cycle index polynomial, determines all possible associated colorings and their partitioning into equivalence classes. These…

  12. Matching rendered and real world images by digital image processing

    NASA Astrophysics Data System (ADS)

    Mitjà, Carles; Bover, Toni; Bigas, Miquel; Escofet, Jaume

    2010-05-01

    Recent advances in computer-generated images (CGI) have been used in commercial and industrial photography providing a broad scope in product advertising. Mixing real world images with those rendered from virtual space software shows a more or less visible mismatching between corresponding image quality performance. Rendered images are produced by software which quality performance is only limited by the resolution output. Real world images are taken with cameras with some amount of image degradation factors as lens residual aberrations, diffraction, sensor low pass anti aliasing filters, color pattern demosaicing, etc. The effect of all those image quality degradation factors can be characterized by the system Point Spread Function (PSF). Because the image is the convolution of the object by the system PSF, its characterization shows the amount of image degradation added to any taken picture. This work explores the use of image processing to degrade the rendered images following the parameters indicated by the real system PSF, attempting to match both virtual and real world image qualities. The system MTF is determined by the slanted edge method both in laboratory conditions and in the real picture environment in order to compare the influence of the working conditions on the device performance; an approximation to the system PSF is derived from the two measurements. The rendered images are filtered through a Gaussian filter obtained from the taking system PSF. Results with and without filtering are shown and compared measuring the contrast achieved in different final image regions.

  13. Binaural Rendering in MPEG Surround

    NASA Astrophysics Data System (ADS)

    Breebaart, Jeroen; Villemoes, Lars; Kjörling, Kristofer

    2008-12-01

    This paper describes novel methods for evoking a multichannel audio experience over stereo headphones. In contrast to the conventional convolution-based approach where, for example, five input channels are filtered using ten head-related transfer functions, the current approach is based on a parametric representation of the multichannel signal, along with either a parametric representation of the head-related transfer functions or a reduced set of head-related transfer functions. An audio scene with multiple virtual sound sources is represented by a mono or a stereo downmix signal of all sound source signals, accompanied by certain statistical (spatial) properties. These statistical properties of the sound sources are either combined with statistical properties of head-related transfer functions to estimate "binaural parameters" that represent the perceptually relevant aspects of the auditory scene or used to create a limited set of combined head-related transfer functions that can be applied directly on the downmix signal. Subsequently, a binaural rendering stage reinstates the statistical properties of the sound sources by applying the estimated binaural parameters or the reduced set of combined head-related transfer functions directly on the downmix. If combined with parametric multichannel audio coders such as MPEG Surround, the proposed methods are advantageous over conventional methods in terms of perceived quality and computational complexity.

  14. Interactive rendering of dynamic geometry.

    PubMed

    Ponchio, Federico; Hormann, Kai

    2008-01-01

    Fluid simulations typically produce complex three-dimensional (3D) isosurfaces whose geometry and topology change over time. The standard way of representing such "dynamic geometry" is by a set of isosurfaces that are extracted individually at certain time steps. An alternative strategy is to represent the whole sequence as a four-dimensional (4D) tetrahedral mesh. The iso-surface at a specific time step can then be computed by intersecting the tetrahedral mesh with a 3D hyperplane. This not only allows the animation of the surface continuously over time without having to worry about the topological changes, but also enables simplification algorithms to exploit temporal coherence. We show how to interactively render such 4D tetrahedral meshes by improving previous GPU-accelerated techniques and building an out-of-core multi-resolution structure based on quadric error simplification. As a second application, we apply our framework to time-varying surfaces that result from morphing one triangle mesh into another. PMID:18467764

  15. RenderToolbox3: MATLAB tools that facilitate physically based stimulus rendering for vision research.

    PubMed

    Heasly, Benjamin S; Cottaris, Nicolas P; Lichtman, Daniel P; Xiao, Bei; Brainard, David H

    2014-02-07

    RenderToolbox3 provides MATLAB utilities and prescribes a workflow that should be useful to researchers who want to employ graphics in the study of vision and perhaps in other endeavors as well. In particular, RenderToolbox3 facilitates rendering scene families in which various scene attributes and renderer behaviors are manipulated parametrically, enables spectral specification of object reflectance and illuminant spectra, enables the use of physically based material specifications, helps validate renderer output, and converts renderer output to physical units of radiance. This paper describes the design and functionality of the toolbox and discusses several examples that demonstrate its use. We have designed RenderToolbox3 to be portable across computer hardware and operating systems and to be free and open source (except for MATLAB itself). RenderToolbox3 is available at https://github.com/DavidBrainard/RenderToolbox3.

  16. RenderToolbox3: MATLAB tools that facilitate physically based stimulus rendering for vision research

    PubMed Central

    Heasly, Benjamin S.; Cottaris, Nicolas P.; Lichtman, Daniel P.; Xiao, Bei; Brainard, David H.

    2014-01-01

    RenderToolbox3 provides MATLAB utilities and prescribes a workflow that should be useful to researchers who want to employ graphics in the study of vision and perhaps in other endeavors as well. In particular, RenderToolbox3 facilitates rendering scene families in which various scene attributes and renderer behaviors are manipulated parametrically, enables spectral specification of object reflectance and illuminant spectra, enables the use of physically based material specifications, helps validate renderer output, and converts renderer output to physical units of radiance. This paper describes the design and functionality of the toolbox and discusses several examples that demonstrate its use. We have designed RenderToolbox3 to be portable across computer hardware and operating systems and to be free and open source (except for MATLAB itself). RenderToolbox3 is available at https://github.com/DavidBrainard/RenderToolbox3. PMID:24511145

  17. Hierarchical image-based rendering using texture mapping hardware

    SciTech Connect

    Max, N

    1999-01-15

    Multi-layered depth images containing color and normal information for subobjects in a hierarchical scene model are precomputed with standard z-buffer hardware for six orthogonal views. These are adaptively selected according to the proximity of the viewpoint, and combined using hardware texture mapping to create ''reprojected'' output images for new viewpoints. (If a subobject is too close to the viewpoint, the polygons in the original model are rendered.) Specific z-ranges are selected from the textures with the hardware alpha test to give accurate 3D reprojection. The OpenGL color matrix is used to transform the precomputed normals into their orientations in the final view, for hardware shading.

  18. Parallel rendering techniques for massively parallel visualization

    SciTech Connect

    Hansen, C.; Krogh, M.; Painter, J.

    1995-07-01

    As the resolution of simulation models increases, scientific visualization algorithms which take advantage of the large memory. and parallelism of Massively Parallel Processors (MPPs) are becoming increasingly important. For large applications rendering on the MPP tends to be preferable to rendering on a graphics workstation due to the MPP`s abundant resources: memory, disk, and numerous processors. The challenge becomes developing algorithms that can exploit these resources while minimizing overhead, typically communication costs. This paper will describe recent efforts in parallel rendering for polygonal primitives as well as parallel volumetric techniques. This paper presents rendering algorithms, developed for massively parallel processors (MPPs), for polygonal, spheres, and volumetric data. The polygon algorithm uses a data parallel approach whereas the sphere and volume render use a MIMD approach. Implementations for these algorithms are presented for the Thinking Ma.chines Corporation CM-5 MPP.

  19. Capturing, processing, and rendering real-world scenes

    NASA Astrophysics Data System (ADS)

    Nyland, Lars S.; Lastra, Anselmo A.; McAllister, David K.; Popescu, Voicu; McCue, Chris; Fuchs, Henry

    2000-12-01

    While photographs vividly capture a scene from a single viewpoint, it is our goal to capture a scene in such a way that a viewer can freely move to any viewpoint, just as he or she would in an actual scene. We have built a prototype system to quickly digitize a scene using a laser rangefinder and a high-resolution digital camera that accurately captures a panorama of high-resolution range and color information. With real-world scenes, we have provided data to fuel research in many area, including representation, registration, data fusion, polygonization, rendering, simplification, and reillumination. The real-world scene data can be used for many purposes, including immersive environments, immersive training, re-engineering and engineering verification, renovation, crime-scene and accident capture and reconstruction, archaeology and historic preservation, sports and entertainment, surveillance, remote tourism and remote sales. We will describe our acquisition system, the necessary processing to merge data from the multiple input devices and positions. We will also describe high quality rendering using the data we have collected. Issues about specific rendering accelerators and algorithms will also be presented. We will conclude by describing future uses and methods of collection for real- world scene data.

  20. Object-oriented parallel polygon rendering

    SciTech Connect

    Heiland, R.W.

    1994-09-01

    Since many scientific datasets can be visualized using some polygonal representation, a polygon renderer has broad use for scientific visualization. With today`s high performance computing applications producing very large datasets, a parallel polygon renderer is a necessary tool for keeping the compute-visualize cycle at a minimum. This paper presents a DOIV on renderer that combines the shared-memory and message-passing models of parallel programming. It uses the Global Arrays library, a shared-memory programming toolkit for distributed memory machines. The experience of using an object oriented approach for software design and development is also discussed.

  1. Fast volume rendering for medical image.

    PubMed

    Ying, Hu; Xin-He, Xu

    2005-01-01

    In orders to improve the rendering speed of ray casting and make this technique a practical routine in medical applications, two new and improved techniques are described in this paper. First, an integrated method using "proximity clouds" technique is applied to speed up ray casting. The second technique for speeding up the 3D rendering is done through a parallel implementation based on "single computer multi CPU" model Four groups of CT data sets have been used to validate the improvement of the rendering speed. The result shown that the interactive rendering speed is up to 6-10 fps, which is almost real-time making our algorithm practical in medical visualization routine.

  2. Foundations for Measuring Volume Rendering Quality

    NASA Technical Reports Server (NTRS)

    Williams, Peter L.; Uselton, Samuel P.; Chancellor, Marisa K. (Technical Monitor)

    1997-01-01

    The goal of this paper is to provide a foundation for objectively comparing volume rendered images. The key elements of the foundation are: (1) a rigorous specification of all the parameters that need to be specified to define the conditions under which a volume rendered image is generated; (2) a methodology for difference classification, including a suite of functions or metrics to quantify and classify the difference between two volume rendered images that will support an analysis of the relative importance of particular differences. The results of this method can be used to study the changes caused by modifying particular parameter values, to compare and quantify changes between images of similar data sets rendered in the same way, and even to detect errors in the design, implementation or modification of a volume rendering system. If one has a benchmark image, for example one created by a high accuracy volume rendering system, the method can be used to evaluate the accuracy of a given image.

  3. Color Blindness

    MedlinePlus

    ... three color cone cells to determine our color perception. Color blindness can occur when one or more ... Anyone who experiences a significant change in color perception should see an ophthalmologist (Eye M.D.). Next ...

  4. Color blindness

    MedlinePlus

    Color deficiency; Blindness - color ... Color blindness occurs when there is a problem with the pigments in certain nerve cells of the eye that sense color. These cells are called cones. They are found ...

  5. Color Blindness

    MedlinePlus

    ... rose in full bloom. If you have a color vision defect, you may see these colors differently than most people. There are three main kinds of color vision defects. Red-green color vision defects are the ...

  6. OLED-based physiologically-friendly very low-color temperature illumination for night

    NASA Astrophysics Data System (ADS)

    Jou, Jwo-Huei; Shen, Shih-Ming; Tang, Ming-Chun; Chen, Pin-Chu; Chen, Szu-Hao; Wang, Yi-Shan; Chen, Chien-Chih; Wang, Ching-Chun; Hsieh, Chun-Yu; Lin, Chin-Chiao; Chen, Chien-Tien

    2012-09-01

    Numerous medical research studies reveal intense white or blue light to drastically suppress at night the secretion of melatonin (MLT), a protective oncostatic hormone. Lighting devices with lower color-temperature (CT) possess lesser MLT suppression effect based on the same luminance, explaining why physicians have long been calling for the development of lighting sources with low CT or free from blue emission for use at night to safeguard human health. We will demonstrate in the presentation the fabrication of OLED devices with very-low CT, especially those with CT much lower than that of incandescent bulbs (2500K) or even candles (2000K). Without any light extraction method, OLEDs with an around 1800K CT are easily obtainable with an efficacy of 30 lm/W at 1,000 nits. To also ensure high color-rendering to provide visual comfort, low CT OLEDs composing long wavelength dominant 5-spectrum emission have been fabricated. While keeping the color-rendering index as high as 85 and CT as low as 2100K, the resulting efficacy can also be much greater than that of incandescent bulbs (15 lm/W), proving these low CT OLED devices to be also capable of being energy-saving and high quality. The color-temperature can be further decreased to 1700K or lower upon removing the undesired short wavelength emission but on the cost of losing some color rendering index. It is hoped that the devised energy-saving, high quality low CT OLED could properly echo the call for a physiologically-friendly illumination for night, and more attention could be drawn to the development of MLT suppression-less non-white light.

  7. Preferred color spaces for white balancing

    NASA Astrophysics Data System (ADS)

    Xiao, Feng; Farrell, Joyce E.; DiCarlo, Jeffrey M.; Wandell, Brian A.

    2003-05-01

    When rendering photographs, it is important to preserve the gray tones despite variations in the ambient illumination. When the illuminant is known, white balancing that preserves gray tones can be performed in many different color spaces; the choice of color space influences the renderings of other colors. In this behavioral study, we ask whether users have a preference for the color space where white balancing is performed. Subjects compared images using a white balancing transformation that preserved gray tones, but the transformation was applied in one of the four different color spaces: XYZ, Bradford, a camera sensor RGB and the sharpened RGB color space. We used six scenes types (four portraits, fruit, and toys) acquired under three calibrated illumination environments (fluorescent, tungsten, and flash). For all subjects, transformations applied in XYZ and sharpened RGB were preferred to those applied in Bradford and device color space.

  8. Color contrast enhancement for color night vision based on color mapping

    NASA Astrophysics Data System (ADS)

    Qian, Xiaoyan; Han, Lei; Wang, Yujin; Wang, Bangfeng

    2013-03-01

    The increasing availability and deployment of imaging sensors operating in multiple spectral bands has led to a large research effort in image fusion, bringing a lot of pixel-level color fusion algorithms. Color constancy and color contrast are two important topics for color image fusion. However, there is no work considering these two aspects in the meanwhile. The paper focuses on enhancing the color contrast between targets and their backgrounds and maintaining the color constancy. Firstly, a group of visible and infrared images are rendered with natural colors with color contrast enhancement algorithm. Then a color reference palette is derived from source images and their corresponding fused results. To enrich this palette, the nearest Euclidean distance determines the absent colors. The complete palette can be deployed in real-time to different multi-band image sequences of similar scenes. Experimental results based on different data sets show that the targets are popped out with intense colors while backgrounds present natural color appearance. Some objective analysis also shows that the presented method not only inherits more detail information from source images but also brings bigger color distance when comparing with the existing algorithms.

  9. Standardized rendering from IR surveillance motion imagery

    NASA Astrophysics Data System (ADS)

    Prokoski, F. J.

    2014-06-01

    Government agencies, including defense and law enforcement, increasingly make use of video from surveillance systems and camera phones owned by non-government entities.Making advanced and standardized motion imaging technology available to private and commercial users at cost-effective prices would benefit all parties. In particular, incorporating thermal infrared into commercial surveillance systems offers substantial benefits beyond night vision capability. Face rendering is a process to facilitate exploitation of thermal infrared surveillance imagery from the general area of a crime scene, to assist investigations with and without cooperating eyewitnesses. Face rendering automatically generates greyscale representations similar to police artist sketches for faces in surveillance imagery collected from proximate locations and times to a crime under investigation. Near-realtime generation of face renderings can provide law enforcement with an investigation tool to assess witness memory and credibility, and integrate reports from multiple eyewitnesses, Renderings can be quickly disseminated through social media to warn of a person who may pose an immediate threat, and to solicit the public's help in identifying possible suspects and witnesses. Renderings are pose-standardized so as to not divulge the presence and location of eyewitnesses and surveillance cameras. Incorporation of thermal infrared imaging into commercial surveillance systems will significantly improve system performance, and reduce manual review times, at an incremental cost that will continue to decrease. Benefits to criminal justice would include improved reliability of eyewitness testimony and improved accuracy of distinguishing among minority groups in eyewitness and surveillance identifications.

  10. Volume Rendering for Curvilinear and Unstructured Grids

    SciTech Connect

    Max, N; Williams, P; Silva, C; Cook, R

    2003-03-05

    We discuss two volume rendering methods developed at Lawrence Livermore National Laboratory. The first, cell projection, renders the polygons in the projection of each cell. It requires a global visibility sort in order to composite the cells in back to front order, and we discuss several different algorithms for this sort. The second method uses regularly spaced slice planes perpendicular to the X, Y, or Z axes, which slice the cells into polygons. Both methods are supplemented with anti-aliasing techniques to deal with small cells that might fall between pixel samples or slice planes, and both have been parallelized.

  11. Feature-driven data exploration for volumetric rendering.

    PubMed

    Woo, Insoo; Maciejewski, Ross; Gaither, Kelly P; Ebert, David S

    2012-10-01

    We have developed an intuitive method to semiautomatically explore volumetric data in a focus-region-guided or value-driven way using a user-defined ray through the 3D volume and contour lines in the region of interest. After selecting a point of interest from a 2D perspective, which defines a ray through the 3D volume, our method provides analytical tools to assist in narrowing the region of interest to a desired set of features. Feature layers are identified in a 1D scalar value profile with the ray and are used to define default rendering parameters, such as color and opacity mappings, and locate the center of the region of interest. Contour lines are generated based on the feature layer level sets within interactively selected slices of the focus region. Finally, we utilize feature-preserving filters and demonstrate the applicability of our scheme to noisy data. PMID:22291153

  12. Feature-driven data exploration for volumetric rendering.

    PubMed

    Woo, Insoo; Maciejewski, Ross; Gaither, Kelly P; Ebert, David S

    2012-10-01

    We have developed an intuitive method to semiautomatically explore volumetric data in a focus-region-guided or value-driven way using a user-defined ray through the 3D volume and contour lines in the region of interest. After selecting a point of interest from a 2D perspective, which defines a ray through the 3D volume, our method provides analytical tools to assist in narrowing the region of interest to a desired set of features. Feature layers are identified in a 1D scalar value profile with the ray and are used to define default rendering parameters, such as color and opacity mappings, and locate the center of the region of interest. Contour lines are generated based on the feature layer level sets within interactively selected slices of the focus region. Finally, we utilize feature-preserving filters and demonstrate the applicability of our scheme to noisy data.

  13. Efficient hardware accelerated rendering of multiple volumes by data dependent local render functions

    NASA Astrophysics Data System (ADS)

    Lehmann, Helko; Geller, Dieter; Weese, Jürgen; Kiefer, Gundolf

    2007-03-01

    The inspection of a patient's data for diagnostics, therapy planning or therapy guidance involves an increasing number of 3D data sets, e.g. acquired by different imaging modalities, with different scanner settings or at different times. To enable viewing of the data in one consistent anatomical context fused interactive renderings of multiple 3D data sets are desirable. However, interactive fused rendering of typical medical data sets using standard computing hardware remains a challenge. In this paper we present a method to render multiple 3D data sets. By introducing local rendering functions, i.e. functions that are adapted to the complexity of the visible data contained in the different regions of a scene, we can ensure that the overall performance for fused rendering of multiple data sets depends on the actual amount of visible data. This is in contrast to other approaches where the performance depends mainly on the number of rendered data sets. We integrate the method into a streaming rendering architecture with brick-based data representations of the volume data. This enables efficient handling of data sets that do not fit into the graphics board memory and a good utilization of the texture caches. Furthermore, transfer and rendering of volume data that does not contribute to the final image can be avoided. We illustrate the benefits of our method by experiments with clinical data.

  14. Fast polyhedral cell sorting for interactive rendering of unstructured grids

    SciTech Connect

    Combra, J; Klosowski, J T; Max, N; Silva, C T; Williams, P L

    1998-10-30

    Direct volume rendering based on projective methods works by projecting, in visibility order, the polyhedral cells of a mesh onto the image plane, and incrementally compositing the cell's color and opacity into the final image. Crucial to this method is the computation of a visibility ordering of the cells. If the mesh is ''well-behaved'' (acyclic and convex), then the MPVO method of Williams provides a very fast sorting algorithm; however, this method only computes an approximate ordering in general datasets, resulting in visual artifacts when rendered. A recent method of Silva et al. removed the assumption that the mesh is convex, by means of a sweep algorithm used in conjunction with the MPVO method; their algorithm is substantially faster than previous exact methods for general meshes. In this paper we propose a new technique, which we call BSP-XMPVO, which is based on a fast and simple way of using binary space partitions on the boundary elements of the mesh to augment the ordering produced by MPVO. Our results are shown to be orders of magnitude better than previous exact methods of sorting cells.

  15. Direct Volume Rendering with Shading via Three-Dimensional Textures

    NASA Technical Reports Server (NTRS)

    Van Gelder, Allen; Kim, Kwansik

    1996-01-01

    A new and easy-to-implement method for direct volume rendering that uses 3D texture maps for acceleration, and incorporates directional lighting, is described. The implementation, called Voltx, produces high-quality images at nearly interactive speeds on workstations with hardware support for three-dimensional texture maps. Previously reported methods did not incorporate a light model, and did not address issues of multiple texture maps for large volumes. Our research shows that these extensions impact performance by about a factor of ten. Voltx supports orthographic, perspective, and stereo views. This paper describes the theory and implementation of this technique, and compares it to the shear-warp factorization approach. A rectilinear data set is converted into a three-dimensional texture map containing color and opacity information. Quantized normal vectors and a lookup table provide efficiency. A new tesselation of the sphere is described, which serves as the basis for normal-vector quantization. A new gradient-based shading criterion is described, in which the gradient magnitude is interpreted in the context of the field-data value and the material classification parameters, and not in isolation. In the rendering phase, the texture map is applied to a stack of parallel planes, which effectively cut the texture into many slabs. The slabs are composited to form an image.

  16. ProteinShader: illustrative rendering of macromolecules

    PubMed Central

    Weber, Joseph R

    2009-01-01

    Background Cartoon-style illustrative renderings of proteins can help clarify structural features that are obscured by space filling or balls and sticks style models, and recent advances in programmable graphics cards offer many new opportunities for improving illustrative renderings. Results The ProteinShader program, a new tool for macromolecular visualization, uses information from Protein Data Bank files to produce illustrative renderings of proteins that approximate what an artist might create by hand using pen and ink. A combination of Hermite and spherical linear interpolation is used to draw smooth, gradually rotating three-dimensional tubes and ribbons with a repeating pattern of texture coordinates, which allows the application of texture mapping, real-time halftoning, and smooth edge lines. This free platform-independent open-source program is written primarily in Java, but also makes extensive use of the OpenGL Shading Language to modify the graphics pipeline. Conclusion By programming to the graphics processor unit, ProteinShader is able to produce high quality images and illustrative rendering effects in real-time. The main feature that distinguishes ProteinShader from other free molecular visualization tools is its use of texture mapping techniques that allow two-dimensional images to be mapped onto the curved three-dimensional surfaces of ribbons and tubes with minimum distortion of the images. PMID:19331660

  17. Cone Tracing for Furry Object Rendering.

    PubMed

    Qin, Hao; Chai, Menglei; Hou, Qiming; Ren, Zhong; Zhou, Kun

    2014-08-01

    We present a cone-based ray tracing algorithm for high-quality rendering of furry objects with reflection, refraction and defocus effects. By aggregating many sampling rays in a pixel as a single cone, we significantly reduce the high supersampling rate required by the thin geometry of fur fibers. To reduce the cost of intersecting fur fibers with cones, we construct a bounding volume hierarchy for the fiber geometry to find the fibers potentially intersecting with cones, and use a set of connected ribbons to approximate the projections of these fibers on the image plane. The computational cost of compositing and filtering transparent samples within each cone is effectively reduced by approximating away in-cone variations of shading, opacity and occlusion. The result is a highly efficient ray tracing algorithm for furry objects which is able to render images of quality comparable to those generated by alternative methods, while significantly reducing the rendering time. We demonstrate the rendering quality and performance of our algorithm using several examples and a user study. PMID:26357369

  18. Rendering Visible: Painting and Sexuate Subjectivity

    ERIC Educational Resources Information Center

    Daley, Linda

    2015-01-01

    In this essay, I examine Luce Irigaray's aesthetic of sexual difference, which she develops by extrapolating from Paul Klee's idea that the role of painting is to render the non-visible rather than represent the visible. This idea is the premise of her analyses of phenomenology and psychoanalysis and their respective contributions to understanding…

  19. Rapid Decimation for Direct Volume Rendering

    NASA Technical Reports Server (NTRS)

    Gibbs, Jonathan; VanGelder, Allen; Verma, Vivek; Wilhelms, Jane

    1997-01-01

    An approach for eliminating unnecessary portions of a volume when producing a direct volume rendering is described. This reduction in volume size sacrifices some image quality in the interest of rendering speed. Since volume visualization is often used as an exploratory visualization technique, it is important to reduce rendering times, so the user can effectively explore the volume. The methods presented can speed up rendering by factors of 2 to 3 with minor image degradation. A family of decimation algorithms to reduce the number of primitives in the volume without altering the volume's grid in any way is introduced. This allows the decimation to be computed rapidly, making it easier to change decimation levels on the fly. Further, because very little extra space is required, this method is suitable for the very large volumes that are becoming common. The method is also grid-independent, so it is suitable for multiple overlapping curvilinear and unstructured, as well as regular, grids. The decimation process can proceed automatically, or can be guided by the user so that important regions of the volume are decimated less than unimportant regions. A formal error measure is described based on a three-dimensional analog of the Radon transform. Decimation methods are evaluated based on this metric and on direct comparison with reference images.

  20. Shapes and textures for rendering coral

    SciTech Connect

    Max, N.L. ); Wyvill, G. )

    1990-10-18

    A growth algorithm has been developed to build coral shapes out of a tree of spheres. A volume density defined by the spheres is contoured to give a soft object.'' The resulting contour surfaces are rendered by ray tracing, using a generalized volume texture to produce shading and bump mapped'' normal perturbations. 16 refs., 8 figs.

  1. Comparison of volume-rendered and surface-rendered MR colonography.

    PubMed

    Heuschmid, Martin; Luz, Oliver; Schaefer, Juergen F; Stuecker, Dietmar; Vonthein, Reinhard; Luboldt, Wolfgang; Claussen, Claus D; Seemann, Marcus D

    2003-02-01

    In the United States and Europe, colorectal cancer is the second leading cause of cancer-related deaths. It is well known that colorectal carcinomas may originate from preexisting adenomas. For the visualization of colorectal cancer and other pathologic changes such as polyps, two 3D methods (volume-rendering (VR) and surface-rendering (SR)) in MR colonography were compared in our study. MR colonography was carried out in 17 patients on a 1.5 T MR scanner using a 10 mmolar gadolinium water solution enema. Coronal as well as rotated VR and SR views were compared in order to examine the technical quality (TQ) of the visualization model and grade of confidence (GC) in the pathological findings. Colonoscopic findings revealed 8 colorectal carcinoma, 10 patients with polyps, 4 diverticular disease, and 2 with redundant bowel loops. Based on a total of 248 colonic segments for both visualization methods, volume rendering were significantly superior to surface rendering for both, TQ (p<0.0001) and GC (p<0.0001). Volume rendering and surface rendering were not dependent on individual colon segments (p=0.13 for TQ and p=0.18 for GC) or on image rotation (p=0.06 for TQ and p=0.062 for GC). It is also independent of the type of pathology (p=0.31 for TQ and p=0.42 for GC) and the reviewers (p=0.62 for TQ and p=0.88 for GC). This indicates, that for the purpose of interpreting the technical quality and pathological findings, volume rendering is superior to surface rendering in MR colonography. Volume rendering could be used as an 3D visualization tool, enabling MR colonography examinations to be completed sooner in cases where colon distension is sufficient, and it would also provide an overview of potential mass lesions. PMID:12625749

  2. NASA 1981 photography index

    NASA Technical Reports Server (NTRS)

    1982-01-01

    An index of representative photographs is presented. Color transparencies and black and white glossies of major launches, Mariner spacecraft, Pioneer spacecraft, planets and other space phenomena, Skylab, space shuttle, Viking spacecraft, and Voyager spacecraft are included.

  3. Polymeric Inverse Glasses for Development of Noniridescent Structural Colors in Full Visible Range.

    PubMed

    Lee, Gun Ho; Sim, Jae Young; Kim, Shin-Hyun

    2016-05-18

    Amorphous colloidal array with short-range order displays noniridescent structural colors due to the isotropic nature of the colloidal arrangement. The low angle dependence renders the colloidal glasses, which is promising for various coloration applications. Nevertheless, the colloidal glasses are difficult to develop red structural color due to strong cavity-like resonance from individual particles in the blue region. To suppress the cavity mode and develop the colors in the full visible range, we prepare inverse glasses composed of amorphous array of air cavities with short-range order. To produce the structures in a simple and reproducible manner, monodisperse silica particles are dispersed in a photocurable resin of poly(ethylene glycol) dimethacrylate (PEGDMA) at a volume fraction of 0.3. The particles spontaneously form the amorphous array with short-range order, which is rapidly captured in polymeric films by photopolymerization of the resin. Selective removal of silica particles from the polymerized resin leaves behind amorphous array of air cavities. The inverse glasses display structural colors with negligible backscattering in blue due to short optical path and low index in each cavity. Therefore, the colors can be tuned in full visible range by simply controlling the cavity size. The photocurable suspensions of silica particles can be patterned by photolithography, which enables the production of freestanding films containing patterned inverse glasses with noniridescent structural colors. PMID:27124719

  4. Visualization of dyed NAPL concentration in transparent porous media using color space components.

    PubMed

    Kashuk, Sina; Mercurio, Sophia R; Iskander, Magued

    2014-07-01

    Finding a correlation between image pixel information and non-aqueous phase liquid (NAPL) saturation is an important issue in bench-scale geo-environmental model studies that employ optical imaging techniques. Another concern is determining the best dye color and its optimum concentration as a tracer for use in mapping NAPL zones. Most bench scale flow studies employ monochromatic gray-scale imaging to analyze the concentration of mostly red dyed NAPL tracers in porous media. However, the use of grayscale utilizes a third of the available information in color images, which typically contain three color-space components. In this study, eight color spaces consisting of 24 color-space components were calibrated against dye concentration for three color-dyes. Additionally, multiple color space components were combined to increase the correlation between color-space data and dyed NAPL concentration. This work is performed to support imaging of NAPL migration in transparent synthetic soils representing the macroscopic behavior of natural soils. The transparent soil used in this study consists of fused quartz and a matched refractive index mineral-oil solution that represents the natural aquifer. The objective is to determine the best color dye concentration and ideal color space components for rendering dyed sucrose-saturated fused quartz that represents contamination of the natural aquifer by a dense NAPL (DNAPL). Calibration was achieved for six NAPL zone lengths using 3456 images (24 color space components×3 dyes×48 NAPL combinations) of contaminants within a defined criteria expressed as peak signal to noise ratio. The effect of data filtering was also considered and a convolution average filter is recommended for image conditioning. The technology presented in this paper is fast, accurate, non-intrusive and inexpensive method for quantifying contamination zones using transparent soil models.

  5. Remote interactive direct volume rendering of AMR data

    SciTech Connect

    Kreylos, Oliver; Weber, Gunther H.; Bethel, E. Wes; Shalf, John M.; Hamann, Bernd; Joy, Kenneth I.

    2002-03-28

    We describe a framework for direct volume rendering of adaptive mesh refinement (AMR) data that operates directly on the hierarchical grid structure, without the need to resample data onto a single, uniform rectilinear grid. The framework can be used for a range of renderers optimized for particular hardware architectures: a hardware-assisted renderer for single-processor graphics workstations, and a massively parallel software-only renderer for supercomputers. It is also possible to use the framework for distributed rendering servers. By exploiting the multiresolution structure of AMR data, the hardware-assisted renderers can render large AMR data sets at interactive rates, even if the data is stored remotely.

  6. Parallel unstructured volume rendering in ParaView

    NASA Astrophysics Data System (ADS)

    Moreland, Kenneth; Avila, Lisa; Fisk, Lee Ann

    2007-01-01

    ParaView is a popular open-source general-purpose scientific visualization application. One of the many visualization tools available within ParaView is the volume rendering of unstructured meshes. Volume rendering is a technique that renders a mesh as a translucent solid, thereby allowing the user to see every point in three-dimensional space simultaneously. Because volume rendering is computationally intensive, ParaView now employs a unique parallel rendering algorithm to speed the processes. The parallel rendering algorithm is very flexible. It works equally well for both volumes and surfaces, and can properly render the intersection of a volume and opaque polygonal surfaces. The parallel rendering algorithm can also render images for tiled displays. In this paper, we explore the implementation of parallel unstructured volume rendering in ParaView.

  7. A rendering approach for stereoscopic web pages

    NASA Astrophysics Data System (ADS)

    Zhang, Jianlong; Wang, Wenmin; Wang, Ronggang; Chen, Qinshui

    2014-03-01

    Web technology provides a relatively easy way to generate contents for us to recognize the world, and with the development of stereoscopic display technology, the stereoscopic devices will become much more popular. The combination of web technology and stereoscopic display technology will bring revolutionary visual effect. The Stereoscopic 3D (S3D) web pages, in which text, image and video may have different depth, can be displayed on stereoscopic display devices. This paper presents the approach about how to render two viewing S3D web pages including text, images, widgets: first, an algorithm should be developed in order to display stereoscopic elements like text, widgets by using 2D graphic library; second, a method should be presented to render stereoscopic web page based on current framework of the browser; third, a rough solution is invented to fix the problem that comes out in the method.

  8. Remote rendering using vtk and vic.

    SciTech Connect

    Olson, R.; Papka, M.E.

    2000-09-19

    This paper presents a remote rendering application that involves the extension of the Visualization Toolkit (vtk) and the Video Conferencing Tool (vie) for use in remote rendering complete with interaction from the remote site using the vie user interface. Vtk is an open source C++ library, with Tel, Python, and Java bindings for computer graphics, image processing, and visualization [3]. Vtk provides a higher level of support, beyond the traditional low-level libraries, for creating visualization applications. Vtk includes algorithms to support the visualization of scalars, vectors, and tensors. Vic is a flexible tool built by Lawrence Berkeley National Laboratory for real-time video conferencing over the Internet [2]. Vie's user interface is built as Tcl/Tk script embedded in the applications. This allows developers to prototype changes to the interface in a simple and straightforward manner.

  9. Color correction optimization with hue regularization

    NASA Astrophysics Data System (ADS)

    Zhang, Heng; Liu, Huaping; Quan, Shuxue

    2011-01-01

    Previous work has suggested that observers are capable of judging the quality of an image without any knowledge of the original scene. When no reference is available, observers can extract the apparent objects in an image and compare them with the typical colors of similar objects recalled from their memories. Some generally agreed upon research results indicate that although perfect colorimetric rendering is not conspicuous and color errors can be well tolerated, the appropriate rendition of certain memory colors such as skin, grass, and sky is an important factor in the overall perceived image quality. These colors are appreciated in a fairly consistent manner and are memorized with slightly different hues and higher color saturation. The aim of color correction for a digital color pipeline is to transform the image data from a device dependent color space to a target color space, usually through a color correction matrix which in its most basic form is optimized through linear regressions between the two sets of data in two color spaces in the sense of minimized Euclidean color error. Unfortunately, this method could result in objectionable distortions if the color error biased certain colors undesirably. In this paper, we propose a color correction optimization method with preferred color reproduction in mind through hue regularization and present some experimental results.

  10. Colorful Chemistry.

    ERIC Educational Resources Information Center

    Williams, Suzanne

    1991-01-01

    Described is an color-making activity where students use food coloring, eyedroppers, and water to make various colored solutions. Included are the needed materials and procedures. Students are asked to write up the formulas for making their favorite color. (KR)

  11. How colorful! A feature it is, isn't it?

    NASA Astrophysics Data System (ADS)

    Lebowsky, Fritz

    2015-01-01

    A display's color subpixel geometry provides an intriguing opportunity for improving readability of text. True type fonts can be positioned at the precision of subpixel resolution. With such a constraint in mind, how does one need to design font characteristics? On the other hand, display manufactures try hard in addressing the color display's dilemma: smaller pixel pitch and larger display diagonals strongly increase the total number of pixels. Consequently, cost of column and row drivers as well as power consumption increase. Perceptual color subpixel rendering using color component subsampling may save about 1/3 of color subpixels (and reduce power dissipation). This talk will try to elaborate the following questions, based on simulation of several different layouts of subpixel matrices: Up to what level are display device constraints compatible with software specific ideas of rendering text? How much of color contrast will remain? How to best consider preferred viewing distance for readability of text? How much does visual acuity vary at 20/20 vision? Can simplified models of human visual color perception be easily applied to text rendering on displays? How linear is human visual contrast perception around band limit of a display's spatial resolution? How colorful does the rendered text appear on the screen? How much does viewing angle influence the performance of subpixel layouts and color subpixel rendering?

  12. Solid-state lamps with optimized color saturation ability.

    PubMed

    Zukauskas, Artūras; Vaicekauskas, Rimantas; Shur, Michael

    2010-02-01

    Spectral power distribution of trichromatic clusters of light-emitting diodes (LEDs) was optimized for rendering the highest number of colors with a perceptually noticeable gain in chroma (color saturation) out of 1269 Munsell samples. The basic tradeoffs of the number of colors rendered with increased saturation with the number of colors rendered with high fidelity and with luminous efficacy of radiation were established. High-saturation RGB clusters composed of commercially available AlGaInP and InGaN LEDs were modeled for a standard set of correlated color temperatures and the stability of the color saturation ability of the clusters against the drift of peak wavelengths was investigated. PMID:20174057

  13. A Multiresolution Image Cache for Volume Rendering

    SciTech Connect

    LaMar, E; Pascucci, V

    2003-02-27

    The authors discuss the techniques and implementation details of the shared-memory image caching system for volume visualization and iso-surface rendering. One of the goals of the system is to decouple image generation from image display. This is done by maintaining a set of impostors for interactive display while the production of the impostor imagery is performed by a set of parallel, background processes. The system introduces a caching basis that is free of the gap/overlap artifacts of earlier caching techniques. instead of placing impostors at fixed, pre-defined positions in world space, the technique is to adaptively place impostors relative to the camera viewpoint. The positions translate with the camera but stay aligned to the data; i.e., the positions translate, but do not rotate, with the camera. The viewing transformation is factored into a translation transformation and a rotation transformation. The impostor imagery is generated using just the translation transformation and visible impostors are displayed using just the rotation transformation. Displayed image quality is improved by increasing the number of impostors and the frequency that impostors are re-rendering is improved by decreasing the number of impostors.

  14. 'Burns Cliff' Color Panorama

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site] Click on the image for 'Burns Cliff' Color Panorama (QTVR)

    NASA's Mars Exploration Rover Opportunity captured this view of 'Burns Cliff' after driving right to the base of this southeastern portion of the inner wall of 'Endurance Crater.' The view combines frames taken by Opportunity's panoramic camera between the rover's 287th and 294th martian days (Nov. 13 to 20, 2004).

    This is a composite of 46 different images, each acquired in seven different Pancam filters. It is an approximately true-color rendering generated from the panoramic camera's 750-nanometer, 530-nanometer and 430-nanometer filters. The mosaic spans more than 180 degrees side to side. Because of this wide-angle view, the cliff walls appear to bulge out toward the camera. In reality the walls form a gently curving, continuous surface.

  15. A multi-zoned white organic light-emitting diode with high CRI and low color temperature

    PubMed Central

    Zhang, Tao; He, Shou-Jie; Wang, Deng-Ke; Jiang, Nan; Lu, Zheng-Hong

    2016-01-01

    White organic light emitting diodes (WOLEDs) is becoming a new platform technology for a range of applications such as flat-panel displays, solid-state lightings etc., and are under intensive research. For general solid-state illumination applications, a WOLED’s color rendering index (CRI) and correlated color temperature (CCT) are two crucial parameters. This paper reports that WOLED device structures can be constructed using four stacked emission layers which independently emit lights at blue, green, yellow and red color respectively. The intensity of each emission layer is then engineered by funneling excitons to the targeted emission layer to achieve an ultrahigh 92 CRI at 5000 cd/m2, and to reduce CCT to below 2500 K. PMID:26842934

  16. A multi-zoned white organic light-emitting diode with high CRI and low color temperature

    NASA Astrophysics Data System (ADS)

    Zhang, Tao; He, Shou-Jie; Wang, Deng-Ke; Jiang, Nan; Lu, Zheng-Hong

    2016-02-01

    White organic light emitting diodes (WOLEDs) is becoming a new platform technology for a range of applications such as flat-panel displays, solid-state lightings etc., and are under intensive research. For general solid-state illumination applications, a WOLED’s color rendering index (CRI) and correlated color temperature (CCT) are two crucial parameters. This paper reports that WOLED device structures can be constructed using four stacked emission layers which independently emit lights at blue, green, yellow and red color respectively. The intensity of each emission layer is then engineered by funneling excitons to the targeted emission layer to achieve an ultrahigh 92 CRI at 5000 cd/m2, and to reduce CCT to below 2500 K.

  17. A multi-zoned white organic light-emitting diode with high CRI and low color temperature.

    PubMed

    Zhang, Tao; He, Shou-Jie; Wang, Deng-Ke; Jiang, Nan; Lu, Zheng-Hong

    2016-02-04

    White organic light emitting diodes (WOLEDs) is becoming a new platform technology for a range of applications such as flat-panel displays, solid-state lightings etc., and are under intensive research. For general solid-state illumination applications, a WOLED's color rendering index (CRI) and correlated color temperature (CCT) are two crucial parameters. This paper reports that WOLED device structures can be constructed using four stacked emission layers which independently emit lights at blue, green, yellow and red color respectively. The intensity of each emission layer is then engineered by funneling excitons to the targeted emission layer to achieve an ultrahigh 92 CRI at 5000 cd/m(2), and to reduce CCT to below 2500 K.

  18. Uncalibrated color

    NASA Astrophysics Data System (ADS)

    Moroney, Nathan

    2006-01-01

    Color calibration or the use of color measurement processes to characterize the color properties of a device or workflow is often expected or assumed for many color reproduction applications. However it is interesting to consider applications or situations in which color calibration is not as critical. In the first case it is possible to imagine an implicit color calibration resulting from a standardization or convergence of the colorant and substrate spectrum. In the second case it is possible to imagine cases where the device color variability is significantly less than the user color thresholds or expectations for color consistency. There are still general requirements for this form of pragmatic color but they are generally lower than for the higher end of digital color reproduction. Finally it is possible to imagine an implicit calibration that leverages in some way the highly accurate memory color for the hue of common objects. This scenario culminates with a challenge to create a natural capture calibration standard that does not require individual calibration, is spectrally diverse, is inexpensive and is environmentally friendly.

  19. Color realism and color science.

    PubMed

    Byrne, Alex; Hilbert, David R

    2003-02-01

    The target article is an attempt to make some progress on the problem of color realism. Are objects colored? And what is the nature of the color properties? We defend the view that physical objects (for instance, tomatoes, radishes, and rubies) are colored, and that colors are physical properties, specifically, types of reflectance. This is probably a minority opinion, at least among color scientists. Textbooks frequently claim that physical objects are not colored, and that the colors are "subjective" or "in the mind." The article has two other purposes: First, to introduce an interdisciplinary audience to some distinctively philosophical tools that are useful in tackling the problem of color realism and, second, to clarify the various positions and central arguments in the debate. The first part explains the problem of color realism and makes some useful distinctions. These distinctions are then used to expose various confusions that often prevent people from seeing that the issues are genuine and difficult, and that the problem of color realism ought to be of interest to anyone working in the field of color science. The second part explains the various leading answers to the problem of color realism, and (briefly) argues that all views other than our own have serious difficulties or are unmotivated. The third part explains and motivates our own view, that colors are types of reflectances and defends it against objections made in the recent literature that are often taken as fatal.

  20. Color realism and color science.

    PubMed

    Byrne, Alex; Hilbert, David R

    2003-02-01

    The target article is an attempt to make some progress on the problem of color realism. Are objects colored? And what is the nature of the color properties? We defend the view that physical objects (for instance, tomatoes, radishes, and rubies) are colored, and that colors are physical properties, specifically, types of reflectance. This is probably a minority opinion, at least among color scientists. Textbooks frequently claim that physical objects are not colored, and that the colors are "subjective" or "in the mind." The article has two other purposes: First, to introduce an interdisciplinary audience to some distinctively philosophical tools that are useful in tackling the problem of color realism and, second, to clarify the various positions and central arguments in the debate. The first part explains the problem of color realism and makes some useful distinctions. These distinctions are then used to expose various confusions that often prevent people from seeing that the issues are genuine and difficult, and that the problem of color realism ought to be of interest to anyone working in the field of color science. The second part explains the various leading answers to the problem of color realism, and (briefly) argues that all views other than our own have serious difficulties or are unmotivated. The third part explains and motivates our own view, that colors are types of reflectances and defends it against objections made in the recent literature that are often taken as fatal. PMID:14598439

  1. Immersive volume rendering of blood vessels

    NASA Astrophysics Data System (ADS)

    Long, Gregory; Kim, Han Suk; Marsden, Alison; Bazilevs, Yuri; Schulze, Jürgen P.

    2012-03-01

    In this paper, we present a novel method of visualizing flow in blood vessels. Our approach reads unstructured tetrahedral data, resamples it, and uses slice based 3D texture volume rendering. Due to the sparse structure of blood vessels, we utilize an octree to efficiently store the resampled data by discarding empty regions of the volume. We use animation to convey time series data, wireframe surface to give structure, and utilize the StarCAVE, a 3D virtual reality environment, to add a fully immersive element to the visualization. Our tool has great value in interdisciplinary work, helping scientists collaborate with clinicians, by improving the understanding of blood flow simulations. Full immersion in the flow field allows for a more intuitive understanding of the flow phenomena, and can be a great help to medical experts for treatment planning.

  2. Seeing Color

    ERIC Educational Resources Information Center

    Texley, Juliana

    2005-01-01

    Colors are powerful tools for engaging children, from the youngest years onward. We hang brightly patterned mobiles above their cribs and help them learn the names of colors as they begin to record their own ideas in pictures and words. Colors can also open the door to an invisible world of electromagnetism, even when children can barely imagine…

  3. Resolution-independent surface rendering using programmable graphics hardware

    DOEpatents

    Loop, Charles T.; Blinn, James Frederick

    2008-12-16

    Surfaces defined by a Bezier tetrahedron, and in particular quadric surfaces, are rendered on programmable graphics hardware. Pixels are rendered through triangular sides of the tetrahedra and locations on the shapes, as well as surface normals for lighting evaluations, are computed using pixel shader computations. Additionally, vertex shaders are used to aid interpolation over a small number of values as input to the pixel shaders. Through this, rendering of the surfaces is performed independently of viewing resolution, allowing for advanced level-of-detail management. By individually rendering tetrahedrally-defined surfaces which together form complex shapes, the complex shapes can be rendered in their entirety.

  4. Pet fur color and texture classification

    NASA Astrophysics Data System (ADS)

    Yen, Jonathan; Mukherjee, Debarghar; Lim, SukHwan; Tretter, Daniel

    2007-01-01

    Object segmentation is important in image analysis for imaging tasks such as image rendering and image retrieval. Pet owners have been known to be quite vocal about how important it is to render their pets perfectly. We present here an algorithm for pet (mammal) fur color classification and an algorithm for pet (animal) fur texture classification. Per fur color classification can be applied as a necessary condition for identifying the regions in an image that may contain pets much like the skin tone classification for human flesh detection. As a result of the evolution, fur coloration of all mammals is caused by a natural organic pigment called Melanin and Melanin has only very limited color ranges. We have conducted a statistical analysis and concluded that mammal fur colors can be only in levels of gray or in two colors after the proper color quantization. This pet fur color classification algorithm has been applied for peteye detection. We also present here an algorithm for animal fur texture classification using the recently developed multi-resolution directional sub-band Contourlet transform. The experimental results are very promising as these transforms can identify regions of an image that may contain fur of mammals, scale of reptiles and feather of birds, etc. Combining the color and texture classification, one can have a set of strong classifiers for identifying possible animals in an image.

  5. Does correlated color temperature affect the ability of humans to identify veins?

    PubMed

    Argyraki, Aikaterini; Clemmensen, Line Katrine Harder; Petersen, Paul Michael

    2016-01-01

    In the present study we provide empirical evidence and demonstrate statistically that white illumination settings can affect the human ability to identify veins in the inner hand vasculature. A special light-emitting diode lamp with high color rendering index (CRI 84-95) was developed and the effect of correlated color temperature was evaluated, in the range between 2600 and 5700 K at an illuminance of 40±9  lx on the ability of adult humans to identify veins. It is shown that the ability to identify veins can, on average, be increased up to 24% when white illumination settings that do not resemble incandescent light are applied. The illuminance reported together with the effect of white illumination settings on direct visual perception of biosamples are relevant for clinical investigations during the night. PMID:26831595

  6. Color Terms and Color Concepts

    ERIC Educational Resources Information Center

    Davidoff, Jules

    2006-01-01

    In their lead articles, both Kowalski and Zimiles (2006) and O'Hanlon and Roberson (2006) declare a general relation between color term knowledge and the ability to conceptually represent color. Kowalski and Zimiles, in particular, argue for a priority for the conceptual representation in color term acquisition. The complexities of the interaction…

  7. Color Categories and Color Appearance

    ERIC Educational Resources Information Center

    Webster, Michael A.; Kay, Paul

    2012-01-01

    We examined categorical effects in color appearance in two tasks, which in part differed in the extent to which color naming was explicitly required for the response. In one, we measured the effects of color differences on perceptual grouping for hues that spanned the blue-green boundary, to test whether chromatic differences across the boundary…

  8. Photo-real rendering of bioluminescence and iridescence in creatures from the abyss

    NASA Astrophysics Data System (ADS)

    Prusten, Mark

    2008-08-01

    The generation of photo-real renderings of bioluminescence is developed for creatures from the abyss. Bioluminescence results from a chemical reaction with examples found in deep-sea marine environments including: algae, copepods, jellyfish, squid, and fish. In bioluminescence, the excitation energy is supplied by a chemical reaction, not by a source of light. The greatest transparency window in seawater is in the blue region of the visible spectrum. From small creatures like single-cell algae, to large species of siphonophore Praya dubia (40m), luminescent phenomena can be produced by mechanical excitement from disturbances of objects passing by. Deep sea fish, like the Pacific Black Dragonfish are covered with photophores along the upper and lower surfaces which emits light when disturbed. Other animals like small squids have several different types of light organs oscillating at different rates. Custom shaders and material phenomena incorporate indirect lighting like: global illumination, final gathering, ambient occlusion and subsurface scattering to provide photo real images. Species like the Hydomedusae jellyfish, produce colors that are also generated by iridescence of thin tissues. The modeling and rendering of these tissues requires thin film multilayer stacks. These phenomena are simulated by semi-rigid body dynamics in a procedural animation environment. These techniques have been applied to develop spectral rendering of scenes outside the normal visible window in typical computer animation render engines.

  9. Lighting design for globally illuminated volume rendering.

    PubMed

    Zhang, Yubo; Ma, Kwan-Liu

    2013-12-01

    With the evolution of graphics hardware, high quality global illumination becomes available for real-time volume rendering. Compared to local illumination, global illumination can produce realistic shading effects which are closer to real world scenes, and has proven useful for enhancing volume data visualization to enable better depth and shape perception. However, setting up optimal lighting could be a nontrivial task for average users. There were lighting design works for volume visualization but they did not consider global light transportation. In this paper, we present a lighting design method for volume visualization employing global illumination. The resulting system takes into account view and transfer-function dependent content of the volume data to automatically generate an optimized three-point lighting environment. Our method fully exploits the back light which is not used by previous volume visualization systems. By also including global shadow and multiple scattering, our lighting system can effectively enhance the depth and shape perception of volumetric features of interest. In addition, we propose an automatic tone mapping operator which recovers visual details from overexposed areas while maintaining sufficient contrast in the dark areas. We show that our method is effective for visualizing volume datasets with complex structures. The structural information is more clearly and correctly presented under the automatically generated light sources.

  10. Direct volume rendering methods for cell structures.

    PubMed

    Martišek, Dalibor; Martišek, Karel

    2012-01-01

    The study of the complicated architecture of cell space structures is an important problem in biology and medical research. Optical cuts of cells produced by confocal microscopes enable two-dimensional (2D) and three-dimensional (3D) reconstructions of observed cells. This paper discuses new possibilities for direct volume rendering of these data. We often encounter 16 or more bit images in confocal microscopy of cells. Most of the information contained in these images is unsubstantial for the human vision. Therefore, it is necessary to use mathematical algorithms for visualization of such images. Present software tools as OpenGL or DirectX run quickly in graphic station with special graphic cards, run very unsatisfactory on PC without these cards and outputs are usually poor for real data. These tools are black boxes for a common user and make it impossible to correct and improve them. With the method proposed, more parameters of the environment can be set, making it possible to apply 3D filters to set the output image sharpness in relation to the noise. The quality of the output is incomparable to the earlier described methods and is worth increasing the computing time. We would like to offer mathematical methods of 3D scalar data visualization describing new algorithms that run on standard PCs very well. PMID:22511504

  11. Color Analysis

    NASA Astrophysics Data System (ADS)

    Wrolstad, Ronald E.; Smith, Daniel E.

    Color, flavor, and texture are the three principal quality attributes that determine food acceptance, and color has a far greater influence on our judgment than most of us appreciate. We use color to determine if a banana is at our preferred ripeness level, and a discolored meat product can warn us that the product may be spoiled. The marketing departments of our food corporations know that, for their customers, the color must be "right." The University of California Davis scorecard for wine quality designates four points out of 20, or 20% of the total score, for color and appearance (1). Food scientists who establish quality control specifications for their product are very aware of the importance of color and appearance. While subjective visual assessment and use of visual color standards are still used in the food industry, instrumental color measurements are extensively employed. Objective measurement of color is desirable for both research and industrial applications, and the ruggedness, stability, and ease of use of today's color measurement instruments have resulted in their widespread adoption.

  12. Color categories and color appearance

    PubMed Central

    Webster, Michael A.; Kay, Paul

    2011-01-01

    We examined categorical effects in color appearance in two tasks, which in part differed in the extent to which color naming was explicitly required for the response. In one, we measured the effects of color differences on perceptual grouping for hues that spanned the blue–green boundary, to test whether chromatic differences across the boundary were perceptually exaggerated. This task did not require overt judgments of the perceived colors, and the tendency to group showed only a weak and inconsistent categorical bias. In a second case, we analyzed results from two prior studies of hue scaling of chromatic stimuli (De Valois, De Valois, Switkes, & Mahon, 1997; Malkoc, Kay, & Webster, 2005), to test whether color appearance changed more rapidly around the blue–green boundary. In this task observers directly judge the perceived color of the stimuli and these judgments tended to show much stronger categorical effects. The differences between these tasks could arise either because different signals mediate color grouping and color appearance, or because linguistic categories might differentially intrude on the response to color and/or on the perception of color. Our results suggest that the interaction between language and color processing may be highly dependent on the specific task and cognitive demands and strategies of the observer, and also highlight pronounced individual differences in the tendency to exhibit categorical responses. PMID:22176751

  13. Processing of Color Words Activates Color Representations

    ERIC Educational Resources Information Center

    Richter, Tobias; Zwaan, Rolf A.

    2009-01-01

    Two experiments were conducted to investigate whether color representations are routinely activated when color words are processed. Congruency effects of colors and color words were observed in both directions. Lexical decisions on color words were faster when preceding colors matched the color named by the word. Color-discrimination responses…

  14. Biomimetics, color, and the arts

    NASA Astrophysics Data System (ADS)

    Schenk, Franziska

    2015-03-01

    Color as dramatic, dynamic and dazzling as the iridescent hues on the wings of certain butterflies has never been encountered in the art world. Unlike and unmatched by the chemical pigments of the artists' palette, this changeable color is created by transparent, colorless nanostructures that, as with prisms, diffract and reflect light to render spectral color visible. Until now, iridescent colors, by their very nature, have defied artists' best efforts to fully capture these rainbow hues. Now, for the first time, the artist and researcher Franziska Schenk employs latest nature-inspired color-shift technology to actually simulate the iridescence of butterflies and beetles on canvas. Crucially, studying the ingenious ways in which a range of such displays are created by insects has provided the artist with vital clues on how to adapt and adopt these challenging optical nano-materials for painting. And indeed, after years of meticulous and painstaking research both in the lab and studio, the desired effect is achieved. The resulting paintings, like an iridescent insect, do in fact fluctuate in perceived color - depending on the light and viewing angle. In tracing the artist's respective biomimetic approach, the paper not only provides an insight into the new color technology's evolution and innovative artistic possibilities, but also suggests what artists can learn from nature.

  15. Design for a real-time high-quality volume-rendering work station

    SciTech Connect

    Levoy, M.

    1989-05-01

    A design is presented for a workstation capable of rendering arbitrary mixtures of analytically defined geometry and sampled scalar fields of three spatial dimensions in real-time or near real-time. The design is based on volumetric compositing, a relatively new approach to visualizing scalar fields by computing 2D projections of a colored semi-transparent volume. Geometric primitives are added by filtering and 3D scan-converting them into the data set prior to rendering. Speedups totaling four orders of magnitude over published volumetric compositing techniques are obtained through a combination of algorithmic improvements and hardware implementation of Pixel-planes 5, a massively parallel raster display engine incorporating custom logic-enhanced memory chips. A preliminary design is also presented for a two-handed volume-of-interest data exploration tool.

  16. [Hair colorants].

    PubMed

    Urbanek-Karłowska, B; Luks, E; Jedra, M; Kiss, E; Malanowska, M

    1997-01-01

    The properties, mode of action and its duration of the preparations used for hair dyeing are described, together with their chemical components, and also preparations of herbal origin. The chemical reactions are described in detail which lead the development of a color polymer occurring during hair dyeing. The studies are presented which are used for toxicological assessment of the raw materials which are the components of the colorants, and the list is included of hair colorants permitted for use in Poland. PMID:9562811

  17. 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.

  18. Polar Color

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 3 May 2004 This nighttime visible color image was collected on January 1, 2003 during the Northern Summer season near the North Polar Troughs.

    This daytime visible color image was collected on September 4, 2002 during the Northern Spring season in Vastitas Borealis. The THEMIS VIS camera is capable of capturing color images of the martian surface using its five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from the use of multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.

    Image information: VIS instrument. Latitude 79, Longitude 346 East (14 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with

  19. Quantum Color

    ScienceCinema

    Lincoln, Don

    2016-07-20

    The idea of electric charges and electricity in general is a familiar one to the science savvy viewer. However, electromagnetism is but one of the four fundamental forces and not the strongest one. The strongest of the fundamental forces is called the strong nuclear force and it has its own associated charge. Physicists call this charge “color” in analogy with the primary colors, although there is no real connection with actual color. In this video, Fermilab’s Dr. Don Lincoln explains why it is that we live in a colorful world.

  20. Beyond the Renderer: Software Architecture for Parallel Graphics and Visualization

    NASA Technical Reports Server (NTRS)

    Crockett, Thomas W.

    1996-01-01

    As numerous implementations have demonstrated, software-based parallel rendering is an effective way to obtain the needed computational power for a variety of challenging applications in computer graphics and scientific visualization. To fully realize their potential, however, parallel renderers need to be integrated into a complete environment for generating, manipulating, and delivering visual data. We examine the structure and components of such an environment, including the programming and user interfaces, rendering engines, and image delivery systems. We consider some of the constraints imposed by real-world applications and discuss the problems and issues involved in bringing parallel rendering out of the lab and into production.

  1. DOE CALiPER Program, Report 20.1 Subjective Evaluation of Beam Quality, Shadow Quality, and Color Quality for LED PAR38 Lamps

    SciTech Connect

    Royer, Michael P.; Poplawski, Michael E.; Miller, Naomi J.

    2013-10-01

    This report focuses on human-evaluated characteristics, including beam quality, shadow quality, and color quality. Using a questionnaire that included rank ordering, opinions on 27 of the Report 20 PAR38 lamps were gathered during a demonstration event for members of the local Illuminating Engineering Society (IES) chapter. This was not a rigorous scientific experiment, and the data should not be extrapolated beyond the scope of the demonstration. The results suggest that many of the LED products compared favorably to halogen PAR38 benchmarks in all attributes considered. LED lamps using a single-emitter design were generally preferred for their beam quality and shadow quality, and the IES members ranking of color quality did not always match the rank according to the color rendering index (CRI).

  2. CALiPER Report 20.1: Subjective Evaluation of Beam Quality, Shadow Quality, and Color Quality for LED PAR38 Lamps

    SciTech Connect

    None, None

    2013-11-07

    This report focuses on human-evaluated characteristics, including beam quality, shadow quality, and color quality. Using a questionnaire that included rank-ordering, opinions on 27 of the Report 20 PAR38 lamps were gathered during a demonstration event for members of the local Illuminating Engineering Society (IES) chapter. This was not a rigorous scientific experiment, and the data should not be extrapolated beyond the scope of the demonstration. The results suggest that many of the LED products compared favorably to halogen PAR38 benchmarks in all attributes considered. LED lamps using a single-emitter design were generally preferred for their beam quality and shadow quality, and the IES members' ranking of color quality did not always match the rank according to the color rendering index (CRI).

  3. Color accuracy and reproducibility in whole slide imaging scanners

    PubMed Central

    Shrestha, Prarthana; Hulsken, Bas

    2014-01-01

    Abstract We propose a workflow for color reproduction in whole slide imaging (WSI) scanners, such that the colors in the scanned images match to the actual slide color and the inter-scanner variation is minimum. We describe a new method of preparation and verification of the color phantom slide, consisting of a standard IT8-target transmissive film, which is used in color calibrating and profiling the WSI scanner. We explore several International Color Consortium (ICC) compliant techniques in color calibration/profiling and rendering intents for translating the scanner specific colors to the standard display (sRGB) color space. Based on the quality of the color reproduction in histopathology slides, we propose the matrix-based calibration/profiling and absolute colorimetric rendering approach. The main advantage of the proposed workflow is that it is compliant to the ICC standard, applicable to color management systems in different platforms, and involves no external color measurement devices. We quantify color difference using the CIE-DeltaE2000 metric, where DeltaE values below 1 are considered imperceptible. Our evaluation on 14 phantom slides, manufactured according to the proposed method, shows an average inter-slide color difference below 1 DeltaE. The proposed workflow is implemented and evaluated in 35 WSI scanners developed at Philips, called the Ultra Fast Scanners (UFS). The color accuracy, measured as DeltaE between the scanner reproduced colors and the reference colorimetric values of the phantom patches, is improved on average to 3.5 DeltaE in calibrated scanners from 10 DeltaE in uncalibrated scanners. The average inter-scanner color difference is found to be 1.2 DeltaE. The improvement in color performance upon using the proposed method is apparent with the visual color quality of the tissue scans. PMID:26158041

  4. Realistic Real-Time Outdoor Rendering in Augmented Reality

    PubMed Central

    Kolivand, Hoshang; Sunar, Mohd Shahrizal

    2014-01-01

    Realistic rendering techniques of outdoor Augmented Reality (AR) has been an attractive topic since the last two decades considering the sizeable amount of publications in computer graphics. Realistic virtual objects in outdoor rendering AR systems require sophisticated effects such as: shadows, daylight and interactions between sky colours and virtual as well as real objects. A few realistic rendering techniques have been designed to overcome this obstacle, most of which are related to non real-time rendering. However, the problem still remains, especially in outdoor rendering. This paper proposed a much newer, unique technique to achieve realistic real-time outdoor rendering, while taking into account the interaction between sky colours and objects in AR systems with respect to shadows in any specific location, date and time. This approach involves three main phases, which cover different outdoor AR rendering requirements. Firstly, sky colour was generated with respect to the position of the sun. Second step involves the shadow generation algorithm, Z-Partitioning: Gaussian and Fog Shadow Maps (Z-GaF Shadow Maps). Lastly, a technique to integrate sky colours and shadows through its effects on virtual objects in the AR system, is introduced. The experimental results reveal that the proposed technique has significantly improved the realism of real-time outdoor AR rendering, thus solving the problem of realistic AR systems. PMID:25268480

  5. Method of producing hydrogen, and rendering a contaminated biomass inert

    DOEpatents

    Bingham, Dennis N [Idaho Falls, ID; Klingler, Kerry M [Idaho Falls, ID; Wilding, Bruce M [Idaho Falls, ID

    2010-02-23

    A method for rendering a contaminated biomass inert includes providing a first composition, providing a second composition, reacting the first and second compositions together to form an alkaline hydroxide, providing a contaminated biomass feedstock and reacting the alkaline hydroxide with the contaminated biomass feedstock to render the contaminated biomass feedstock inert and further producing hydrogen gas, and a byproduct that includes the first composition.

  6. 7 CFR 54.15 - Advance information concerning service rendered.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Advance information concerning service rendered. 54.15... Service § 54.15 Advance information concerning service rendered. Upon request of any applicant, all or any... SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED)...

  7. 18 CFR 1308.17 - Failure to render timely decision.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Failure to render timely decision. 1308.17 Section 1308.17 Conservation of Power and Water Resources TENNESSEE VALLEY AUTHORITY CONTRACT DISPUTES Contracting Officers § 1308.17 Failure to render timely decision. Any failure...

  8. Realistic real-time outdoor rendering in augmented reality.

    PubMed

    Kolivand, Hoshang; Sunar, Mohd Shahrizal

    2014-01-01

    Realistic rendering techniques of outdoor Augmented Reality (AR) has been an attractive topic since the last two decades considering the sizeable amount of publications in computer graphics. Realistic virtual objects in outdoor rendering AR systems require sophisticated effects such as: shadows, daylight and interactions between sky colours and virtual as well as real objects. A few realistic rendering techniques have been designed to overcome this obstacle, most of which are related to non real-time rendering. However, the problem still remains, especially in outdoor rendering. This paper proposed a much newer, unique technique to achieve realistic real-time outdoor rendering, while taking into account the interaction between sky colours and objects in AR systems with respect to shadows in any specific location, date and time. This approach involves three main phases, which cover different outdoor AR rendering requirements. Firstly, sky colour was generated with respect to the position of the sun. Second step involves the shadow generation algorithm, Z-Partitioning: Gaussian and Fog Shadow Maps (Z-GaF Shadow Maps). Lastly, a technique to integrate sky colours and shadows through its effects on virtual objects in the AR system, is introduced. The experimental results reveal that the proposed technique has significantly improved the realism of real-time outdoor AR rendering, thus solving the problem of realistic AR systems.

  9. Color Blind or Color Conscious?

    ERIC Educational Resources Information Center

    Tatum, Beverly Daniel

    1999-01-01

    A color-blind approach often signifies that an educator has not considered what racial/ethnic identity means to youngsters. Students want to find themselves reflected in the faces of teachers and other students. Color-conscious teachers seek out materials that positively reflect students' identities and initiate discussions about race and racism.…

  10. Local and Global Illumination in the Volume Rendering Integral

    SciTech Connect

    Max, N; Chen, M

    2005-10-21

    This article is intended as an update of the major survey by Max [1] on optical models for direct volume rendering. It provides a brief overview of the subject scope covered by [1], and brings recent developments, such as new shadow algorithms and refraction rendering, into the perspective. In particular, we examine three fundamentals aspects of direct volume rendering, namely the volume rendering integral, local illumination models and global illumination models, in a wavelength-independent manner. We review the developments on spectral volume rendering, in which visible light are considered as a form of electromagnetic radiation, optical models are implemented in conjunction with representations of spectral power distribution. This survey can provide a basis for, and encourage, new efforts for developing and using complex illumination models to achieve better realism and perception through optical correctness.

  11. Color back projection for fruit maturity evaluation

    NASA Astrophysics Data System (ADS)

    Zhang, Dong; Lee, Dah-Jye; Desai, Alok

    2013-12-01

    In general, fruits and vegetables such as tomatoes and dates are harvested before they fully ripen. After harvesting, they continue to ripen and their color changes. Color is a good indicator of fruit maturity. For example, tomatoes change color from dark green to light green and then pink, light red, and dark red. Assessing tomato maturity helps maximize its shelf life. Color is used to determine the length of time the tomatoes can be transported. Medjool dates change color from green to yellow, and the orange, light red and dark red. Assessing date maturity helps determine the length of drying process to help ripen the dates. Color evaluation is an important step in the processing and inventory control of fruits and vegetables that directly affects profitability. This paper presents an efficient color back projection and image processing technique that is designed specifically for real-time maturity evaluation of fruits. This color processing method requires very simple training procedure to obtain the frequencies of colors that appear in each maturity stage. This color statistics is used to back project colors to predefined color indexes. Fruit maturity is then evaluated by analyzing the reprojected color indexes. This method has been implemented and used for commercial production.

  12. Wavelength dependence of colorimetric properties of lighting sources based on multi-color LEDs.

    PubMed

    Li, Hongtao; Mao, Xianglong; Han, Yanjun; Luo, Yi

    2013-02-11

    Taking color quality scale (CQS) as color rendering assessment criterion, the parameters including each color LED's peak wavelength λi and fractional radiant flux Ii are optimized using genetic algorithm to maximize the luminous efficacy of radiation (LER) of the spectral power distributions (SPDs) of multi-color white light source with 3 to 7 components while maintaining the deviation of its color and color-rendering capability from that of the reference light source within the specified scope. Then the wavelength dependence of these SPDs is analyzed. It is shown that to achieve a Q(a) greater than 95 (5-color LEDs) or even close to 100 (7-color LEDs), the spectral energy could be concentrated in the range of 410~675 nm, indicating that this wavelength range makes a major contribution to high color rendering properties. Spectra filtering experiments show that spectrum around 580nm is harmful to color rendering. To obtain a white light source composed of 3-color LEDs with CQS Q(a) ≥ 80 and correlated color temperature (CCT) within 2700-6500K, the energy ratios among 410-495nm, 495-595nm, and 595-675nm intervals, can be simplified as that of the reference source with the same CCT.

  13. New approach of color image quantization based on multidimensional directory

    NASA Astrophysics Data System (ADS)

    Chang, Chin-Chen; Su, Yuan-Yuan

    2003-04-01

    Color image quantization is a strategy in which a smaller number of colors are used to represent the image. The objective is to make the quality approximate as closely to the original true-color image. The technology is widely used in non-true-color displays and in color printers that cannot reproduce a large number of different colors. However, the main problem the quantization of color image has to face is how to use less colors to show the color image. Therefore, it is very important to choose one suitable palette for an index color image. In this paper, we shall propose a new approach which employs the concept of Multi-Dimensional Directory (MDD) together with the one cycle LBG algorithm to create a high-quality index color image. Compared with the approaches such as VQ, ISQ, and Photoshop v.5, our approach can not only acquire high quality image but also shorten the operation time.

  14. Order-of-magnitude faster isosurface rendering in software on a PC than using dedicated general-purpose rendering hardware

    NASA Astrophysics Data System (ADS)

    Grevera, George J.; Udupa, Jayaram K.; Odhner, Dewey

    1999-05-01

    The purpose of this work is to compare the speed of isosurface rendering in software with that using dedicated hardware. Input data consists of 10 different objects form various parts of the body and various modalities with a variety of surface sizes and shapes. The software rendering technique consists of a particular method of voxel-based surface rendering, called shell rendering. The hardware method is OpenGL-based and uses the surfaces constructed from our implementation of the 'Marching Cubes' algorithm. The hardware environment consists of a variety of platforms including a Sun Ultra I with a Creator3D graphics card and a Silicon Graphics Reality Engine II, both with polygon rendering hardware, and a 300Mhz Pentium PC. The results indicate that the software method was 18 to 31 times faster than any hardware rendering methods. This work demonstrates that a software implementation of a particular rendering algorithm can outperform dedicated hardware. We conclude that for medical surface visualization, expensive dedicated hardware engines are not required. More importantly, available software algorithms on a 300Mhz Pentium PC outperform the speed of rendering via hardware engines by a factor of 18 to 31.

  15. Bio-inspired color image enhancement

    NASA Astrophysics Data System (ADS)

    Meylan, Laurence; Susstrunk, Sabine

    2004-06-01

    Capturing and rendering an image that fulfills the observer's expectations is a difficult task. This is due to the fact that the signal reaching the eye is processed by a complex mechanism before forming a percept, whereas a capturing device only retains the physical value of light intensities. It is especially difficult to render complex scenes with highly varying luminances. For example, a picture taken inside a room where objects are visible through the windows will not be rendered correctly by a global technique. Either details in the dim room will be hidden in shadow or the objects viewed through the window will be too bright. The image has to be treated locally to resemble more closely to what the observer remembers. The purpose of this work is to develop a technique for rendering images based on human local adaptation. We take inspiration from a model of color vision called Retinex. This model determines the perceived color given spatial relationships of the captured signals. Retinex has been used as a computational model for image rendering. In this article, we propose a new solution inspired by Retinex that is based on a single filter applied to the luminance channel. All parameters are image-dependent so that the process requires no parameter tuning. That makes the method more flexible than other existing ones. The presented results show that our method suitably enhances high dynamic range images.

  16. Color vision.

    PubMed

    Gegenfurtner, Karl R; Kiper, Daniel C

    2003-01-01

    Color vision starts with the absorption of light in the retinal cone photoreceptors, which transduce electromagnetic energy into electrical voltages. These voltages are transformed into action potentials by a complicated network of cells in the retina. The information is sent to the visual cortex via the lateral geniculate nucleus (LGN) in three separate color-opponent channels that have been characterized psychophysically, physiologically, and computationally. The properties of cells in the retina and LGN account for a surprisingly large body of psychophysical literature. This suggests that several fundamental computations involved in color perception occur at early levels of processing. In the cortex, information from the three retino-geniculate channels is combined to enable perception of a large variety of different hues. Furthermore, recent evidence suggests that color analysis and coding cannot be separated from the analysis and coding of other visual attributes such as form and motion. Though there are some brain areas that are more sensitive to color than others, color vision emerges through the combined activity of neurons in many different areas.

  17. Complex adaptation-based LDR image rendering for 3D image reconstruction

    NASA Astrophysics Data System (ADS)

    Lee, Sung-Hak; Kwon, Hyuk-Ju; Sohng, Kyu-Ik

    2014-07-01

    A low-dynamic tone-compression technique is developed for realistic image rendering that can make three-dimensional (3D) images similar to realistic scenes by overcoming brightness dimming in the 3D display mode. The 3D surround provides varying conditions for image quality, illuminant adaptation, contrast, gamma, color, sharpness, and so on. In general, gain/offset adjustment, gamma compensation, and histogram equalization have performed well in contrast compression; however, as a result of signal saturation and clipping effects, image details are removed and information is lost on bright and dark areas. Thus, an enhanced image mapping technique is proposed based on space-varying image compression. The performance of contrast compression is enhanced with complex adaptation in a 3D viewing surround combining global and local adaptation. Evaluating local image rendering in view of tone and color expression, noise reduction, and edge compensation confirms that the proposed 3D image-mapping model can compensate for the loss of image quality in the 3D mode.

  18. Dynamic real-time 4D cardiac MDCT image display using GPU-accelerated volume rendering.

    PubMed

    Zhang, Qi; Eagleson, Roy; Peters, Terry M

    2009-09-01

    Intraoperative cardiac monitoring, accurate preoperative diagnosis, and surgical planning are important components of minimally-invasive cardiac therapy. Retrospective, electrocardiographically (ECG) gated, multidetector computed tomographical (MDCT), four-dimensional (3D + time), real-time, cardiac image visualization is an important tool for the surgeon in such procedure, particularly if the dynamic volumetric image can be registered to, and fused with the actual patient anatomy. The addition of stereoscopic imaging provides a more intuitive environment by adding binocular vision and depth cues to structures within the beating heart. In this paper, we describe the design and implementation of a comprehensive stereoscopic 4D cardiac image visualization and manipulation platform, based on the opacity density radiation model, which exploits the power of modern graphics processing units (GPUs) in the rendering pipeline. In addition, we present a new algorithm to synchronize the phases of the dynamic heart to clinical ECG signals, and to calculate and compensate for latencies in the visualization pipeline. A dynamic multiresolution display is implemented to enable the interactive selection and emphasis of volume of interest (VOI) within the entire contextual cardiac volume and to enhance performance, and a novel color and opacity adjustment algorithm is designed to increase the uniformity of the rendered multiresolution image of heart. Our system provides a visualization environment superior to noninteractive software-based implementations, but with a rendering speed that is comparable to traditional, but inferior quality, volume rendering approaches based on texture mapping. This retrospective ECG-gated dynamic cardiac display system can provide real-time feedback regarding the suspected pathology, function, and structural defects, as well as anatomical information such as chamber volume and morphology.

  19. An efficient low-complexity approach to color trapping

    NASA Astrophysics Data System (ADS)

    Wang, Haiyin; Boutin, Mireille; Trask, Jeffery; Allebach, Jan P.

    2008-01-01

    CMYK color separation is a technique commonly used in printing to reproduce mutli-color images. However, the color planes are generally not perfectly aligned with respect to each other when they are rendered by the imaging stations. This phenomenon, called color plane mis-registration, causes gap and halo artifacts. Trapping algorithms aim to reduce these artifacts by scanning through an image, determining the edges susceptible to mis-registration errors, and moving the edge boundaries of the lighter colorants underneath the edge boundaries of the darker colorants. In this paper, we propose a low-complexity approach to automatic color trapping which hides the effects of small color plane mis-registrations without negatively affecting the overall quality of the printed image.

  20. Effective palette indexing for image compression using self-organization of Kohonen feature map.

    PubMed

    Pei, Soo-Chang; Chuang, Yu-Ting; Chuang, Wei-Hong

    2006-09-01

    The process of limited-color image compression usually involves color quantization followed by palette re-indexing. Palette re-indexing could improve the compression of color-indexed images, but it is still complicated and consumes extra time. Making use of the topology-preserving property of self-organizing Kohonen feature map, we can generate a fairly good color index table to achieve both high image quality and high compression, without re-indexing. Promising experiment results will be presented.

  1. 11. Architect's rendering of the Arcade Building by Furness, Evans ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Architect's rendering of the Arcade Building by Furness, Evans and Co., from Moses King's Philadelphia and Notable Philadelphians, published 1902 for the City's 220th birthday - Arcade Building, Fifteenth & Market Streets, Philadelphia, Philadelphia County, PA

  2. 1. Photocopy of architect's rendering of approved design, which was ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Photocopy of architect's rendering of approved design, which was altered in execution Furness, Evans & Co. 1893 General view - Pennsylvania Railroad Station, Broad Street Station, Broad & Market Streets, Philadelphia, Philadelphia County, PA

  3. Perspective rendering of the competition design for the New Masonic ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Perspective rendering of the competition design for the New Masonic Temple, Philadelphia by architects Fraser, Furness, and Hewitt, 1867 - Masonic Temple, 1 North Broad Street, Philadelphia, Philadelphia County, PA

  4. 12. Historic American Buildings Survey Rendering by C. Howard Crane ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Historic American Buildings Survey Rendering by C. Howard Crane Office, 1919. Courtesy Detroit Historical Society. Photocopy by Jack E. Boucher, 1973 PERSPECTIVE VIEW FROM SOUTH - Orchestra Hall, 3711 Woodward Avenue, Detroit, MI

  5. 38. Photocopy of ink and wash rendering by N. G. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. Photocopy of ink and wash rendering by N. G. Starkwether in collection of Mr. & Mrs. Richard T. Pratt, Camden REAR ELEVATION OF W. C. PRATT'S COUNTRY SEAT - Camden, Rappahannock River, Port Royal, Caroline County, VA

  6. Experiencing "Macbeth": From Text Rendering to Multicultural Performance.

    ERIC Educational Resources Information Center

    Reisin, Gail

    1993-01-01

    Shows how one teacher used innovative methods in teaching William Shakespeare's "Macbeth." Outlines student assignments including text renderings, rewriting a scene from the play, and creating a multicultural scrapbook for the play. (HB)

  7. 37. Photocopy of ink and wash rendering by N. G. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. Photocopy of ink and wash rendering by N. G. Starkwether in collection of Mr. & Mrs. Richard T. Pratt, Camden SIDE ELEVATION OF ITALIAN VILLA FOR W. C. PRATT, ESQr - Camden, Rappahannock River, Port Royal, Caroline County, VA

  8. Studies on the Contamination of Products Produced by Rendering Plants

    PubMed Central

    Tittiger, F.

    1971-01-01

    Studies on the bacterial contamination in rendered product and the environment of five rendering plants were carried out. From a total of 180 samples examined, total bacterial and anaerobic spore counts were conducted on 135. Plants with melter systems produced a sterile product which was recontaminated before reaching the finished stage. Two plants with continuous rendering systems did not achieve sterilization of the product during the heating process. Spore forming organisms regularly survived heating in the continuous rendering system. Salmonellae were isolated from samples collected in four of the five plants under study. Pathogenic Clostridia, especially Cl. novyi, Cl. septicum and Cl. perfringens were present in samples from all plants. Other pathogens found were Staphylococci, Streptococci, Corynebacteria and Pasteurella. PMID:4253467

  9. A Volume Rendering Framework for Visualizing 3D Flow Fields

    NASA Astrophysics Data System (ADS)

    Hsieh, Hsien-Hsi; Li, Liya; Shen, Han-Wei; Tai, Wen-Kai

    In this paper, we present a volume rendering framework for visualizing 3D flow fields. We introduce the concept of coherence field which evaluates the representativeness of a given streamline set for the underlying 3D vector field. Visualization of the coherence field can provide effective visual feedback to the user for incremental insertion of more streamline seeds. Given an initial set of streamlines, a coherence volume is constructed from a distance field to measure the similarity between the existing streamlines and those in their nearby regions based on the difference between the approximate and the actual vector directions. With the visual feedback obtained from rendering the coherence volume, new streamline seeds can be selected by the user or by a heuristic seed selection algorithm to adaptively improve the coherence volume. An improved volume rendering technique that can render user-defined appearance textures is proposed to facilitate macro-visualization of 3D vector fields.

  10. View compensated compression of volume rendered images for remote visualization.

    PubMed

    Lalgudi, Hariharan G; Marcellin, Michael W; Bilgin, Ali; Oh, Han; Nadar, Mariappan S

    2009-07-01

    Remote visualization of volumetric images has gained importance over the past few years in medical and industrial applications. Volume visualization is a computationally intensive process, often requiring hardware acceleration to achieve a real time viewing experience. One remote visualization model that can accomplish this would transmit rendered images from a server, based on viewpoint requests from a client. For constrained server-client bandwidth, an efficient compression scheme is vital for transmitting high quality rendered images. In this paper, we present a new view compensation scheme that utilizes the geometric relationship between viewpoints to exploit the correlation between successive rendered images. The proposed method obviates motion estimation between rendered images, enabling significant reduction to the complexity of a compressor. Additionally, the view compensation scheme, in conjunction with JPEG2000 performs better than AVC, the state of the art video compression standard.

  11. Boundary emphasis transfer function generation based on HSL color space

    NASA Astrophysics Data System (ADS)

    Li, Xiao; Wu, Jianhuang; Luo, Shengzhou; Ma, Xin

    2011-10-01

    Direct volume rendering has been received much attention since it need not to extract geometric primitives for visualization and its performance is generally better than surface rendering. Transfer functions, which are used for mapping scalar field to optical properties, are of vital importance in obtaining a sensible rendering result from volume data. Though traditional color transfer functions are in RGB color space, HSL color space that conveys semantic meanings is more intuitive and user-friendly. In this paper, we present a novel approach aims to emphasize and distinguish strong boundaries between different materials. We achieve it by using data value, gradient magnitude and dimension of the volumetric data to set opacity. Then, through a linear map from data value, gradient magnitude and second derivative to hue, saturation and lightness respectively, a color transfer function is obtained in HSL color space. Experimental tests on real-world datasets indicate that our method could achieve desirable rendering results with revealing important boundaries between different structures and indicating data value's distribution in the volume by using different colors.

  12. 30. Photocopy of photograph of architectural rendering by office of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. Photocopy of photograph of architectural rendering by office of Clarence H. Johnston, Sr., dated 1929; photograph in Clarence H. Johnston Papers, Northwest Architectural Archives, University of Minnesota; photographer unknown; location of rendering unknown; delineator unknown; THREE-QUARTER VIEW SHOWING WEST SIDE AND SOUTH FRONT; LOOKING NORTHEAST - Northwest Airways Hangar & Administration Building, 590 Bayfield Street, St. Paul Downtown Airport (Holman), Saint Paul, Ramsey County, MN

  13. [The development of the American carcass rendering industry (author's transl)].

    PubMed

    Cox, J S

    1980-03-01

    The American rendering organization is different from that in Europe, it has historycally developed as an industry separate from slaughter houses, it has grown and waxed very profitable on a world wide basis, and finally it is now under technological attack which may eventually fundamentally change it and make it more like the organization of rendering that you have in much of Europe after all.

  14. Color accuracy and reproducibility in whole slide imaging scanners

    NASA Astrophysics Data System (ADS)

    Shrestha, Prarthana; Hulsken, Bas

    2014-03-01

    In this paper, we propose a work-flow for color reproduction in whole slide imaging (WSI) scanners such that the colors in the scanned images match to the actual slide color and the inter scanner variation is minimum. We describe a novel method of preparation and verification of the color phantom slide, consisting of a standard IT8- target transmissive film, which is used in color calibrating and profiling the WSI scanner. We explore several ICC compliant techniques in color calibration/profiling and rendering intents for translating the scanner specific colors to the standard display (sRGB) color-space. Based on the quality of color reproduction in histopathology tissue slides, we propose the matrix-based calibration/profiling and absolute colorimetric rendering approach. The main advantage of the proposed work-ow is that it is compliant to the ICC standard, applicable to color management systems in different platforms, and involves no external color measurement devices. We measure objective color performance using CIE-DeltaE2000 metric, where DeltaE values below 1 is considered imperceptible. Our evaluation 14 phantom slides, manufactured according to the proposed method, show an average inter-slide color difference below 1 DeltaE. The proposed work-flow is implemented and evaluated in 35 Philips Ultra Fast Scanners (UFS). The results show that the average color difference between a scanner and the reference is 3.5 DeltaE, and among the scanners is 3.1 DeltaE. The improvement on color performance upon using the proposed method is apparent on the visual color quality of the tissues scans.

  15. Color superconductivity

    SciTech Connect

    Wilczek, F.

    1997-09-22

    The asymptotic freedom of QCD suggests that at high density - where one forms a Fermi surface at very high momenta - weak coupling methods apply. These methods suggest that chiral symmetry is restored and that an instability toward color triplet condensation (color superconductivity) sets in. Here I attempt, using variational methods, to estimate these effects more precisely. Highlights include demonstration of a negative pressure in the uniform density chiral broken phase for any non-zero condensation, which we take as evidence for the philosophy of the MIT bag model; and demonstration that the color gap is substantial - several tens of MeV - even at modest densities. Since the superconductivity is in a pseudoscalar channel, parity is spontaneously broken.

  16. High-fidelity real-time maritime scene rendering

    NASA Astrophysics Data System (ADS)

    Shyu, Hawjye; Taczak, Thomas M.; Cox, Kevin; Gover, Robert; Maraviglia, Carlos; Cahill, Colin

    2011-06-01

    The ability to simulate authentic engagements using real-world hardware is an increasingly important tool. For rendering maritime environments, scene generators must be capable of rendering radiometrically accurate scenes with correct temporal and spatial characteristics. When the simulation is used as input to real-world hardware or human observers, the scene generator must operate in real-time. This paper introduces a novel, real-time scene generation capability for rendering radiometrically accurate scenes of backgrounds and targets in maritime environments. The new model is an optimized and parallelized version of the US Navy CRUISE_Missiles rendering engine. It was designed to accept environmental descriptions and engagement geometry data from external sources, render a scene, transform the radiometric scene using the electro-optical response functions of a sensor under test, and output the resulting signal to real-world hardware. This paper reviews components of the scene rendering algorithm, and details the modifications required to run this code in real-time. A description of the simulation architecture and interfaces to external hardware and models is presented. Performance assessments of the frame rate and radiometric accuracy of the new code are summarized. This work was completed in FY10 under Office of Secretary of Defense (OSD) Central Test and Evaluation Investment Program (CTEIP) funding and will undergo a validation process in FY11.

  17. Remote volume rendering pipeline for mHealth applications

    NASA Astrophysics Data System (ADS)

    Gutenko, Ievgeniia; Petkov, Kaloian; Papadopoulos, Charilaos; Zhao, Xin; Park, Ji Hwan; Kaufman, Arie; Cha, Ronald

    2014-03-01

    We introduce a novel remote volume rendering pipeline for medical visualization targeted for mHealth (mobile health) applications. The necessity of such a pipeline stems from the large size of the medical imaging data produced by current CT and MRI scanners with respect to the complexity of the volumetric rendering algorithms. For example, the resolution of typical CT Angiography (CTA) data easily reaches 512^3 voxels and can exceed 6 gigabytes in size by spanning over the time domain while capturing a beating heart. This explosion in data size makes data transfers to mobile devices challenging, and even when the transfer problem is resolved the rendering performance of the device still remains a bottleneck. To deal with this issue, we propose a thin-client architecture, where the entirety of the data resides on a remote server where the image is rendered and then streamed to the client mobile device. We utilize the display and interaction capabilities of the mobile device, while performing interactive volume rendering on a server capable of handling large datasets. Specifically, upon user interaction the volume is rendered on the server and encoded into an H.264 video stream. H.264 is ubiquitously hardware accelerated, resulting in faster compression and lower power requirements. The choice of low-latency CPU- and GPU-based encoders is particularly important in enabling the interactive nature of our system. We demonstrate a prototype of our framework using various medical datasets on commodity tablet devices.

  18. Parallel Rendering of Large Time-Varying Volume Data

    NASA Technical Reports Server (NTRS)

    Garbutt, Alexander E.

    2005-01-01

    Interactive visualization of large time-varying 3D volume datasets has been and still is a great challenge to the modem computational world. It stretches the limits of the memory capacity, the disk space, the network bandwidth and the CPU speed of a conventional computer. In this SURF project, we propose to develop a parallel volume rendering program on SGI's Prism, a cluster computer equipped with state-of-the-art graphic hardware. The proposed program combines both parallel computing and hardware rendering in order to achieve an interactive rendering rate. We use 3D texture mapping and a hardware shader to implement 3D volume rendering on each workstation. We use SGI's VisServer to enable remote rendering using Prism's graphic hardware. And last, we will integrate this new program with ParVox, a parallel distributed visualization system developed at JPL. At the end of the project, we Will demonstrate remote interactive visualization using this new hardware volume renderer on JPL's Prism System using a time-varying dataset from selected JPL applications.

  19. Color Sense

    ERIC Educational Resources Information Center

    Johnson, Heidi S. S.; Maki, Jennifer A.

    2009-01-01

    This article reports a study conducted by members of the WellU Academic Integration Subcommittee of The College of St. Scholastica's College's Healthy Campus Initiative plan whose purpose was to determine whether changing color in the classroom could have a measurable effect on students. One simple improvement a school can make in a classroom is…

  20. Object knowledge changes visual appearance: semantic effects on color afterimages.

    PubMed

    Lupyan, Gary

    2015-10-01

    According to predictive coding models of perception, what we see is determined jointly by the current input and the priors established by previous experience, expectations, and other contextual factors. The same input can thus be perceived differently depending on the priors that are brought to bear during viewing. Here, I show that expected (diagnostic) colors are perceived more vividly than arbitrary or unexpected colors, particularly when color input is unreliable. Participants were tested on a version of the 'Spanish Castle Illusion' in which viewing a hue-inverted image renders a subsequently shown achromatic version of the image in vivid color. Adapting to objects with intrinsic colors (e.g., a pumpkin) led to stronger afterimages than adapting to arbitrarily colored objects (e.g., a pumpkin-colored car). Considerably stronger afterimages were also produced by scenes containing intrinsically colored elements (grass, sky) compared to scenes with arbitrarily colored objects (books). The differences between images with diagnostic and arbitrary colors disappeared when the association between the image and color priors was weakened by, e.g., presenting the image upside-down, consistent with the prediction that color appearance is being modulated by color knowledge. Visual inputs that conflict with prior knowledge appear to be phenomenologically discounted, but this discounting is moderated by input certainty, as shown by the final study which uses conventional images rather than afterimages. As input certainty is increased, unexpected colors can become easier to detect than expected ones, a result consistent with predictive-coding models. PMID:26386775

  1. GPU-based high-precision real-time radiometric rendering for IR scene generation

    NASA Astrophysics Data System (ADS)

    Huang, Xi; Zhang, Jianqi; Zhang, Shaoze; Wu, Xin

    2014-07-01

    Aiming at the problem that traditional infrared scene real-time radiometric rendering method leads to greater calculation error for securing real-time purpose, this article studies the IR rendering comprehensive optimization method, which secures real-time performance as well as calculation accuracy. Firstly, based on the effective average value principle, the spectrum coupling thermal emission and reflected radiations in the spectral radiometric equation are decomposed into physical quantities, and the spectral radiometric equation is improved to become a simpler calculation between "primer" radiance terms and effective average factors. Secondly, the parameter processing method is proposed to cope with the situation when index parameters of effective average factors exceed the maximum dimensionalities of graphics processing unit (GPU) look-up-table (LUT); and pre-calculation method is applied to promote the real-time evaluation efficiency of the physical quantities in the radiometric equation. Finally, concurrent computation of radiometric equation is achieved with GPU IR scene generation software and the precise and real-time rendering of three-dimensional IR scene is realized.

  2. Kernel based color estimation for night vision imagery

    NASA Astrophysics Data System (ADS)

    Gu, Xiaojing; Sun, Shaoyuan; Fang, Jian'an; Zhou, Peng

    2012-04-01

    Displaying night vision (NV) imagery with colors can largely improve observer's performance of scene recognition and situational awareness comparing to the conventional monochrome representation. However, estimating colors for single-band NV imagery has two challenges: deriving an appropriate color mapping model and extracting sufficient image features required by the model. To address these, a kernel based regression model and a set of multi-scale image features are used here. The proposed method can automatically render single-band NV imagery with natural colors, even when it has abnormal luminance distribution and lacks identifiable details.

  3. Color constancy - A method for recovering surface spectral reflectance

    NASA Technical Reports Server (NTRS)

    Maloney, L. T.; Wandell, B. A.

    1986-01-01

    An algorithm has been developed for estimating the surface reflectance functions of objects in a scene with incomplete knowledge of the spectral power distribution of the ambient light. An image processing system employing this algorithm can assign colors that are constant despite changes in the lighting of the scene; this capability is essential to correct color rendering in photography, TV, and in the construction of artificial visual systems for robotics. Attention is given to the way in which constraints on lights and surfaces in the environment make color-constancy possible for a visual system, and the algorithm's implications for human color vision are discussed.

  4. Adaptive image contrast enhancement algorithm for point-based rendering

    NASA Astrophysics Data System (ADS)

    Xu, Shaoping; Liu, Xiaoping P.

    2015-03-01

    Surgical simulation is a major application in computer graphics and virtual reality, and most of the existing work indicates that interactive real-time cutting simulation of soft tissue is a fundamental but challenging research problem in virtual surgery simulation systems. More specifically, it is difficult to achieve a fast enough graphic update rate (at least 30 Hz) on commodity PC hardware by utilizing traditional triangle-based rendering algorithms. In recent years, point-based rendering (PBR) has been shown to offer the potential to outperform the traditional triangle-based rendering in speed when it is applied to highly complex soft tissue cutting models. Nevertheless, the PBR algorithms are still limited in visual quality due to inherent contrast distortion. We propose an adaptive image contrast enhancement algorithm as a postprocessing module for PBR, providing high visual rendering quality as well as acceptable rendering efficiency. Our approach is based on a perceptible image quality technique with automatic parameter selection, resulting in a visual quality comparable to existing conventional PBR algorithms. Experimental results show that our adaptive image contrast enhancement algorithm produces encouraging results both visually and numerically compared to representative algorithms, and experiments conducted on the latest hardware demonstrate that the proposed PBR framework with the postprocessing module is superior to the conventional PBR algorithm and that the proposed contrast enhancement algorithm can be utilized in (or compatible with) various variants of the conventional PBR algorithm.

  5. Color considerations in fluorescent solar concentrator stacks

    NASA Astrophysics Data System (ADS)

    Swift, Paul D.; Smith, Geoff B.

    2003-09-01

    We present modeled results of the luminous and color outputs of a three-layer stack of fluorescent planar concentrators (FPCs). FPCs have the potential to provide sufficient luminous output to illuminate moderate-sized rooms for reasonably-sized collecting areas. It is of course necessary not only that the lumens be sufficient, but also that the light be sufficiently white as to be comfortable. Modeling shows that by use of a stack of three FPCs, one each of violet, green, and red, it is possible to achieve good color rendering and sufficient lighting levels for room illumination.

  6. Colorizing metals with femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Vorobyev, A. Y.; Guo, Chunlei

    2008-01-01

    For centuries, it had been the dream of alchemists to turn inexpensive metals into gold. Certainly, it is not enough from an alchemist's point of view to transfer only the appearance of a metal to gold. However, the possibility of rendering a certain metal to a completely different color without coating can be very interesting in its own right. In this work, we demonstrate a femtosecond laser processing technique that allows us to create a variety of colors on a metal that ultimately leads us to control its optical properties from UV to terahertz.

  7. Colorizing metals with femtosecond laser pulses

    SciTech Connect

    Vorobyev, A. Y.; Guo Chunlei

    2008-01-28

    For centuries, it had been the dream of alchemists to turn inexpensive metals into gold. Certainly, it is not enough from an alchemist's point of view to transfer only the appearance of a metal to gold. However, the possibility of rendering a certain metal to a completely different color without coating can be very interesting in its own right. In this work, we demonstrate a femtosecond laser processing technique that allows us to create a variety of colors on a metal that ultimately leads us to control its optical properties from UV to terahertz.

  8. Color structured light imaging of skin

    NASA Astrophysics Data System (ADS)

    Yang, Bin; Lesicko, John; Moy, Austin; Reichenberg, Jason; Sacks, Michael; Tunnell, James W.

    2016-05-01

    We illustrate wide-field imaging of skin using a structured light (SL) approach that highlights the contrast from superficial tissue scattering. Setting the spatial frequency of the SL in a regime that limits the penetration depth effectively gates the image for photons that originate from the skin surface. Further, rendering the SL images in a color format provides an intuitive format for viewing skin pathologies. We demonstrate this approach in skin pathologies using a custom-built handheld SL imaging system.

  9. Indexing Images.

    ERIC Educational Resources Information Center

    Rasmussen, Edie M.

    1997-01-01

    Focuses on access to digital image collections by means of manual and automatic indexing. Contains six sections: (1) Studies of Image Systems and their Use; (2) Approaches to Indexing Images; (3) Image Attributes; (4) Concept-Based Indexing; (5) Content-Based Indexing; and (6) Browsing in Image Retrieval. Contains 105 references. (AEF)

  10. Structural color from colloidal glasses

    NASA Astrophysics Data System (ADS)

    Magkiriadou, Sofia

    When a material has inhomogeneities at a lengthscale comparable to the wavelength of light, interference can give rise to structural colors: colors that originate from the interaction of the material's microstructure with light and do not require absorbing dyes. In this thesis we study a class of these materials, called photonic glasses, where the inhomogeneities form a dense and random arrangement. Photonic glasses have angle-independent structural colors that look like those of conventional dyes. However, when this work started, there was only a handful of colors accessible with photonic glasses, mostly hues of blue. We use various types of colloidal particles to make photonic glasses, and we study, both theoretically and experimentally, how the optical properties of these glasses relate to their structure and constituent particles. Based on our observations from glasses of conventional particles, we construct a theoretical model that explains the scarcity of yellow, orange, and red photonic glasses. Guided by this model, we develop novel colloidal systems that allow a higher degree of control over structural color. We assemble glasses of soft, core-shell particles with scattering cores and transparent shells, where the resonant wavelength can be tuned independently of the reflectivity. We then encapsulate glasses of these core-shell particles into emulsion droplets of tunable size; in this system, we observe, for the first time, angle-independent structural colors that cover the entire visible spectrum. To enhance color saturation, we begin experimenting with inverse glasses, where the refractive index of the particles is lower than the refractive index of the medium, with promising results. Finally, based on our theoretical model for scattering from colloidal glasses, we begin an exploration of the color gamut that could be achieved with this technique, and we find that photonic glasses are a promising approach to a new type of long-lasting, non-toxic, and

  11. Parallel volume rendering on the IBM Blue Gene/P.

    SciTech Connect

    Peterka, T.; Yu, H.; Ross, R.; Ma, K.-L.; Mathematics and Computer Science; Univ. of California at Davis

    2008-01-01

    Parallel ray casting volume rendering is implemented and tested on an IBM Blue Gene distributed memory parallel architecture. Data are presented from experiments under a number of different conditions, including dataset size, number of processors, low and high quality rendering, offline storage of results, and streaming of images for remote display. Performance is divided into three main sections of the algorithm: disk I/O, rendering, and compositing. The dynamic balance between these tasks varies with the number of processors and other conditions. Lessons learned from the work include understanding the balance between parallel I/O, computation, and communication within the context of visualization on supercomputers, recommendations for tuning and optimization, and opportunities for scaling further in the future. Extrapolating these results to very large data and image sizes suggests that a distributed memory HPC architecture such as the Blue Gene is a viable platform for some types of visualization at very large scales.

  12. Algorithms for Haptic Rendering of 3D Objects

    NASA Technical Reports Server (NTRS)

    Basdogan, Cagatay; Ho, Chih-Hao; Srinavasan, Mandayam

    2003-01-01

    Algorithms have been developed to provide haptic rendering of three-dimensional (3D) objects in virtual (that is, computationally simulated) environments. The goal of haptic rendering is to generate tactual displays of the shapes, hardnesses, surface textures, and frictional properties of 3D objects in real time. Haptic rendering is a major element of the emerging field of computer haptics, which invites comparison with computer graphics. We have already seen various applications of computer haptics in the areas of medicine (surgical simulation, telemedicine, haptic user interfaces for blind people, and rehabilitation of patients with neurological disorders), entertainment (3D painting, character animation, morphing, and sculpting), mechanical design (path planning and assembly sequencing), and scientific visualization (geophysical data analysis and molecular manipulation).

  13. Chromium Renderserver: Scalable and Open Source Remote RenderingInfrastructure

    SciTech Connect

    Paul, Brian; Ahern, Sean; Bethel, E. Wes; Brugger, Eric; Cook,Rich; Daniel, Jamison; Lewis, Ken; Owen, Jens; Southard, Dale

    2007-12-01

    Chromium Renderserver (CRRS) is software infrastructure thatprovides the ability for one or more users to run and view image outputfrom unmodified, interactive OpenGL and X11 applications on a remote,parallel computational platform equipped with graphics hardwareaccelerators via industry-standard Layer 7 network protocolsand clientviewers. The new contributions of this work include a solution to theproblem of synchronizing X11 and OpenGL command streams, remote deliveryof parallel hardware-accelerated rendering, and a performance analysis ofseveral different optimizations that are generally applicable to avariety of rendering architectures. CRRSis fully operational, Open Sourcesoftware.

  14. Introduction To Color Vision

    NASA Astrophysics Data System (ADS)

    Thorell, Lisa G.

    1983-08-01

    Several human cognitive studies have reported that color facilitates certain learning, memory and search tasks. Consideration of the color-opponent organization of human color vision and the spatial modulation transfer function for color suggests several simple sensory explanations.

  15. Cross-Modal Associations between Color and Haptics.

    PubMed

    Slobodenyuk, Nadiya; Jraissati, Yasmina; Kanso, Ali; Ghanem, Lama; Elhajj, Imad

    2015-05-01

    The objective of the present study was to explore cross-modal associations between color and tactile sensation while using haptically rendered virtual stimuli with substance properties of roughness/smoothness, hardness/softness, heaviness/lightness, elasticity/inelasticity, and adhesiveness/nonadhesiveness. The stimuli with the indicated properties were rendered with the aid of SensAble PHANTOM OMNI® haptic device. The experimental setup required the participants to use exploratory procedures typical to real object interaction, and select a color from the HSV color space that matched the experienced sensation. The findings of our investigation reveal systematic mapping between color characteristics and intensity of the haptic stimuli. Qualitatively different haptic sensations, however, produced relatively similar patterns of cross-modal associations.

  16. Stereo vision-based depth of field rendering on a mobile device

    NASA Astrophysics Data System (ADS)

    Wang, Qiaosong; Yu, Zhan; Rasmussen, Christopher; Yu, Jingyi

    2014-03-01

    The depth of field (DoF) effect is a useful tool in photography and cinematography because of its aesthetic value. However, capturing and displaying dynamic DoF effect were until recently a quality unique to expensive and bulky movie cameras. A computational approach to generate realistic DoF effects for mobile devices such as tablets is proposed. We first calibrate the rear-facing stereo cameras and rectify the stereo image pairs through FCam API, then generate a low-res disparity map using graph cuts stereo matching and subsequently upsample it via joint bilateral upsampling. Next, we generate a synthetic light field by warping the raw color image to nearby viewpoints, according to the corresponding values in the upsampled high-resolution disparity map. Finally, we render dynamic DoF effect on the tablet screen with light field rendering. The user can easily capture and generate desired DoF effects with arbitrary aperture sizes or focal depths using the tablet only, with no additional hardware or software required. The system has been examined in a variety of environments with satisfactory results, according to the subjective evaluation tests.

  17. Stereoscopic imaging: filling disoccluded areas in depth image-based rendering

    NASA Astrophysics Data System (ADS)

    Vázquez, Carlos; Tam, Wa James; Speranza, Filippo

    2006-10-01

    Depth image based rendering (DIBR) is a method for converting 2D material to stereoscopic 3D. With DIBR, information contained in a gray-level (luminance intensity) depth map is used to shift pixels in the 2D image to generate a new image as if it were captured from a new viewpoint. The larger the shift (binocular parallax), the larger is the perceived depth of the generated stereoscopic pair. However, a major problem with DIBR is that the shifted pixels now occupy new positions and leave areas that they originally occupied "empty." These disoccluded regions have to be filled properly, otherwise they can degrade image quality. In this study we investigated different methods for filling these disoccluded regions: (a) Filling regions with a constant color, (b) filling regions with horizontal linear interpolation of values on the hole border, (c) solving the Laplace equation on the hole boundary and propagate the values inside the region, (d) horizontal extrapolation with depth information taken into account, (e) variational inpainting with depth information taken into account, and (f) preprocessing of the depth map to prevent disoccluded regions from appearing. The methods differed in the time required for computing and filling, and the appearance of the filled-in regions. We assessed the subjective image quality outcome for several stereoscopic test images in which the left-eye view was the source and the right-eye view was a rendered view, in line with suggestions in the literature for the asymmetrical coding of stereoscopic images.

  18. Inconspicuous structural coloration in the elytra of beetles Chlorophila obscuripennis (Coleoptera)

    NASA Astrophysics Data System (ADS)

    Liu, Feng; Yin, Haiwei; Dong, Biqin; Qing, Youhua; Zhao, Li; Meyer, Serge; Liu, Xiaohan; Zi, Jian; Chen, Bin

    2008-01-01

    The elytra of male beetles Chlorophila obscuripennis (Coleoptera) display an inconspicuous iridescent bluish green color. By structural characterizations we find that the outermost elytral surface comprises a sculpted multilayer, which is the origin of structural coloration. In elytra both structural green and cyan colors are observed which arise from the modulations imposed on the multilayer, leading to a bluish green color by color mixing. The adoption of the sculpted multilayer can render structural coloration inconspicuous, which could be advantageous for camouflage. In addition, it can cause light emergence at nonspecular angles.

  19. Photographic copy of photograph of the Architect's rendering of the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photographic copy of photograph of the Architect's rendering of the proposed Auditorium Building (1904-05) (original photograph in possession of Brunner and Brunner, Architect and Engineers, Inc., St. Joseph, Missouri) VIEW OF SOUTHEAST CORNER - Old City Auditorium, 404-424 North Fourth Street, Saint Joseph, Buchanan County, MO

  20. 11. Historic photo of cutaway rendering of rocket engine test ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Historic photo of cutaway rendering of rocket engine test facility complex, June 11, 1965. On file at NASA Plumbrook Research Center, Sandusky, Ohio. NASA GRC photo number C-74433. - Rocket Engine Testing Facility, NASA Glenn Research Center, Cleveland, Cuyahoga County, OH

  1. 10. Historic photo of rendering of rocket engine test facility ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Historic photo of rendering of rocket engine test facility complex, April 28, 1964. On file at NASA Plumbrook Research Center, Sandusky, Ohio. NASA GRC photo number C-69472. - Rocket Engine Testing Facility, NASA Glenn Research Center, Cleveland, Cuyahoga County, OH

  2. 7 CFR 54.1016 - Advance information concerning service rendered.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Advance information concerning service rendered. 54..., Processing, and Packaging of Livestock and Poultry Products § 54.1016 Advance information concerning service... MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE...

  3. 7 CFR 53.17 - Advance information concerning service rendered.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Advance information concerning service rendered. 53.17... (CONTINUED) LIVESTOCK (GRADING, CERTIFICATION, AND STANDARDS) Regulations Service § 53.17 Advance information... SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED)...

  4. A versatile optical model for hybrid rendering of volume data.

    PubMed

    Yang, Fei; Li, Qingde; Xiang, Dehui; Cao, Yong; Tian, Jie

    2012-06-01

    In volume rendering, most optical models currently in use are based on the assumptions that a volumetric object is a collection of particles and that the macro behavior of particles, when they interact with light rays, can be predicted based on the behavior of each individual particle. However, such models are not capable of characterizing the collective optical effect of a collection of particles which dominates the appearance of the boundaries of dense objects. In this paper, we propose a generalized optical model that combines particle elements and surface elements together to characterize both the behavior of individual particles and the collective effect of particles. The framework based on a new model provides a more powerful and flexible tool for hybrid rendering of isosurfaces and transparent clouds of particles in a single scene. It also provides a more rational basis for shading, so the problem of normal-based shading in homogeneous regions encountered in conventional volume rendering can be easily avoided. The model can be seen as an extension to the classical model. It can be implemented easily, and most of the advanced numerical estimation methods previously developed specifically for the particle-based optical model, such as preintegration, can be applied to the new model to achieve high-quality rendering results.

  5. 35. Photocopy of detail of ink and wash rendering by ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    35. Photocopy of detail of ink and wash rendering by N. G. Starkwether in collection of Mr. & Mrs. Richard T. Pratt, Camden ELEVATIONS OF ITALIAN VILLA FOR WILLIAM C. PRATT - CAMDEN PLACE - RIVER FRONT - Camden, Rappahannock River, Port Royal, Caroline County, VA

  6. 36. Photocopy of detail of ink and wash rendering by ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. Photocopy of detail of ink and wash rendering by N. G. Starkwether in collection of Mr. & Mrs. Richard T. Pratt, Camden ELEVATIONS OF ITALIAN VILLA FOR WILLIAM C. PRATT - CAMDEN PLACE - DRIVE FRONT - Camden, Rappahannock River, Port Royal, Caroline County, VA

  7. 17 CFR 256.457 - Services rendered to associate companies.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Services rendered to associate companies. 256.457 Section 256.457 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION... cost. See accounts 457-1 through 457-3. Overbillings or underbillings arising from adjustments...

  8. 103. Photocopy of architect's rendering from Renwick's office, signed lower ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    103. Photocopy of architect's rendering from Renwick's office, signed lower right 'H. C. Moore Draughtsman May 1848' & signed lower left 'Louis R. Townsend pinxt. June 1848' NORTH FRONT, SMITHSONIAN INSTITUTION. - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  9. Imaging of Temporomandibular Joint: Approach by Direct Volume Rendering

    PubMed Central

    Caradonna, Carola; Bruschetta, Daniele; Vaccarino, Gianluigi; Milardi, Demetrio

    2014-01-01

    Background: The purpose of this study was to conduct a morphological analysis of the temporomandibular joint, a highly specialized synovial joint that permits movement and function of the mandible. Materials and Methods: We have studied the temporom-andibular joint anatomy, directly on the living, from 3D images obtained by medical imaging Computed Tomography and Nuclear Magnetic Resonance acquisition, and subsequent re-engineering techniques 3D Surface Rendering and Volume Rendering. Data were analysed with the goal of being able to isolate, identify and distinguish the anatomical structures of the joint, and get the largest possible number of information utilizing software for post-processing work. Results: It was possible to reproduce anatomy of the skeletal structures, as well as through acquisitions of Magnetic Resonance Imaging; it was also possible to visualize the vascular, muscular, ligamentous and tendinous components of the articular complex, and also the capsule and the fibrous cartilaginous disc. We managed the Surface Rendering and Volume Rendering, not only to obtain three-dimensional images for colour and for resolution comparable to the usual anatomical preparations, but also a considerable number of anatomical, minuter details, zooming, rotating and cutting the same images with linking, graduating the colour, transparency and opacity from time to time. Conclusion: These results are encouraging to stimulate further studies in other anatomical districts. PMID:25664280

  10. Hidden Color

    NASA Astrophysics Data System (ADS)

    Ji, C.-R.

    2014-10-01

    With the acceptance of QCD as the fundamental theory of strong interactions, one of the basic problems in the analysis of nuclear phenomena became how to consistently account for the effects of the underlying quark/gluon structure of nucleons and nuclei. Besides providing more detailed understanding of conventional nuclear physics, QCD may also point to novel phenomena accessible by new or upgraded nuclear experimental facilities. We discuss a few interesting applications of QCD to nuclear physics with an emphasis on the hidden color degrees of freedom.

  11. Broadband full-color monolithic InGaN light-emitting diodes by self-assembled InGaN quantum dots

    NASA Astrophysics Data System (ADS)

    Li, Hongjian; Li, Panpan; Kang, Junjie; Ding, Jiianfeng; Ma, Jun; Zhang, Yiyun; Yi, Xiaoyan; Wang, Guohong

    2016-10-01

    We have presented broadband full-color monolithic InGaN light-emitting diodes (LEDs) by self-assembled InGaN quantum dots (QDs) using metal organic chemical vapor deposition (MOCVD). The electroluminescence spectra of the InGaN QDs LEDs are extremely broad span from 410 nm to 720 nm with a line-width of 164 nm, covering entire visible wavelength range. A color temperature of 3370 K and a color rendering index of 69.3 have been achieved. Temperature-dependent photoluminescence measurements reveal a strong carriers localization effect of the InGaN QDs layer by obvious blue-shift of emission peak from 50 K to 300 K. The broadband luminescence spectrum is believed to be attributed to the injected carriers captured by the different localized states of InGaN QDs with various sizes, shapes and indium compositions, leading to a full visible color emission. The successful realization of our broadband InGaN QDs LEDs provide a convenient and practical method for the fabrication of GaN-based monolithic full-color LEDs in wafer scale.

  12. Broadband full-color monolithic InGaN light-emitting diodes by self-assembled InGaN quantum dots

    PubMed Central

    Li, Hongjian; Li, Panpan; Kang, Junjie; Ding, Jiianfeng; Ma, Jun; Zhang, Yiyun; Yi, Xiaoyan; Wang, Guohong

    2016-01-01

    We have presented broadband full-color monolithic InGaN light-emitting diodes (LEDs) by self-assembled InGaN quantum dots (QDs) using metal organic chemical vapor deposition (MOCVD). The electroluminescence spectra of the InGaN QDs LEDs are extremely broad span from 410 nm to 720 nm with a line-width of 164 nm, covering entire visible wavelength range. A color temperature of 3370 K and a color rendering index of 69.3 have been achieved. Temperature-dependent photoluminescence measurements reveal a strong carriers localization effect of the InGaN QDs layer by obvious blue-shift of emission peak from 50 K to 300 K. The broadband luminescence spectrum is believed to be attributed to the injected carriers captured by the different localized states of InGaN QDs with various sizes, shapes and indium compositions, leading to a full visible color emission. The successful realization of our broadband InGaN QDs LEDs provide a convenient and practical method for the fabrication of GaN-based monolithic full-color LEDs in wafer scale. PMID:27734917

  13. Do focal colors look particularly "colorful"?

    PubMed

    Witzel, Christoph; Franklin, Anna

    2014-04-01

    If the most typical red, yellow, green, and blue were particularly colorful (i.e., saturated), they would "jump out to the eye." This would explain why even fundamentally different languages have distinct color terms for these focal colors, and why unique hues play a prominent role in subjective color appearance. In this study, the subjective saturation of 10 colors around each of these focal colors was measured through a pairwise matching task. Results show that subjective saturation changes systematically across hues in a way that is strongly correlated to the visual gamut, and exponentially related to sensitivity but not to focal colors.

  14. Cognitive aspects of color

    NASA Astrophysics Data System (ADS)

    Derefeldt, Gunilla A. M.; Menu, Jean-Pierre; Swartling, Tiina

    1995-04-01

    This report surveys cognitive aspects of color in terms of behavioral, neuropsychological, and neurophysiological data. Color is usually defined as psychophysical color or as perceived color. Behavioral data on categorical color perception, absolute judgement of colors, color coding, visual search, and visual awareness refer to the more cognitive aspects of color. These are of major importance in visual synthesis and spatial organization, as already shown by the Gestalt psychologists. Neuropsychological and neurophysiological findings provide evidence for an interrelation between cognitive color and spatial organization. Color also enhances planning strategies, as has been shown by studies on color and eye movements. Memory colors and the color- language connections in the brain also belong among the cognitive aspects of color.

  15. Qualitative and quantitative comparisons of multispectral night vision colorization techniques

    NASA Astrophysics Data System (ADS)

    Zheng, Yufeng; Dong, Wenjie; Blasch, Erik P.

    2012-08-01

    Multispectral images enable robust night vision (NV) object assessment over day-night conditions. Furthermore, colorized multispectral NV images can enhance human vision by improving observer object classification and reaction times, especially for low light conditions. NV colorization techniques can produce the colorized images that closely resemble natural scenes. Qualitative (subjective) and quantitative (objective) comparisons of NV colorization techniques proposed in the past decade are made and two categories of coloring methods, color fusion and color mapping, are discussed and compared. Color fusion directly combines multispectral NV images into a color-version image by mixing pixel intensities at different color planes, of which a channel-based color fusion method is reviewed. Color-mapping usually maps the color properties of a false-colored NV image (source) onto that of a true-color daylight target picture (reference). Four coloring-mapping methods-statistical matching, histogram matching, joint histogram matching, and look-up table (LUT)-are presented and compared, including a new color-mapping method called joint-histogram matching (JHM). The experimental NV imagery includes visible (Red-Green-Blue), image-intensified, near infrared, and long-wave infrared images. The qualitative evaluations are conducted by visual inspections of the colorized images, whereas the quantitative evaluations are achieved by a newly proposed metric, objective evaluation index. From the experimental results according to both qualitative and quantitative evaluations, the following conclusions can be drawn: the segmentation-based colorization method produces very impressive and realistic colors but requires intense computations; color fusion and LUT-based methods run very fast but with less realistic results; the statistic-matching method always provides acceptable results; histogram matching and joint-histogram matching can generate impressive and vivid colors when the color

  16. 'Payson' Panorama in False Color

    NASA Technical Reports Server (NTRS)

    2006-01-01

    The panoramic camera aboard NASA's Mars Exploration Rover Opportunity acquired this panorama of the 'Payson' outcrop on the western edge of 'Erebus' Crater during Opportunity's sol 744 (Feb. 26, 2006). From this vicinity at the northern end of the outcrop, layered rocks are observed in the crater wall, which is about 1 meter (3.3 feet) thick. The view also shows rocks disrupted by the crater-forming impact event and subjected to erosion over time.

    To the left of the outcrop, a flat, thin layer of spherule-rich soils overlies more outcrop materials. The rover is currently traveling down this 'road' and observing the approximately 25-meter (82-foot) length of the outcrop prior to departing Erebus crater.

    The panorama camera took 28 separate exposures of this scene, using four different filters. The resulting panorama covers about 90 degrees of terrain around the rover. This false-color rendering was made using the camera's 753-nanometer, 535-nanometer and 423-nanometer filters. Using false color enhances the subtle color differences between layers of rocks and soils in the scene so that scientists can better analyze them. Image-to-image seams have been eliminated from the sky portion of the mosaic to better simulate the vista a person standing on Mars would see.

  17. Efficient high-quality volume rendering of SPH data.

    PubMed

    Fraedrich, Roland; Auer, Stefan; Westermann, Rüdiger

    2010-01-01

    High quality volume rendering of SPH data requires a complex order-dependent resampling of particle quantities along the view rays. In this paper we present an efficient approach to perform this task using a novel view-space discretization of the simulation domain. Our method draws upon recent work on GPU-based particle voxelization for the efficient resampling of particles into uniform grids. We propose a new technique that leverages a perspective grid to adaptively discretize the view-volume, giving rise to a continuous level-of-detail sampling structure and reducing memory requirements compared to a uniform grid. In combination with a level-of-detail representation of the particle set, the perspective grid allows effectively reducing the amount of primitives to be processed at run-time. We demonstrate the quality and performance of our method for the rendering of fluid and gas dynamics SPH simulations consisting of many millions of particles.

  18. Conjoint analysis to measure the perceived quality in volume rendering.

    PubMed

    Giesen, Joachim; Mueller, Klaus; Schuberth, Eva; Wang, Lujin; Zolliker, Peter

    2007-01-01

    Visualization algorithms can have a large number of parameters, making the space of possible rendering results rather high-dimensional. Only a systematic analysis of the perceived quality can truly reveal the optimal setting for each such parameter. However, an exhaustive search in which all possible parameter permutations are presented to each user within a study group would be infeasible to conduct. Additional complications may result from possible parameter co-dependencies. Here, we will introduce an efficient user study design and analysis strategy that is geared to cope with this problem. The user feedback is fast and easy to obtain and does not require exhaustive parameter testing. To enable such a framework we have modified a preference measuring methodology, conjoint analysis, that originated in psychology and is now also widely used in market research. We demonstrate our framework by a study that measures the perceived quality in volume rendering within the context of large parameter spaces.

  19. The shock response of a rendered porcine fat

    NASA Astrophysics Data System (ADS)

    Wilgeroth, J. M.; Hazell, P. J.; Appleby-Thomas, G. J.

    2010-11-01

    Characterization of the shock response of biological materials is required in order to develop an understanding of how such materials behave under high strain-rate loading. In this work, a predominately linear Us-up Hugoniot relationship for a rendered porcine fat has been established using the plate-impact technique. This has been shown to take the form Us=1.58+2.47up (ρ0=0.945 g/cc) and comparison has been made between the dynamic behavior of the adipose material and both 20 wt % ballistic gelatin and water. The adipose material has been shown to behave in likeness with simple polymers such as polyethylene and to strengthen under shock loading, unlike ballistic gelatin, which has been shown to behave hydrodynamically. An experimental design incorporating direct insertion of lateral stress gauges within the rendered fat has given insight into both the behavior of lateral gauges and the lateral stress response of the material under dynamic loading.

  20. Generalized pipeline for preview and rendering of synthetic holograms

    NASA Astrophysics Data System (ADS)

    Pappu, Ravikanth; Sparrell, Carlton J.; Underkoffler, John S.; Kropp, Adam B.; Chen, Benjie; Plesniak, Wendy J.

    1997-04-01

    We describe a general pipeline for the computation and display of either fully-computed holograms or holographic stereograms using the same 3D database. A rendering previewer on a Silicon Graphics Onyx allows a user to specify viewing geometry, database transformations, and scene lighting. The previewer then generates one of two descriptions of the object--a series of perspective views or a polygonal model--which is then used by a fringe rendering engine to compute fringes specific to hologram type. The images are viewed on the second generation MIT Holographic Video System. This allows a viewer to compare holographic stereograms with fully-computed holograms originating from the same database and comes closer to the goal of a single pipeline being able to display the same data in different formats.

  1. Rapid exploration of curvilinear grids using direct volume rendering

    NASA Technical Reports Server (NTRS)

    Vangelder, Allen; Wilhelms, Jane

    1993-01-01

    Fast techniques for direct volume rendering over curvilinear grids of hexahedral cells are developed. This type of 3D grid is common in computational fluid dynamics and finite element analysis. Four new projection methods are presented and compared with each other and with previous methods for tetrahedral grids and rectilinear grids. All four methods use polygon-rendering hardware for speed. A simplified algorithm for visibility ordering, which is based on a combination of breadth-first and depth-first searches, is described. A new multi-pass blending method is described that reduces visual artifacts that are introduced by linear interpolation in hardware where exponential interpolation is needed. Multi-pass blending is of equal interest to hardware-oriented projection methods used on rectilinear grids. Visualization tools that permit rapid data banding and cycling through transfer functions, as well as region restrictions, are described.

  2. Vibration rendering on a thin plate with actuator array at the periphery

    NASA Astrophysics Data System (ADS)

    Woo, Jung-Han; Ih, Jeong-Guon

    2015-08-01

    Vibrations are rendered on the display panel of a mobile electronic device to transfer a tactile sensation to users. Because important electronic components are usually positioned in the central part of the devices, the only practical choice for actuator location is the periphery of the panel although the periphery is not the advantageous position for the excitation. As the basic principle to generate a rendered vibration pattern, two methods to determine the contributions of modes, viz., eigenfunction superposition or traveling wave control method, are implemented individually. The purpose is to generate a pattern of vibration amplitudes that can be felt by fingertip in the hot zone but not in the cold zone, which is outside the hot zone. General inverse methods are applied to obtain the actuator weightings for achieving the target pattern. Proper weighting for both amplitude and phase for each actuator in the array is determined by the relationship between modes or velocity responses and input signals of actuators. Two methods are implemented individually on the display panel of a commercial tablet computer using an array of moving-coil actuators, and the responses on the panel are measured. Performance index referred to as success ratio for evaluating satisfaction of target field constraints is proposed considering the different thresholds of vibration sensation. Reasonable fulfillment of achieving the target vibration pattern is observed experimentally. The success ratio is more than 86% by using the eigenfunction superposition, and more than 97% by using the traveling wave control for rendering 2×2 and 3×3 section.

  3. FluoRender: An Application of 2D Image Space Methods for 3D and 4D Confocal Microscopy Data Visualization in Neurobiology Research

    PubMed Central

    Wan, Yong; Otsuna, Hideo; Chien, Chi-Bin; Hansen, Charles

    2013-01-01

    2D image space methods are processing methods applied after the volumetric data are projected and rendered into the 2D image space, such as 2D filtering, tone mapping and compositing. In the application domain of volume visualization, most 2D image space methods can be carried out more efficiently than their 3D counterparts. Most importantly, 2D image space methods can be used to enhance volume visualization quality when applied together with volume rendering methods. In this paper, we present and discuss the applications of a series of 2D image space methods as enhancements to confocal microscopy visualizations, including 2D tone mapping, 2D compositing, and 2D color mapping. These methods are easily integrated with our existing confocal visualization tool, FluoRender, and the outcome is a full-featured visualization system that meets neurobiologists’ demands for qualitative analysis of confocal microscopy data. PMID:23584131

  4. FluoRender: An Application of 2D Image Space Methods for 3D and 4D Confocal Microscopy Data Visualization in Neurobiology Research.

    PubMed

    Wan, Yong; Otsuna, Hideo; Chien, Chi-Bin; Hansen, Charles

    2012-01-01

    2D image space methods are processing methods applied after the volumetric data are projected and rendered into the 2D image space, such as 2D filtering, tone mapping and compositing. In the application domain of volume visualization, most 2D image space methods can be carried out more efficiently than their 3D counterparts. Most importantly, 2D image space methods can be used to enhance volume visualization quality when applied together with volume rendering methods. In this paper, we present and discuss the applications of a series of 2D image space methods as enhancements to confocal microscopy visualizations, including 2D tone mapping, 2D compositing, and 2D color mapping. These methods are easily integrated with our existing confocal visualization tool, FluoRender, and the outcome is a full-featured visualization system that meets neurobiologists' demands for qualitative analysis of confocal microscopy data.

  5. Efficient Encoding and Rendering of Time-Varying Volume Data

    NASA Technical Reports Server (NTRS)

    Ma, Kwan-Liu; Smith, Diann; Shih, Ming-Yun; Shen, Han-Wei

    1998-01-01

    Visualization of time-varying volumetric data sets, which may be obtained from numerical simulations or sensing instruments, provides scientists insights into the detailed dynamics of the phenomenon under study. This paper describes a coherent solution based on quantization, coupled with octree and difference encoding for visualizing time-varying volumetric data. Quantization is used to attain voxel-level compression and may have a significant influence on the performance of the subsequent encoding and visualization steps. Octree encoding is used for spatial domain compression, and difference encoding for temporal domain compression. In essence, neighboring voxels may be fused into macro voxels if they have similar values, and subtrees at consecutive time steps may be merged if they are identical. The software rendering process is tailored according to the tree structures and the volume visualization process. With the tree representation, selective rendering may be performed very efficiently. Additionally, the I/O costs are reduced. With these combined savings, a higher level of user interactivity is achieved. We have studied a variety of time-varying volume datasets, performed encoding based on data statistics, and optimized the rendering calculations wherever possible. Preliminary tests on workstations have shown in many cases tremendous reduction by as high as 90% in both storage space and inter-frame delay.

  6. Real-time rendering of optical effects using spatial convolution

    NASA Astrophysics Data System (ADS)

    Rokita, Przemyslaw

    1998-03-01

    Simulation of special effects such as: defocus effect, depth-of-field effect, raindrops or water film falling on the windshield, may be very useful in visual simulators and in all computer graphics applications that need realistic images of outdoor scenery. Those effects are especially important in rendering poor visibility conditions in flight and driving simulators, but can also be applied, for example, in composing computer graphics and video sequences- -i.e. in Augmented Reality systems. This paper proposes a new approach to the rendering of those optical effects by iterative adaptive filtering using spatial convolution. The advantage of this solution is that the adaptive convolution can be done in real-time by existing hardware. Optical effects mentioned above can be introduced into the image computed using conventional camera model by applying to the intensity of each pixel the convolution filter having an appropriate point spread function. The algorithms described in this paper can be easily implemented int the visualization pipeline--the final effect may be obtained by iterative filtering using a single hardware convolution filter or with the pipeline composed of identical 3 X 3 filters placed as the stages of this pipeline. Another advantage of the proposed solution is that the extension based on proposed algorithm can be added to the existing rendering systems as a final stage of the visualization pipeline.

  7. High Performance GPU-Based Fourier Volume Rendering

    PubMed Central

    Abdellah, Marwan; Eldeib, Ayman; Sharawi, Amr

    2015-01-01

    Fourier volume rendering (FVR) is a significant visualization technique that has been used widely in digital radiography. As a result of its 𝒪(N2log⁡N) time complexity, it provides a faster alternative to spatial domain volume rendering algorithms that are 𝒪(N3) computationally complex. Relying on the Fourier projection-slice theorem, this technique operates on the spectral representation of a 3D volume instead of processing its spatial representation to generate attenuation-only projections that look like X-ray radiographs. Due to the rapid evolution of its underlying architecture, the graphics processing unit (GPU) became an attractive competent platform that can deliver giant computational raw power compared to the central processing unit (CPU) on a per-dollar-basis. The introduction of the compute unified device architecture (CUDA) technology enables embarrassingly-parallel algorithms to run efficiently on CUDA-capable GPU architectures. In this work, a high performance GPU-accelerated implementation of the FVR pipeline on CUDA-enabled GPUs is presented. This proposed implementation can achieve a speed-up of 117x compared to a single-threaded hybrid implementation that uses the CPU and GPU together by taking advantage of executing the rendering pipeline entirely on recent GPU architectures. PMID:25866499

  8. A novel method for color correction in epiluminescence microscopy.

    PubMed

    Quintana, Josep; Garcia, Rafael; Neumann, László

    2011-01-01

    This paper proposes a new color correction pipeline to improve the dermoscopy image quality. Images acquired with different cameras or different dermoscopes often present problems of faithful color reproduction. The colors of these images are often far different the ones observed with the naked eye, and usually vary from one camera to another. Nowadays digital cameras perform "black-box" color corrections taking into account the color temperature of the imaged scene, which may result in some cases in unrealistic color rendering. For this reason, it is necessary to calibrate the imaging system (the camera and a specific dermoscope). The calibration process requires finding a relationship between a device-dependent color space and a standard color space depending only on the human eye. This relation is obtained acquiring known color patches of a color checker and relating them with the pixel values obtained by the camera. In our approach we model the color calibration problem using a new formulation that takes into account the spectral distribution of the dermoscope lighting system and conveys a solution for both RAW and JPEG images. When comparing images captured with different cameras, this new method improves the results between 0.1 and 0.9 ΔE with respect to previous approaches.

  9. A novel method for color correction in epiluminescence microscopy.

    PubMed

    Quintana, Josep; Garcia, Rafael; Neumann, László

    2011-01-01

    This paper proposes a new color correction pipeline to improve the dermoscopy image quality. Images acquired with different cameras or different dermoscopes often present problems of faithful color reproduction. The colors of these images are often far different the ones observed with the naked eye, and usually vary from one camera to another. Nowadays digital cameras perform "black-box" color corrections taking into account the color temperature of the imaged scene, which may result in some cases in unrealistic color rendering. For this reason, it is necessary to calibrate the imaging system (the camera and a specific dermoscope). The calibration process requires finding a relationship between a device-dependent color space and a standard color space depending only on the human eye. This relation is obtained acquiring known color patches of a color checker and relating them with the pixel values obtained by the camera. In our approach we model the color calibration problem using a new formulation that takes into account the spectral distribution of the dermoscope lighting system and conveys a solution for both RAW and JPEG images. When comparing images captured with different cameras, this new method improves the results between 0.1 and 0.9 ΔE with respect to previous approaches. PMID:21531539

  10. Realizing Rec. 2020 color gamut with quantum dot displays.

    PubMed

    Zhu, Ruidong; Luo, Zhenyue; Chen, Haiwei; Dong, Yajie; Wu, Shin-Tson

    2015-09-01

    We analyze how to realize Rec. 2020 wide color gamut with quantum dots. For photoluminescence, our simulation indicates that we are able to achieve over 97% of the Rec. 2020 standard with quantum dots by optimizing the emission spectra and redesigning the color filters. For electroluminescence, by optimizing the emission spectra of quantum dots is adequate to render over 97% of the Rec. 2020 standard. We also analyze the efficiency and angular performance of these devices, and then compare results with LCDs using green and red phosphors-based LED backlight. Our results indicate that quantum dot display is an outstanding candidate for achieving wide color gamut and high optical efficiency.

  11. Scanning color optical tomography (SCOT)

    PubMed Central

    Hosseini, Poorya; Sung, Yongjin; Choi, Youngwoon; Lue, Niyom; Yaqoob, Zahid; So, Peter

    2015-01-01

    We have developed an interferometric optical microscope that provides three-dimensional refractive index map of a specimen by scanning the color of three illumination beams. Our design of the interferometer allows for simultaneous measurement of the scattered fields (both amplitude and phase) of such a complex input beam. By obviating the need for mechanical scanning of the illumination beam or detection objective lens; the proposed method can increase the speed of the optical tomography by orders of magnitude. We demonstrate our method using polystyrene beads of known refractive index value and live cells. PMID:26367632

  12. Scanning color optical tomography (SCOT).

    PubMed

    Hosseini, Poorya; Sung, Yongjin; Choi, Youngwoon; Lue, Niyom; Yaqoob, Zahid; So, Peter

    2015-07-27

    We have developed an interferometric optical microscope that provides three-dimensional refractive index map of a specimen by scanning the color of three illumination beams. Our design of the interferometer allows for simultaneous measurement of the scattered fields (both amplitude and phase) of such a complex input beam. By obviating the need for mechanical scanning of the illumination beam or detection objective lens; the proposed method can increase the speed of the optical tomography by orders of magnitude. We demonstrate our method using polystyrene beads of known refractive index value and live cells. PMID:26367632

  13. Masking the Color Wheel.

    ERIC Educational Resources Information Center

    Greene, Charlene

    1982-01-01

    Describes an art activity in which sixth graders made mirror-image masks using only two primary colors and one secondary color. Students discussed the effect of color combinations and the use of masks in folk and modern cultures. (AM)

  14. LED Color Characteristics

    SciTech Connect

    2012-01-01

    Color quality is an important consideration when evaluating LED-based products for general illumination. This fact sheet reviews the basics regarding light and color and summarizes the most important color issues related to white-light LED systems.

  15. Spatio-temporal visualization of air-sea CO2 flux and carbon budget using volume rendering

    NASA Astrophysics Data System (ADS)

    Du, Zhenhong; Fang, Lei; Bai, Yan; Zhang, Feng; Liu, Renyi

    2015-04-01

    This paper presents a novel visualization method to show the spatio-temporal dynamics of carbon sinks and sources, and carbon fluxes in the ocean carbon cycle. The air-sea carbon budget and its process of accumulation are demonstrated in the spatial dimension, while the distribution pattern and variation of CO2 flux are expressed by color changes. In this way, we unite spatial and temporal characteristics of satellite data through visualization. A GPU-based direct volume rendering technique using half-angle slicing is adopted to dynamically visualize the released or absorbed CO2 gas with shadow effects. A data model is designed to generate four-dimensional (4D) data from satellite-derived air-sea CO2 flux products, and an out-of-core scheduling strategy is also proposed for on-the-fly rendering of time series of satellite data. The presented 4D visualization method is implemented on graphics cards with vertex, geometry and fragment shaders. It provides a visually realistic simulation and user interaction for real-time rendering. This approach has been integrated into the Information System of Ocean Satellite Monitoring for Air-sea CO2 Flux (IssCO2) for the research and assessment of air-sea CO2 flux in the China Seas.

  16. Basic Color Theory and Color in Computers.

    ERIC Educational Resources Information Center

    Stroh, Charles

    1997-01-01

    Discusses the nature of light and its relationship to color, particularly two models of color production: the additive and subtractive models. Explains the importance of these models for understanding how computers and printers generate colors. Argues that it is important to understand these processes given the prevalence of computers in art. (DSK)

  17. Autophagy supports color vision.

    PubMed

    Zhou, Zhenqing; Vinberg, Frans; Schottler, Frank; Doggett, Teresa A; Kefalov, Vladimir J; Ferguson, Thomas A

    2015-01-01

    Cones comprise only a small portion of the photoreceptors in mammalian retinas. However, cones are vital for color vision and visual perception, and their loss severely diminishes the quality of life for patients with retinal degenerative diseases. Cones function in bright light and have higher demand for energy than rods; yet, the mechanisms that support the energy requirements of cones are poorly understood. One such pathway that potentially could sustain cones under basal and stress conditions is macroautophagy. We addressed the role of macroautophagy in cones by examining how the genetic block of this pathway affects the structural integrity, survival, and function of these neurons. We found that macroautophagy was not detectable in cones under normal conditions but was readily observed following 24 h of fasting. Consistent with this, starvation induced phosphorylation of AMPK specifically in cones indicating cellular starvation. Inhibiting macroautophagy in cones by deleting the essential macroautophagy gene Atg5 led to reduced cone function following starvation suggesting that cones are sensitive to systemic changes in nutrients and activate macroautophagy to maintain their function. ATG5-deficiency rendered cones susceptible to light-induced damage and caused accumulation of damaged mitochondria in the inner segments, shortening of the outer segments, and degeneration of all cone types, revealing the importance of mitophagy in supporting cone metabolic needs. Our results demonstrate that macroautophagy supports the function and long-term survival of cones providing for their unique metabolic requirements and resistance to stress. Targeting macroautophagy has the potential to preserve cone-mediated vision during retinal degenerative diseases. PMID:26292183

  18. Autophagy supports color vision

    PubMed Central

    Zhou, Zhenqing; Vinberg, Frans; Schottler, Frank; Doggett, Teresa A; Kefalov, Vladimir J; Ferguson, Thomas A

    2015-01-01

    Cones comprise only a small portion of the photoreceptors in mammalian retinas. However, cones are vital for color vision and visual perception, and their loss severely diminishes the quality of life for patients with retinal degenerative diseases. Cones function in bright light and have higher demand for energy than rods; yet, the mechanisms that support the energy requirements of cones are poorly understood. One such pathway that potentially could sustain cones under basal and stress conditions is macroautophagy. We addressed the role of macroautophagy in cones by examining how the genetic block of this pathway affects the structural integrity, survival, and function of these neurons. We found that macroautophagy was not detectable in cones under normal conditions but was readily observed following 24 h of fasting. Consistent with this, starvation induced phosphorylation of AMPK specifically in cones indicating cellular starvation. Inhibiting macroautophagy in cones by deleting the essential macroautophagy gene Atg5 led to reduced cone function following starvation suggesting that cones are sensitive to systemic changes in nutrients and activate macroautophagy to maintain their function. ATG5-deficiency rendered cones susceptible to light-induced damage and caused accumulation of damaged mitochondria in the inner segments, shortening of the outer segments, and degeneration of all cone types, revealing the importance of mitophagy in supporting cone metabolic needs. Our results demonstrate that macroautophagy supports the function and long-term survival of cones providing for their unique metabolic requirements and resistance to stress. Targeting macroautophagy has the potential to preserve cone-mediated vision during retinal degenerative diseases. PMID:26292183

  19. Autophagy supports color vision.

    PubMed

    Zhou, Zhenqing; Vinberg, Frans; Schottler, Frank; Doggett, Teresa A; Kefalov, Vladimir J; Ferguson, Thomas A

    2015-01-01

    Cones comprise only a small portion of the photoreceptors in mammalian retinas. However, cones are vital for color vision and visual perception, and their loss severely diminishes the quality of life for patients with retinal degenerative diseases. Cones function in bright light and have higher demand for energy than rods; yet, the mechanisms that support the energy requirements of cones are poorly understood. One such pathway that potentially could sustain cones under basal and stress conditions is macroautophagy. We addressed the role of macroautophagy in cones by examining how the genetic block of this pathway affects the structural integrity, survival, and function of these neurons. We found that macroautophagy was not detectable in cones under normal conditions but was readily observed following 24 h of fasting. Consistent with this, starvation induced phosphorylation of AMPK specifically in cones indicating cellular starvation. Inhibiting macroautophagy in cones by deleting the essential macroautophagy gene Atg5 led to reduced cone function following starvation suggesting that cones are sensitive to systemic changes in nutrients and activate macroautophagy to maintain their function. ATG5-deficiency rendered cones susceptible to light-induced damage and caused accumulation of damaged mitochondria in the inner segments, shortening of the outer segments, and degeneration of all cone types, revealing the importance of mitophagy in supporting cone metabolic needs. Our results demonstrate that macroautophagy supports the function and long-term survival of cones providing for their unique metabolic requirements and resistance to stress. Targeting macroautophagy has the potential to preserve cone-mediated vision during retinal degenerative diseases.

  20. Irregular Morphing for Real-Time Rendering of Large Terrain

    NASA Astrophysics Data System (ADS)

    Kalem, Sid'Ali; Kourgli, Assia

    2016-06-01

    The following paper proposes an alternative approach to the real-time adaptive triangulation problem. A new region-based multi-resolution approach for terrain rendering is described which improves on-the-fly the distribution of the density of triangles inside the tile after selecting appropriate Level-Of-Detail by an adaptive sampling. This proposed approach organizes the heightmap into a QuadTree of tiles that are processed independently. This technique combines the benefits of both Triangular Irregular Network approach and region-based multi-resolution approach by improving the distribution of the density of triangles inside the tile. Our technique morphs the initial regular grid of the tile to deformed grid in order to minimize approximation error. The proposed technique strives to combine large tile size and real-time processing while guaranteeing an upper bound on the screen space error. Thus, this approach adapts terrain rendering process to local surface characteristics and enables on-the-fly handling of large amount of terrain data. Morphing is based-on the multi-resolution wavelet analysis. The use of the D2WT multi-resolution analysis of the terrain height-map speeds up processing and permits to satisfy an interactive terrain rendering. Tests and experiments demonstrate that Haar B-Spline wavelet, well known for its properties of localization and its compact support, is suitable for fast and accurate redistribution. Such technique could be exploited in client-server architecture for supporting interactive high-quality remote visualization of very large terrain.

  1. A survey on hair modeling: styling, simulation, and rendering.

    PubMed

    Ward, Kelly; Bertails, Florence; Kim, Tae-Yong; Marschner, Stephen R; Cani, Marie-Paule; Lin, Ming C

    2007-01-01

    Realistic hair modeling is a fundamental part of creating virtual humans in computer graphics. This paper surveys the state of the art in the major topics of hair modeling: hairstyling, hair simulation, and hair rendering. Because of the difficult, often unsolved problems that arise in all these areas, a broad diversity of approaches are used, each with strengths that make it appropriate for particular applications. We discuss each of these major topics in turn, presenting the unique challenges facing each area and describing solutions that have been presented over the years to handle these complex issues. Finally, we outline some of the remaining computational challenges in hair modeling.

  2. Interactive View-Dependent Rendering of Large Iso-Surfaces

    SciTech Connect

    Gregorski, B.; Duchaineau, M.A.; Lindstrom, P.; Pascucci, V.; Joy, K.J.

    2002-01-11

    The authors present an algorithm for interactively extracting and rendering iso-surfaces of large volume datasets in a view-dependent optimal fashion. A recursive tetrahedral mesh subdivision scheme, based on longest edge bisection, is used to hierarchically decompose the data into a multi-resolution structure. This data structure allows fast extraction of arbitrary iso-surfaces to within user specified view-dependent error bounds. A compact encoding of the mesh subdivision optimizes memory usage and processor performance necessary for large datasets. A data layout scheme based on hierarchical space filling curves provides optimal access to the data in a cache coherent manner.

  3. A survey on hair modeling: styling, simulation, and rendering.

    PubMed

    Ward, Kelly; Bertails, Florence; Kim, Tae-Yong; Marschner, Stephen R; Cani, Marie-Paule; Lin, Ming C

    2007-01-01

    Realistic hair modeling is a fundamental part of creating virtual humans in computer graphics. This paper surveys the state of the art in the major topics of hair modeling: hairstyling, hair simulation, and hair rendering. Because of the difficult, often unsolved problems that arise in all these areas, a broad diversity of approaches are used, each with strengths that make it appropriate for particular applications. We discuss each of these major topics in turn, presenting the unique challenges facing each area and describing solutions that have been presented over the years to handle these complex issues. Finally, we outline some of the remaining computational challenges in hair modeling. PMID:17218740

  4. Interactive View-Dependent Rendering of Large Isosurfaces

    SciTech Connect

    Gregorski, B; Duchaineau, M; Lindstrom, P; Pascucci, V; Joy, K I

    2002-11-19

    We present an algorithm for interactively extracting and rendering isosurfaces of large volume datasets in a view-dependent fashion. A recursive tetrahedral mesh refinement scheme, based on longest edge bisection, is used to hierarchically decompose the data into a multiresolution structure. This data structure allows fast extraction of arbitrary isosurfaces to within user specified view-dependent error bounds. A data layout scheme based on hierarchical space filling curves provides access to the data in a cache coherent manner that follows the data access pattern indicated by the mesh refinement.

  5. An example of quantum imaging: rendering an object undetectable

    NASA Astrophysics Data System (ADS)

    Ataman, Stefan

    2016-06-01

    In this paper we propose and analyse a Gedankenexperiment involving three non-linear crystals and two objects inserted in the idler beams. We show that, besides the behaviour that can be extrapolated from previous experiments involving two crystals and one object, we are able to predict a new effect: under certain circumstances, one of the objects can be rendered undetectable to any single detection rate on the signal photons with discarded idler photons. This effect could find applications in future developments of quantum imaging techniques.

  6. Color images of Kansas subsurface geology from well logs

    USGS Publications Warehouse

    Collins, D.R.; Doveton, J.H.

    1986-01-01

    Modern wireline log combinations give highly diagnostic information that goes beyond the basic shale content, pore volume, and fluid saturation of older logs. Pattern recognition of geology from logs is made conventionally through either the examination of log overlays or log crossplots. Both methods can be combined through the use of color as a medium of information by setting the three color primaries of blue, green, and red light as axes of three dimensional color space. Multiple log readings of zones are rendered as composite color mixtures which, when plotted sequentially with depth, show lithological successions in a striking manner. The method is extremely simple to program and display on a color monitor. Illustrative examples are described from the Kansas subsurface. ?? 1986.

  7. Study on color-tunable phosphor-coated white light-emitting diodes with high S/P ratios

    NASA Astrophysics Data System (ADS)

    Guo, Ziquan; Shih, Tienmo; Xiao, Jingjing; Lu, Hongli; Lu, Yijun; Wu, Tingzhu; Lin, Yue; Gao, Yulin; Xiao, Hua; Chen, Zhong

    2016-03-01

    In this study, we have investigated the trade-off between the color rendering index (CRI, Ra) and the scotopic/photopic ratio (S/P) for color-tunable phosphor-coated white light-emitting diodes (LEDs) at two CRI limitations (Ra ≥ 70 and Ra ≥ 96). First, luminescent spectra measurements have been conducted to determine experimental results of Ra and S/P under various correlated color temperatures (CCTs). Then, a nonlinear programming method has been adopted for the optimization of Ra and S/P by varying spectral shapes through adjusting spectral parameters, such as peak wavelengths, full-width at half-maxima, and relative intensities. Therefore, polynomial curves of optimal S/P versus CCT at two Ra limitations have been discovered, enabling users to obtain optimal S/P under arbitrary CCTs within [2700 K, 6500 K]. In addition, a comparison study between the present work and our previous work has also been conducted at Ra = 70, and a fair agreement of optimal S/P has been observed.

  8. Development of the RGB LEDs color mixing mechanism for stability the color temperature at different projection distances.

    PubMed

    Hung, Chih-Ching

    2015-01-01

    In lighting application, the color mixing of the RGB LEDs can provide more color selection in correlated color temperature and color rendering. Therefore, the purpose of this study is to propose a RGB color mixing mechanism by applying the mechanism design. Three sets of lamp-type RGB LEDs are individually installed on three four-bar linkages. A crank is used to drive three groups of RGB LEDs lamp-type to project lights onto a single plane in order to mix the lights. And, simulations of the illuminance and associated color temperatures are conducted by changing the distance to the projection plane, under the assumption that the stability of the color temperature of the projected light does not change according to the projecting height. Thus, the effect of change in the color temperature on color determination by the humans' eyes was avoided. The success of the proposed method will allow medical personnel to choose suitable wavelengths and color temperatures according to the particular requirements of their medical-examination environments. PMID:26444810

  9. Development of the RGB LEDs color mixing mechanism for stability the color temperature at different projection distances.

    PubMed

    Hung, Chih-Ching

    2015-01-01

    In lighting application, the color mixing of the RGB LEDs can provide more color selection in correlated color temperature and color rendering. Therefore, the purpose of this study is to propose a RGB color mixing mechanism by applying the mechanism design. Three sets of lamp-type RGB LEDs are individually installed on three four-bar linkages. A crank is used to drive three groups of RGB LEDs lamp-type to project lights onto a single plane in order to mix the lights. And, simulations of the illuminance and associated color temperatures are conducted by changing the distance to the projection plane, under the assumption that the stability of the color temperature of the projected light does not change according to the projecting height. Thus, the effect of change in the color temperature on color determination by the humans' eyes was avoided. The success of the proposed method will allow medical personnel to choose suitable wavelengths and color temperatures according to the particular requirements of their medical-examination environments.

  10. Stellar ultraviolet colors and interstellar extinction

    NASA Technical Reports Server (NTRS)

    Peytremann, E.; Davis, R. J.

    1972-01-01

    A sample of celescope results is studied. Most of the sample stars belong to the Orion and Vela regions. Stars with visual excess E(B-V) less than 0.05 are selected in order to derive relationships of intrinsic color index versus spectral type. The resulting intrinsic color-color relations are compared with existing blanketed and unblanketed model calculations. Finally, the preceding intrinsic relations are utilized to derive some results on interstellar extinction. Owing to the rather large scatter in the celescope data, the Vela stars give the more significant results because their visible excess E(B-V) is, in general, larger than that for the Orion stars.

  11. Tomographic image reconstruction and rendering with texture-mapping hardware

    SciTech Connect

    Azevedo, S.G.; Cabral, B.K.; Foran, J.

    1994-07-01

    The image reconstruction problem, also known as the inverse Radon transform, for x-ray computed tomography (CT) is found in numerous applications in medicine and industry. The most common algorithm used in these cases is filtered backprojection (FBP), which, while a simple procedure, is time-consuming for large images on any type of computational engine. Specially-designed, dedicated parallel processors are commonly used in medical CT scanners, whose results are then passed to graphics workstation for rendering and analysis. However, a fast direct FBP algorithm can be implemented on modern texture-mapping hardware in current high-end workstation platforms. This is done by casting the FBP algorithm as an image warping operation with summing. Texture-mapping hardware, such as that on the Silicon Graphics Reality Engine (TM), shows around 600 times speedup of backprojection over a CPU-based implementation (a 100 Mhz R4400 in this case). This technique has the further advantages of flexibility and rapid programming. In addition, the same hardware can be used for both image reconstruction and for volumetric rendering. The techniques can also be used to accelerate iterative reconstruction algorithms. The hardware architecture also allows more complex operations than straight-ray backprojection if they are required, including fan-beam, cone-beam, and curved ray paths, with little or no speed penalties.

  12. Tomographic image reconstruction and rendering with texture-mapping hardware

    NASA Astrophysics Data System (ADS)

    Azevedo, Stephen G.; Cabral, Brian K.; Foran, Jim

    1994-07-01

    The image reconstruction problem, also known as the inverse Radon transform, for x-ray computed tomography (CT) is found in numerous applications in medicine and industry. The most common algorithm used in these cases is filtered backprojection (FBP), which, while a simple procedure, is time-consuming for large images on any type of computational engine. Specially designed, dedicated parallel processors are commonly used in medical CT scanners, whose results are then passed to a graphics workstation for rendering and analysis. However, a fast direct FBP algorithm can be implemented on modern texture-mapping hardware in current high-end workstation platforms. This is done by casting the FBP algorithm as an image warping operation with summing. Texture- mapping hardware, such as that on the silicon Graphics Reality Engine, shows around 600 times speedup of backprojection over a CPU-based implementation (a 100 Mhz R4400 in our case). This technique has the further advantages of flexibility and rapid programming. In addition, the same hardware can be used for both image reconstruction and for volumetric rendering. Our technique can also be used to accelerate iterative reconstruction algorithms. The hardware architecture also allows more complex operations than straight-ray backprojection if they are required, including fan-beam, cone-beam, and curved ray paths, with little or no speed penalties.

  13. Rendering energy-conservative scenes in real time

    NASA Astrophysics Data System (ADS)

    Olson, Eric M.; Garbo, Dennis L.; Crow, Dennis R.; Coker, Charles F.

    1997-07-01

    Real-time infrared (IR) scene generation from HardWare-in- the-Loop (HWIL) testing of IR seeker systems is a complex problem due to the required frame rates and image fidelity. High frame rates are required for current generation seeker systems to perform designation, discrimination, identification, tracking, and aimpoint selection tasks. Computational requirements for IR signature phenomenology and sensor effects have been difficult to perform in real- time to support HWIL testing. Commercial scene generation hardware is rapidly improving and is becoming a viable solution for HWIL testing activities being conducted at the Kinetic Kill Vehicle Hardware-in-the-Loop Simulator facility at Eglin AFB, Florida. This paper presents computational techniques performed to overcome IR scene rendering errors incurred with commercially available hardware and software for real-time scene generation in support of HWIL testing. These techniques provide an acceptable solution to real-time IR scene generation that strikes a balance between physical accuracy and image framing rates. The results of these techniques are investigated as they pertain to rendering accuracy and speed for target objects which begin as a point source during acquisition and develop into an extended source representation during aimpoint selection.

  14. The rendering context for stereoscopic 3D web

    NASA Astrophysics Data System (ADS)

    Chen, Qinshui; Wang, Wenmin; Wang, Ronggang

    2014-03-01

    3D technologies on the Web has been studied for many years, but they are basically monoscopic 3D. With the stereoscopic technology gradually maturing, we are researching to integrate the binocular 3D technology into the Web, creating a stereoscopic 3D browser that will provide users with a brand new experience of human-computer interaction. In this paper, we propose a novel approach to apply stereoscopy technologies to the CSS3 3D Transforms. Under our model, each element can create or participate in a stereoscopic 3D rendering context, in which 3D Transforms such as scaling, translation and rotation, can be applied and be perceived in a truly 3D space. We first discuss the underlying principles of stereoscopy. After that we discuss how these principles can be applied to the Web. A stereoscopic 3D browser with backward compatibility is also created for demonstration purposes. We take advantage of the open-source WebKit project, integrating the 3D display ability into the rendering engine of the web browser. For each 3D web page, our 3D browser will create two slightly different images, each representing the left-eye view and right-eye view, both to be combined on the 3D display to generate the illusion of depth. And as the result turns out, elements can be manipulated in a truly 3D space.

  15. Realistic haptic rendering of interacting deformable objects in virtual environments.

    PubMed

    Duriez, Christian; Dubois, Frédéric; Kheddar, Abderrahmane; Andriot, Claude

    2006-01-01

    A new computer haptics algorithm to be used in general interactive manipulations of deformable virtual objects is presented. In multimodal interactive simulations, haptic feedback computation often comes from contact forces. Subsequently, the fidelity of haptic rendering depends significantly on contact space modeling. Contact and friction laws between deformable models are often simplified in up to date methods. They do not allow a "realistic" rendering of the subtleties of contact space physical phenomena (such as slip and stick effects due to friction or mechanical coupling between contacts). In this paper, we use Signorini's contact law and Coulomb's friction law as a computer haptics basis. Real-time performance is made possible thanks to a linearization of the behavior in the contact space, formulated as the so-called Delassus operator, and iteratively solved by a Gauss-Seidel type algorithm. Dynamic deformation uses corotational global formulation to obtain the Delassus operator in which the mass and stiffness ratio are dissociated from the simulation time step. This last point is crucial to keep stable haptic feedback. This global approach has been packaged, implemented, and tested. Stable and realistic 6D haptic feedback is demonstrated through a clipping task experiment. PMID:16382606

  16. Protein and mineral characterisation of rendered meat and bone meal.

    PubMed

    Buckley, M; Penkman, K E H; Wess, T J; Reaney, S; Collins, M J

    2012-10-01

    We report the characterisation of meat and bone meal (MBM) standards (Set B-EFPRA) derived from cattle, sheep, pig and chicken, each rendered at four different temperatures (133, 137, 141 and 145 °C). The standards, prepared for an EU programme STRATFEED (to develop new methodologies for the detection and quantification of illegal addition of mammalian tissues in feeding stuffs), have been widely circulated and used to assess a range of methods for identification of the species composition of MBM. The overall state of mineral alteration and protein preservation as a function of temperature was monitored using small angle X-ray diffraction (SAXS), amino acid composition and racemization analyses. Progressive increases in protein damage and mineral alteration in chicken and cattle standards was observed. In the case of sheep and pig, there was greater damage to the proteins and alteration of the minerals at the lowest treatment temperature (133 °C), suggesting that the thermal treatments must have been compromised in some way. This problem has probably impacted upon the numerous studies which tested methods against these heat treatments. We use protein mass spectrometric methods to explore if thermostable proteins could be used to identify rendered MBM. In more thermally altered samples, so-called 'thermostable' proteins such as osteocalcin which has been proposed as a ideal target to speciate MBM were no longer detectable, but the structural protein type I collagen could be used to differentiate all four species, even in the most thermally altered samples.

  17. Hardware-accelerated autostereogram rendering for interactive 3D visualization

    NASA Astrophysics Data System (ADS)

    Petz, Christoph; Goldluecke, Bastian; Magnor, Marcus

    2003-05-01

    Single Image Random Dot Stereograms (SIRDS) are an attractive way of depicting three-dimensional objects using conventional display technology. Once trained in decoupling the eyes' convergence and focusing, autostereograms of this kind are able to convey the three-dimensional impression of a scene. We present in this work an algorithm that generates SIRDS at interactive frame rates on a conventional PC. The presented system allows rotating a 3D geometry model and observing the object from arbitrary positions in real-time. Subjective tests show that the perception of a moving or rotating 3D scene presents no problem: The gaze remains focused onto the object. In contrast to conventional SIRDS algorithms, we render multiple pixels in a single step using a texture-based approach, exploiting the parallel-processing architecture of modern graphics hardware. A vertex program determines the parallax for each vertex of the geometry model, and the graphics hardware's texture unit is used to render the dot pattern. No data has to be transferred between main memory and the graphics card for generating the autostereograms, leaving CPU capacity available for other tasks. Frame rates of 25 fps are attained at a resolution of 1024x512 pixels on a standard PC using a consumer-grade nVidia GeForce4 graphics card, demonstrating the real-time capability of the system.

  18. Emphatic, interactive volume rendering to support variance in user expertise.

    PubMed

    Stredney, Don; Ebert, David S; Svakhine, Nikolai; Bryan, Jason; Sessanna, Dennis; Wiet, Gregory J

    2005-01-01

    Various levels of representation, from abstract to schematic to realistic, have been exploited for millennia to facilitate the transfer of information from one individual to another. Learning complex information, such as that found in biomedicine, proves specifically problematic to many, and requires incremental, step-wise depictions of the information to clarify structural, functional, and procedural relationships.Emerging volume-rendering technique, such as non-photorealistic representation, coupled with advances in computational speeds, especially new graphical processing units, provide unique capabilities to explore the use of various levels of representation in interactive sessions. We have developed a system that produces images that simulate pictorial representations for both scientific and biomedical visualization. The system combines traditional and novel volume illustration techniques. We present examples from our efforts to distill representational techniques for both creative exploration and emphatic presentation for clarity. More specifically, we present our efforts to adapt these techniques for interactive simulation sessions being developed in a concurrent project for resident training in temporal bone dissection simulation. The goal of this effort is to evaluate the use of emphatic rendering to guide the user in an interactive session and to facilitate the learning of complex biomedical information, including structural, functional, and procedural information.

  19. Non-photorealistic rendering for minimally invasive procedures

    NASA Astrophysics Data System (ADS)

    Raab, Jens; Schäfer, Henry; Brost, Alexander; Stamminger, Marc; Pfister, Marcus

    2013-03-01

    Abdominal aortic aneurysms are a common disease of the aorta which are treated minimally invasive in about 33 % of the cases. Treatment is done by placing a stent graft in the aorta to prevent the aneurysm from growing. Guidance during the procedure is facilitated by fluoroscopic imaging. Unfortunately, due to low soft tissue contrast in X-ray images, the aorta itself is not visible without the application of contrast agent. To overcome this issue, advanced techniques allow to segment the aorta from pre-operative data, such as CT or MRI. Overlay images are then subsequently rendered from a mesh representation of the segmentation and fused to the live fluoroscopic images with the aim of improving the visibility of the aorta during the procedure. The current overlay images typically use forward projections of the mesh representation. This fusion technique shows deficiencies in both the 3-D information of the overlay and the visibility of the fluoroscopic image underneath. We present a novel approach to improve the visualization of the overlay images using non-photorealistic rendering techniques. Our method preserves the visibility of the devices in the fluoroscopic images while, at the same time, providing 3-D information of the fused volume. The evaluation by clinical experts shows that our method is preferred over current state-of-the-art overlay techniques. We compared three visualization techniques to the standard visualization. Our silhouette approach was chosen by clinical experts with 67 %, clearly showing the superiority of our new approach.

  20. Sparse PDF Volumes for Consistent Multi-Resolution Volume Rendering

    PubMed Central

    Sicat, Ronell; Krüger, Jens; Möller, Torsten; Hadwiger, Markus

    2015-01-01

    This paper presents a new multi-resolution volume representation called sparse pdf volumes, which enables consistent multi-resolution volume rendering based on probability density functions (pdfs) of voxel neighborhoods. These pdfs are defined in the 4D domain jointly comprising the 3D volume and its 1D intensity range. Crucially, the computation of sparse pdf volumes exploits data coherence in 4D, resulting in a sparse representation with surprisingly low storage requirements. At run time, we dynamically apply transfer functions to the pdfs using simple and fast convolutions. Whereas standard low-pass filtering and down-sampling incur visible differences between resolution levels, the use of pdfs facilitates consistent results independent of the resolution level used. We describe the efficient out-of-core computation of large-scale sparse pdf volumes, using a novel iterative simplification procedure of a mixture of 4D Gaussians. Finally, our data structure is optimized to facilitate interactive multi-resolution volume rendering on GPUs. PMID:26146475

  1. Color Me Understood.

    ERIC Educational Resources Information Center

    Harris, Judy J.

    2000-01-01

    Describes the "color system" as a way of grouping children into different personality types based on a certain color: orange, blue, green, and gold. Lists stress producers for specific color people. Asserts that, through making groups of different colors, children begin to see the various specialties others can bring to the group and learn to…

  2. Color identification testing device

    NASA Technical Reports Server (NTRS)

    Brawner, E. L.; Martin, R.; Pate, W.

    1970-01-01

    Testing device, which determines ability of a technician to identify color-coded electric wires, is superior to standard color blindness tests. It tests speed of wire selection, detects partial color blindness, allows rapid testing, and may be administered by a color blind person.

  3. Color: An Unsuspected Influence.

    ERIC Educational Resources Information Center

    Scargall, Hollie

    1999-01-01

    Discusses the appropriate use of colors in school libraries. Highlights include how colors affect students' learning and behavior; influences on users' moods; users' ages; the use of colors to bring out the best physical attributes; and the use of color for floor coverings, window treatments, furnishings, and accessories. (LRW)

  4. Appearance can be deceiving: using appearance models in color imaging

    NASA Astrophysics Data System (ADS)

    Johnson, Garrett M.

    2007-01-01

    As color imaging has evolved through the years, our toolset for understanding has similarly evolved. Research in color difference equations and uniform color spaces spawned tools such as CIELAB, which has had tremendous success over the years. Research on chromatic adaptation and other appearance phenomena then extended CIELAB to form the basis of color appearance models, such as CIECAM02. Color difference equations such as CIEDE2000 evolved to reconcile weaknesses in areas of the CIELAB space. Similarly, models such as S-CIELAB were developed to predict more spatially complex color difference calculations between images. Research in all of these fields is still going strong and there seems to be a trend towards unification of some of the tools, such as calculating color differences in a color appearance space. Along such lines, image appearance models have been developed that attempt to combine all of the above models and metric into one common framework. The goal is to allow the color imaging research to pick and choose the appropriate modeling toolset for their needs. Along these lines, the iCAM image appearance model framework was developed to study a variety of color imaging problems. These include image difference and image quality evaluations as well gamut mapping and high-dynamic range (HDR) rendering. It is important to stress that iCAM was not designed to be a complete color imaging solution, but rather a starting point for unifying models of color appearance, color difference, and spatial vision. As such the choice of model components is highly dependent on the problem being addressed. For example, with CIELAB it clearly evident that it is not necessary to use the associated color difference equations to have great success as a deviceindependent color space. Likewise, it may not be necessary to use the spatial filtering components of an image appearance model when performing image rendering. This paper attempts to shed some light on some of the

  5. Semi-parametric color reproduction method for optical see-through head-mounted displays.

    PubMed

    Itoh, Yuta; Dzitsiuk, Maksym; Amano, Toshiyuki; Klinker, Gudrun

    2015-11-01

    The fundamental issues in Augmented Reality (AR) are on how to naturally mediate the reality with virtual content as seen by users. In AR applications with Optical See-Through Head-Mounted Displays (OST-HMD), the issues often raise the problem of rendering color on the OST-HMD consistently to input colors. However, due to various display constraints and eye properties, it is still a challenging task to indistinguishably reproduce the colors on OST-HMDs. An approach to solve this problem is to pre-process the input color so that a user perceives the output color on the display to be the same as the input. We propose a color calibration method for OST-HMDs. We start from modeling the physical optics in the rendering and perception process between the HMD and the eye. We treat the color distortion as a semi-parametric model which separates the non-linear color distortion and the linear color shift. We demonstrate that calibrated images regain their original appearance on two OST-HMD setups with both synthetic and real datasets. Furthermore, we analyze the limitations of the proposed method and remaining problems of the color reproduction in OST-HMDs. We then discuss how to realize more practical color reproduction methods for future HMD-eye system.

  6. Is "Σ" purple or green? Bistable grapheme-color synesthesia induced by ambiguous characters.

    PubMed

    Kim, Suhkyung; Blake, Randolph; Kim, Chai-Youn

    2013-09-01

    People with grapheme-color synesthesia perceive specific colors when viewing different letters or numbers. Previous studies have suggested that synesthetic color experience can be bistable when induced by an ambiguous character. However, the exact relationship between processes underlying the identity of an alphanumeric character and the experience of the induced synesthetic color has not been examined. In the present study, we explored this by focusing on the temporal relation of inducer identification and color emergence using inducers whose identity could be rendered ambiguous upon rotation of the characters. Specifically, achromatic alphabetic letters (W/M) and digits (6/9) were presented at varying angles to 9 grapheme-color synesthetes. Results showed that grapheme identification and synesthetically perceived grapheme color covary with the orientation of the test stimulus and that synesthetes were slower naming the experienced color than identifying the character, particularly at intermediate angles where ambiguity was greatest.

  7. 9 CFR 314.5 - Inedible rendered fats prepared at official establishments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Inedible rendered fats prepared at... PRODUCTS AT OFFICIAL ESTABLISHMENTS § 314.5 Inedible rendered fats prepared at official establishments. Except as provided in § 325.11(b) of this subchapter, rendered animal fat derived from condemned or...

  8. 9 CFR 319.703 - Rendered animal fat or mixture thereof.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Rendered animal fat or mixture thereof... INSPECTION AND CERTIFICATION DEFINITIONS AND STANDARDS OF IDENTITY OR COMPOSITION Fats, Oils, Shortenings § 319.703 Rendered animal fat or mixture thereof. “Rendered Animal Fat,” or any mixture of...

  9. 9 CFR 319.703 - Rendered animal fat or mixture thereof.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Rendered animal fat or mixture thereof... INSPECTION AND CERTIFICATION DEFINITIONS AND STANDARDS OF IDENTITY OR COMPOSITION Fats, Oils, Shortenings § 319.703 Rendered animal fat or mixture thereof. “Rendered Animal Fat,” or any mixture of...

  10. 9 CFR 319.703 - Rendered animal fat or mixture thereof.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Rendered animal fat or mixture thereof... INSPECTION AND CERTIFICATION DEFINITIONS AND STANDARDS OF IDENTITY OR COMPOSITION Fats, Oils, Shortenings § 319.703 Rendered animal fat or mixture thereof. “Rendered Animal Fat,” or any mixture of...

  11. 9 CFR 314.5 - Inedible rendered fats prepared at official establishments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Inedible rendered fats prepared at... PRODUCTS AT OFFICIAL ESTABLISHMENTS § 314.5 Inedible rendered fats prepared at official establishments. Except as provided in § 325.11(b) of this subchapter, rendered animal fat derived from condemned or...

  12. 9 CFR 314.5 - Inedible rendered fats prepared at official establishments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Inedible rendered fats prepared at... PRODUCTS AT OFFICIAL ESTABLISHMENTS § 314.5 Inedible rendered fats prepared at official establishments. Except as provided in § 325.11(b) of this subchapter, rendered animal fat derived from condemned or...

  13. 9 CFR 319.703 - Rendered animal fat or mixture thereof.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Rendered animal fat or mixture thereof... INSPECTION AND CERTIFICATION DEFINITIONS AND STANDARDS OF IDENTITY OR COMPOSITION Fats, Oils, Shortenings § 319.703 Rendered animal fat or mixture thereof. “Rendered Animal Fat,” or any mixture of...

  14. 9 CFR 314.5 - Inedible rendered fats prepared at official establishments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Inedible rendered fats prepared at... PRODUCTS AT OFFICIAL ESTABLISHMENTS § 314.5 Inedible rendered fats prepared at official establishments. Except as provided in § 325.11(b) of this subchapter, rendered animal fat derived from condemned or...

  15. 9 CFR 314.5 - Inedible rendered fats prepared at official establishments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Inedible rendered fats prepared at... PRODUCTS AT OFFICIAL ESTABLISHMENTS § 314.5 Inedible rendered fats prepared at official establishments. Except as provided in § 325.11(b) of this subchapter, rendered animal fat derived from condemned or...

  16. Color control of a lighting system using RGBW LEDs

    NASA Astrophysics Data System (ADS)

    Tanaka, Midori; Horiuchi, Takahiko; Tominaga, Shoji

    2011-01-01

    A lighting system is proposed to render objects under a variety of colored illumination. The proposed system is constructed with a LED unit, white diffusion filters, dimmers, and a personal computer as a controller. The LED unit is composed of four kinds of color LED lamps which are 12 red (R), 14 green (G), 12 blue (B) and 10 white (W) colors. The LED lamps have a linear input-output relationship and a larger color gamut than Adobe RGB. Since the lighting system has an independent white light source, white illumination can be produced using the white light source and a mixture of RGB primary sources. Therefore, to determine illumination color we have to solve a mapping problem from 3D color space to 4D space of RGBW digital values. This paper proposes an effective algorithm for determining the digital control signals of the RGBW lights, so that colored light is generated with arbitrary (x, y) chromaticity and luminance value Y. The performance of proposed method is examined in an experiment, where the accuracy of the colored light is evaluated with regard to the CIE color difference.

  17. Full-Color Biomimetic Photonic Materials with Iridescent and Non-Iridescent Structural Colors

    NASA Astrophysics Data System (ADS)

    Kawamura, Ayaka; Kohri, Michinari; Morimoto, Gen; Nannichi, Yuri; Taniguchi, Tatsuo; Kishikawa, Keiki

    2016-09-01

    The beautiful structural colors in bird feathers are some of the brightest colors in nature, and some of these colors are created by arrays of melanin granules that act as both structural colors and scattering absorbers. Inspired by the color of bird feathers, high-visibility structural colors have been created by altering four variables: size, blackness, refractive index, and arrangement of the nano-elements. To control these four variables, we developed a facile method for the preparation of biomimetic core-shell particles with melanin-like polydopamine (PDA) shell layers. The size of the core-shell particles was controlled by adjusting the core polystyrene (PSt) particles’ diameter and the PDA shell thicknesses. The blackness and refractive index of the colloidal particles could be adjusted by controlling the thickness of the PDA shell. The arrangement of the particles was controlled by adjusting the surface roughness of the core-shell particles. This method enabled the production of both iridescent and non-iridescent structural colors from only one component. This simple and novel process of using core-shell particles containing PDA shell layers can be used in basic research on structural colors in nature and their practical applications.

  18. Full-Color Biomimetic Photonic Materials with Iridescent and Non-Iridescent Structural Colors

    PubMed Central

    Kawamura, Ayaka; Kohri, Michinari; Morimoto, Gen; Nannichi, Yuri; Taniguchi, Tatsuo; Kishikawa, Keiki

    2016-01-01

    The beautiful structural colors in bird feathers are some of the brightest colors in nature, and some of these colors are created by arrays of melanin granules that act as both structural colors and scattering absorbers. Inspired by the color of bird feathers, high-visibility structural colors have been created by altering four variables: size, blackness, refractive index, and arrangement of the nano-elements. To control these four variables, we developed a facile method for the preparation of biomimetic core-shell particles with melanin-like polydopamine (PDA) shell layers. The size of the core-shell particles was controlled by adjusting the core polystyrene (PSt) particles’ diameter and the PDA shell thicknesses. The blackness and refractive index of the colloidal particles could be adjusted by controlling the thickness of the PDA shell. The arrangement of the particles was controlled by adjusting the surface roughness of the core-shell particles. This method enabled the production of both iridescent and non-iridescent structural colors from only one component. This simple and novel process of using core-shell particles containing PDA shell layers can be used in basic research on structural colors in nature and their practical applications. PMID:27658446

  19. Grid fill algorithm for vector graphics render on mobile devices

    NASA Astrophysics Data System (ADS)

    Zhang, Jixian; Yue, Kun; Yuan, Guowu; Zhang, Binbin

    2015-12-01

    The performance of vector graphics render has always been one of the key elements in mobile devices and the most important step to improve the performance is to enhance the efficiency of polygon fill algorithms. In this paper, we proposed a new and more efficient polygon fill algorithm based on the scan line algorithm and Grid Fill Algorithm (GFA). First, we elaborated the GFA through solid fill. Second, we described the techniques for implementing antialiasing and self-intersection polygon fill with GFA. Then, we discussed the implementation of GFA based on the gradient fill. Generally, compared to other fill algorithms, GFA has better performance and achieves faster fill speed, which is specifically consistent with the inherent characteristics of mobile devices. Experimental results show that better fill effects can be achieved by using GFA.

  20. The Use of Color as a Third Dimension on Maps

    NASA Astrophysics Data System (ADS)

    Cid, X.; Lopez, R.; Lazarus, S.

    2007-12-01

    As experts, we are trained to understand color schemes used in visualizations in our respective scientific fields. As experts we also forget how complicated graphics can be when viewed for the first time. Previous studies have shown that three-dimensional diagrams can produce a cognitive overload when rendered on a two-dimensional surface, so the same might apply to graphics that use color as a third dimension. This study was conducted to investigate the use of color as a third dimension. We looked at the use of color as a scale height on a basic topographic map, as well as the use of color as temperature. Fifty-four undergraduates from two different physics courses and REU programs during the spring and summer semesters in 2007 were given surveys regarding the use of color. Of these 54 students, eight students were chosen to participate in interviews designed to investigate, in more detail, the responses provided by the students in the hopes to discover where confusions occur. It was found that students have an embedded color scheme for temperatures of red representing hot and blue representing cold as a product of societal influences, which was expected, but there was no embedded color scheme when color was applied to height. We found that students did not have a preference when viewing a topographic map with different color schemes, but did prefer the color scheme of the figure that they viewed first. We observed that the students did have an embedded notion of what the topographic figure was representing, and tried to fit the color scheme shown to match their idea. During the interviews we also found that even the slightest deviations from a specific color scheme gives rise to confusion. These results, therefore, show the importance of detail consistency when using visualizations in a lecture where the population is composed of novices.

  1. Technologies Render Views of Earth for Virtual Navigation

    NASA Technical Reports Server (NTRS)

    2012-01-01

    On a December night in 1995, 159 passengers and crewmembers died when American Airlines Flight 965 flew into the side of a mountain while in route to Cali, Colombia. A key factor in the tragedy: The pilots had lost situational awareness in the dark, unfamiliar terrain. They had no idea the plane was approaching a mountain until the ground proximity warning system sounded an alarm only seconds before impact. The accident was of the kind most common at the time CFIT, or controlled flight into terrain says Trey Arthur, research aerospace engineer in the Crew Systems and Aviation Operations Branch at NASA s Langley Research Center. In situations such as bad weather, fog, or nighttime flights, pilots would rely on airspeed, altitude, and other readings to get an accurate sense of location. Miscalculations and rapidly changing conditions could contribute to a fully functioning, in-control airplane flying into the ground. To improve aviation safety by enhancing pilots situational awareness even in poor visibility, NASA began exploring the possibilities of synthetic vision creating a graphical display of the outside terrain on a screen inside the cockpit. How do you display a mountain in the cockpit? You have to have a graphics-powered computer, a terrain database you can render, and an accurate navigation solution, says Arthur. In the mid-1990s, developing GPS technology offered a means for determining an aircraft s position in space with high accuracy, Arthur explains. As the necessary technologies to enable synthetic vision emerged, NASA turned to an industry partner to develop the terrain graphical engine and database for creating the virtual rendering of the outside environment.

  2. Chronic Alcohol Exposure Renders Epithelial Cells Vulnerable to Bacterial Infection

    PubMed Central

    Wood, Stephen; Pithadia, Ravi; Rehman, Tooba; Zhang, Lijuan; Plichta, Jennifer; Radek, Katherine A.; Forsyth, Christopher; Keshavarzian, Ali; Shafikhani, Sasha H.

    2013-01-01

    Despite two centuries of reports linking alcohol consumption with enhanced susceptibility to bacterial infections and in particular gut-derived bacteria, there have been no studies or model systems to assess the impact of long-term alcohol exposure on the ability of the epithelial barrier to withstand bacterial infection. It is well established that acute alcohol exposure leads to reduction in tight and adherens junctions, which in turn leads to increases in epithelial cellular permeability to bacterial products, leading to endotoxemia and a variety of deleterious effects in both rodents and human. We hypothesized that reduced fortification at junctional structures should also reduce the epithelial barrier’s capacity to maintain its integrity in the face of bacterial challenge thus rendering epithelial cells more vulnerable to infection. In this study, we established a cell-culture based model system for long-term alcohol exposure to assess the impact of chronic alcohol exposure on the ability of Caco-2 intestinal epithelial cells to withstand infection when facing pathogenic bacteria under the intact or wounded conditions. We report that daily treatment with 0.2% ethanol for two months rendered Caco-2 cells far more susceptible to wound damage and cytotoxicity caused by most but not all bacterial pathogens tested in our studies. Consistent with acute alcohol exposure, long-term ethanol exposure also adversely impacted tight junction structures, but in contrast, it did not affect the adherens junction. Finally, alcohol-treated cells partially regained their ability to withstand infection when ethanol treatment was ceased for two weeks, indicating that alcohol’s deleterious effects on cells may be reversible. PMID:23358457

  3. Chronic alcohol exposure renders epithelial cells vulnerable to bacterial infection.

    PubMed

    Wood, Stephen; Pithadia, Ravi; Rehman, Tooba; Zhang, Lijuan; Plichta, Jennifer; Radek, Katherine A; Forsyth, Christopher; Keshavarzian, Ali; Shafikhani, Sasha H

    2013-01-01

    Despite two centuries of reports linking alcohol consumption with enhanced susceptibility to bacterial infections and in particular gut-derived bacteria, there have been no studies or model systems to assess the impact of long-term alcohol exposure on the ability of the epithelial barrier to withstand bacterial infection. It is well established that acute alcohol exposure leads to reduction in tight and adherens junctions, which in turn leads to increases in epithelial cellular permeability to bacterial products, leading to endotoxemia and a variety of deleterious effects in both rodents and human. We hypothesized that reduced fortification at junctional structures should also reduce the epithelial barrier's capacity to maintain its integrity in the face of bacterial challenge thus rendering epithelial cells more vulnerable to infection. In this study, we established a cell-culture based model system for long-term alcohol exposure to assess the impact of chronic alcohol exposure on the ability of Caco-2 intestinal epithelial cells to withstand infection when facing pathogenic bacteria under the intact or wounded conditions. We report that daily treatment with 0.2% ethanol for two months rendered Caco-2 cells far more susceptible to wound damage and cytotoxicity caused by most but not all bacterial pathogens tested in our studies. Consistent with acute alcohol exposure, long-term ethanol exposure also adversely impacted tight junction structures, but in contrast, it did not affect the adherens junction. Finally, alcohol-treated cells partially regained their ability to withstand infection when ethanol treatment was ceased for two weeks, indicating that alcohol's deleterious effects on cells may be reversible. PMID:23358457

  4. Discrete Modal Decomposition for surface appearance modelling and rendering

    NASA Astrophysics Data System (ADS)

    Pitard, Gilles; Le Goïc, Gaëtan; Favrelière, Hugues; Samper, Serge; Desage, Simon-Frédéric; Pillet, Maurice

    2015-05-01

    Controlling surface appearance has become essential in the supplier/customer relationship. In this context, many industries have implemented new methods to improve the sensory inspection, particularly in terms of variability. A trend is to develop both hardware and methods for moving towards the automation of appearance inspection and analysis. If devices inspired from dimensional control solutions generally allow to identify defects far apart the expected quality of products, it do not allow to quantify finely appearance anomalies, and decide on their acceptance. To address this issue, new methods devoted to appearance modelling and rendering have been implemented, such as the Reflectance Transformation Imaging (RTI) technique. By varying the illumination positions, the RTI technique aims at enriching the classical information conveyed by images. Thus each pixel is described by a set of values rather than one value classically; each value corresponding to a specific illumination position. This set of values could be interpolated or approximated by a continuous model (function), associated to the reflectance of the pixel, generally based on a second order polynomial (namely, Polynomial Texture Mapping Technique). This paper presents a new approach to evaluate this information from RTI acquisitions. A modal projection based on dynamics (Discrete Modal Decomposition) is used to estimate surface reflectance on each measurement point. After presenting the acquisition device, an application on an industrial surface is proposed in order to validate the approach, and compare it to the more classical polynomial transformation. Results show that the proposed projection basis not only provides closer assessment of surface reflectance (modelling) but also yields to a more realistic rendering.

  5. On-the-Fly Decompression and Rendering of Multiresolution Terrain

    SciTech Connect

    Lindstrom, P; Cohen, J D

    2009-04-02

    We present a streaming geometry compression codec for multiresolution, uniformly-gridded, triangular terrain patches that supports very fast decompression. Our method is based on linear prediction and residual coding for lossless compression of the full-resolution data. As simplified patches on coarser levels in the hierarchy already incur some data loss, we optionally allow further quantization for more lossy compression. The quantization levels are adaptive on a per-patch basis, while still permitting seamless, adaptive tessellations of the terrain. Our geometry compression on such a hierarchy achieves compression ratios of 3:1 to 12:1. Our scheme is not only suitable for fast decompression on the CPU, but also for parallel decoding on the GPU with peak throughput over 2 billion triangles per second. Each terrain patch is independently decompressed on the fly from a variable-rate bitstream by a GPU geometry program with no branches or conditionals. Thus we can store the geometry compressed on the GPU, reducing storage and bandwidth requirements throughout the system. In our rendering approach, only compressed bitstreams and the decoded height values in the view-dependent 'cut' are explicitly stored on the GPU. Normal vectors are computed in a streaming fashion, and remaining geometry and texture coordinates, as well as mesh connectivity, are shared and re-used for all patches. We demonstrate and evaluate our algorithms on a small prototype system in which all compressed geometry fits in the GPU memory and decompression occurs on the fly every rendering frame without any cache maintenance.

  6. Distributed Dimensonality-Based Rendering of LIDAR Point Clouds

    NASA Astrophysics Data System (ADS)

    Brédif, M.; Vallet, B.; Ferrand, B.

    2015-08-01

    Mobile Mapping Systems (MMS) are now commonly acquiring lidar scans of urban environments for an increasing number of applications such as 3D reconstruction and mapping, urban planning, urban furniture monitoring, practicability assessment for persons with reduced mobility (PRM)... MMS acquisitions are usually huge enough to incur a usability bottleneck for the increasing number of non-expert user that are not trained to process and visualize these huge datasets through specific softwares. A vast majority of their current need is for a simple 2D visualization that is both legible on screen and printable on a static 2D medium, while still conveying the understanding of the 3D scene and minimizing the disturbance of the lidar acquisition geometry (such as lidar shadows). The users that motivated this research are, by law, bound to precisely georeference underground networks for which they currently have schematics with no or poor absolute georeferencing. A solution that may fit their needs is thus a 2D visualization of the MMS dataset that they could easily interpret and on which they could accurately match features with their user datasets they would like to georeference. Our main contribution is two-fold. First, we propose a 3D point cloud stylization for 2D static visualization that leverages a Principal Component Analysis (PCA)-like local geometry analysis. By skipping the usual and error-prone estimation of a ground elevation, this rendering is thus robust to non-flat areas and has no hard-to-tune parameters such as height thresholds. Second, we implemented the corresponding rendering pipeline so that it can scale up to arbitrary large datasets by leveraging the Spark framework and its Resilient Distributed Dataset (RDD) and Dataframe abstractions.

  7. Biotechnological production of colorants.

    PubMed

    de Boer, Lex

    2014-01-01

    The color of food and drinks is important, as it is associated with freshness and taste. Despite that natural colorants are more expensive to produce, less stable to heat and light, and less consistent in color range, natural colorants have been gaining market share in recent years. The background is that artificial colorants are often associated with negative health aspects. Considerable progress has been made towards the fermentative production of some colorants. Because colorant biosynthesis is under close metabolic control, extensive strain and process development are needed in order to establish an economical production process. Another approach is the synthesis of colors by means of biotransformation of adequate precursors. Algae represent a promising group of microorganisms that have shown a high potential for the production of different colorants, and dedicated fermentation and downstream technologies have been developed. This chapter reviews the available information with respect to these approaches. PMID:24037500

  8. Spirit Beholds Bumpy Boulder (False Color)

    NASA Technical Reports Server (NTRS)

    2006-01-01

    As NASA's Mars Exploration Rover Spirit began collecting images for a 360-degree panorama of new terrain, the rover captured this view of a dark boulder with an interesting surface texture. The boulder sits about 40 centimeters (16 inches) tall on Martian sand about 5 meters (16 feet) away from Spirit. It is one of many dark, volcanic rock fragments -- many pocked with rounded holes called vesicles -- littering the slope of 'Low Ridge.' The rock surface facing the rover is similar in appearance to the surface texture on the outside of lava flows on Earth.

    Spirit took this false-color image with the panoramic camera on the rover's 810th sol, or Martian day, of exploring Mars (April 13, 2006). This image is a false-color rendering using camera's 753-nanometer, 535-nanometer, and 432-nanometer filters.

  9. Radiation coloration resistant glass

    DOEpatents

    Tomozawa, M.; Watson, E.B.; Acocella, J.

    1986-11-04

    A radiation coloration resistant glass is disclosed which is used in a radiation environment sufficient to cause coloration in most forms of glass. The coloration resistant glass includes higher proportions by weight of water and has been found to be extremely resistant to color change when exposed to such radiation levels. The coloration resistant glass is free of cerium oxide and has more than about 0.5% by weight water content. Even when exposed to gamma radiation of more than 10[sup 7] rad, the coloration resistant glass does not lose transparency. 3 figs.

  10. Radiation coloration resistant glass

    DOEpatents

    Tomozawa, Minoru; Watson, E. Bruce; Acocella, John

    1986-01-01

    A radiation coloration resistant glass is disclosed which is used in a radiation environment sufficient to cause coloration in most forms of glass. The coloration resistant glass includes higher proportions by weight of water and has been found to be extremely resistant to color change when exposed to such radiation levels. The coloration resistant glass is free of cerium oxide and has more than about 0.5% by weight water content. Even when exposed to gamma radiation of more than 10.sup.7 rad, the coloration resistant glass does not lose transparency.

  11. Preferred skin color enhancement for photographic color reproduction

    NASA Astrophysics Data System (ADS)

    Zeng, Huanzhao; Luo, Ronnier

    2011-01-01

    Skin tones are the most important colors among the memory color category. Reproducing skin colors pleasingly is an important factor in photographic color reproduction. Moving skin colors toward their preferred skin color center improves the color preference of skin color reproduction. Several methods to morph skin colors to a smaller preferred skin color region has been reported in the past. In this paper, a new approach is proposed to further improve the result of skin color enhancement. An ellipsoid skin color model is applied to compute skin color probabilities for skin color detection and to determine a weight for skin color adjustment. Preferred skin color centers determined through psychophysical experiments were applied for color adjustment. Preferred skin color centers for dark, medium, and light skin colors are applied to adjust skin colors differently. Skin colors are morphed toward their preferred color centers. A special processing is applied to avoid contrast loss in highlight. A 3-D interpolation method is applied to fix a potential contouring problem and to improve color processing efficiency. An psychophysical experiment validates that the method of preferred skin color enhancement effectively identifies skin colors, improves the skin color preference, and does not objectionably affect preferred skin colors in original images.

  12. INDEXING MECHANISM

    DOEpatents

    Kock, L.J.

    1959-09-22

    A device is presented for loading and unloading fuel elements containing material fissionable by neutrons of thermal energy. The device comprises a combination of mechanical features Including a base, a lever pivotally attached to the base, an Indexing plate on the base parallel to the plane of lever rotation and having a plurality of apertures, the apertures being disposed In rows, each aperture having a keyway, an Index pin movably disposed to the plane of lever rotation and having a plurality of apertures, the apertures being disposed in rows, each aperture having a keyway, an index pin movably disposed on the lever normal to the plane rotation, a key on the pin, a sleeve on the lever spaced from and parallel to the index pin, a pair of pulleys and a cable disposed between them, an open collar rotatably attached to the sleeve and linked to one of the pulleys, a pin extending from the collar, and a bearing movably mounted in the sleeve and having at least two longitudinal grooves in the outside surface.

  13. A Parallel Pipelined Renderer for the Time-Varying Volume Data

    NASA Technical Reports Server (NTRS)

    Chiueh, Tzi-Cker; Ma, Kwan-Liu

    1997-01-01

    This paper presents a strategy for efficiently rendering time-varying volume data sets on a distributed-memory parallel computer. Time-varying volume data take large storage space and visualizing them requires reading large files continuously or periodically throughout the course of the visualization process. Instead of using all the processors to collectively render one volume at a time, a pipelined rendering process is formed by partitioning processors into groups to render multiple volumes concurrently. In this way, the overall rendering time may be greatly reduced because the pipelined rendering tasks are overlapped with the I/O required to load each volume into a group of processors; moreover, parallelization overhead may be reduced as a result of partitioning the processors. We modify an existing parallel volume renderer to exploit various levels of rendering parallelism and to study how the partitioning of processors may lead to optimal rendering performance. Two factors which are important to the overall execution time are re-source utilization efficiency and pipeline startup latency. The optimal partitioning configuration is the one that balances these two factors. Tests on Intel Paragon computers show that in general optimal partitionings do exist for a given rendering task and result in 40-50% saving in overall rendering time.

  14. Color and Streptomycetes1

    PubMed Central

    Pridham, Thomas G.

    1965-01-01

    A report summarizing the results of an international workshop on determination of color of streptomycetes is presented. The results suggest that the color systems which seem most practically appealing and effective to specialists on actinomycetes are those embracing a limited number of color names and groups. The broad groupings allow placement of isolates into reasonably well-defined categories based on color of aerial mycelium. Attempts to expand such systems (more color groups) lead to difficulties. It is common knowledge that many, if not all, of the individual groups would in these broad systems contain strains that differ in many other respects, e.g., spore-wall ornamentation, color of vegetative (substratal) mycelium, morphology of chains of spores, and numerous physiological criteria. Also, cultures of intermediate color can be found, which makes placement difficult. As it now stands, color as a criterion for characterization of streptomycetes and streptoverticillia is in questionable status. Although much useful color information can be obtained by an individual, the application of this information to that in the literature or its use in communication with other individuals leaves much to be desired. More objective methods of color determination are needed. At present, the most effective method that could be used internationally is the color-wheel system of Tresner and Backus. Furthermore, the significance of color in speciation of these organisms is an open question. Obviously, more critical work on the color problem is needed. PMID:14264847

  15. Why color synesthesia involves more than color.

    PubMed

    Eagleman, David M; Goodale, Melvyn A

    2009-07-01

    Synesthesia is a perceptual phenomenon in which stimuli can trigger experiences in non-stimulated sensory dimensions. The literature has focused on forms of synesthesia in which stimuli (e.g. music, touch or numbers) trigger experiences of color. Generally missing, however, is the observation that synesthetic colors are often accompanied by the experience of other surface properties such as texture (e.g. a visual experience of linen, metal, marble, velvet, etc). Current frameworks for synesthesia focus only upon the involvement of brain regions such as the V4 color complex. Here, we propose an expanded framework that includes brain regions involved in the encoding of material properties - specifically, larger regions of the medial ventral stream. The overlap of visual texture and color processing within ventral regions might explain why many experiences of synesthesia extend beyond color to other material properties.

  16. Rendering Future Vegetation Change across Large Regions of the US

    NASA Astrophysics Data System (ADS)

    Sant'Anna Dias, Felipe; Gu, Yuting; Agarwalla, Yashika; Cheng, Yiwei; Patil, Sopan; Stieglitz, Marc; Turk, Greg

    2015-04-01

    We use two Machine Learning techniques, Decision Trees (DT) and Neural Networks (NN), to provide classified images and photorealistic renderings of future vegetation cover at three large regions in the US. The training data used to generate current vegetation cover include Landsat surface reflectance images, USGS Land Cover maps, 50 years of mean annual temperature and precipitation for the period 1950 - 2000, elevation, aspect and slope data. Present vegetation cover was generated on a 100m grid. Future vegetation cover for the period 2061- 2080 was predicted using the 1 km resolution bias corrected data from the NASA Goddard Institute for Space Studies Global Climate Model E simulation. The three test regions encompass a wide range of climatic gradients, topographic variation, and vegetation cover. The central Oregon site covers 19,182 square km and includes the Ochoco and Malheur National Forest. Vegetation cover is 50% evergreen forest and 50% shrubs and scrubland. The northwest Washington site covers 14,182 square km. Vegetation cover is 60% evergreen forest, 14% scrubs, 7% grassland, and 7% barren land. The remainder of the area includes deciduous forest, perennial snow cover, and wetlands. The third site, the Jemez mountain region of north central New Mexico, covers 5,500 square km. Vegetation cover is 47% evergreen forest, 31% shrubs, 13% grasses, and 3% deciduous forest. The remainder of the area includes developed and cultivated areas and wetlands. Using the above mentioned data sets we first trained our DT and NN models to reproduce current vegetation. The land cover classified images were compared directly to the USGS land cover data. The photorealistic generated vegetation images were compared directly to the remotely sensed surface reflectance maps. For all three sites, similarity between generated and observed vegetation cover was quite remarkable. The three trained models were then used to explore what the equilibrium vegetation would look like for

  17. Light, Color, and Mirrors.

    ERIC Educational Resources Information Center

    Tiburzi, Brian; Tamborino, Laurie; Parker, Gordon A.

    2000-01-01

    Describes an exercise in which students can use flashlights, mirrors, and colored paper to discover scientific principles regarding optics. Addresses the concepts of angles of incidence and reflection, colored vs. white light, and mirror images. (WRM)

  18. Developments in Color Micrographics.

    ERIC Educational Resources Information Center

    Hourdajian, Ara

    1983-01-01

    Summarizes recent progress in color micrographics, which has centered about the corporate development of new microfilms whose capacities for reproducing and sustaining color image far exceed those of their predecessors. (Author/EJS)

  19. Color vision: retinal blues.

    PubMed

    Johnston, Jamie; Esposti, Federico; Lagnado, Leon

    2012-08-21

    Two complementary studies have resolved the circuitry underlying green-blue color discrimination in the retina. A blue-sensitive interneuron provides the inhibitory signal required for computing green-blue color opponency.

  20. Color photography of Jupiter

    NASA Technical Reports Server (NTRS)

    Larson, S. M.; Fountain, J. W.; Mintor, R. B.

    1973-01-01

    Selected color photographs of Jupiter taken with the 154-cm Catalina reflector from October 1965 to September 1973 are presented. Eight oppositions are covered showing the developments in cloud belt structure and color distribution of the Jovian atmosphere.

  1. The Trouble with Color.

    ERIC Educational Resources Information Center

    Merchant, David

    1999-01-01

    Discusses problems with color quality in Web sites. Topics include differences in monitor settings, including contrast; amount of video RAM; user preference settings; browser-safe colors; cross-platform readability; and gamma values. (LRW)

  2. PV modules, using color solar cells, designed for building

    SciTech Connect

    Ishikawa, N.; Yamashita, H.; Goda, S.

    1994-12-31

    The designs and structures of a photovoltaic module to be installed in a curtain wall were examined with the object of sharply reducing PV power generation costs. As for the design, solar cells of different colors were produced and an opinion survey of designers and other construction-related persons was conducted. Renderings based on color solar cells were prepared using computer graphics. In general, the output of cells decreases for colors other than shades of dark blue. However, there is a good possibility that greater importance will be put on design, including color and surface condition, than on output. In this case, the market share may expand and as a result, the cost may drop. As for the structure, various materials that can be used for a building-material-integrated-module were investigated and methods to install PV modules into building materials were examined. Moreover, experimental module samples fitted with stainless steel sheets and aluminum-sash frames were made.

  3. Color image reproduction: the evolution from print to multimedia

    NASA Astrophysics Data System (ADS)

    MacDonald, Lindsay W.

    1997-02-01

    The electronic pre-press industry has undergone a very rapid evolution over the past decade, driven by the accelerating performance of desktop computers and affordable application software for image manipulation, page layout and color separation. These have been supported by the steady development of colo scanners, digital cameras, proof printers, RIPs and image setters, all of which make the process of reproducing color images in print easier than ever before. But is color print itself in decline as a medium? New channels of delivery for digital color images include CD-ROM, wideband networks and the Internet, with soft-copy screen display competing with hard-copy print for applications ranging from corporate brochures to home shopping. Present indications are that the most enduring of the graphic arts skills in the new multimedia world will be image rendering and production control rather than those related to photographic film and ink on paper.

  4. Dissipative rendering and neural network control system design

    NASA Technical Reports Server (NTRS)

    Gonzalez, Oscar R.

    1995-01-01

    Model-based control system designs are limited by the accuracy of the models of the plant, plant uncertainty, and exogenous signals. Although better models can be obtained with system identification, the models and control designs still have limitations. One approach to reduce the dependency on particular models is to design a set of compensators that will guarantee robust stability to a set of plants. Optimization over the compensator parameters can then be used to get the desired performance. Conservativeness of this approach can be reduced by integrating fundamental properties of the plant models. This is the approach of dissipative control design. Dissipative control designs are based on several variations of the Passivity Theorem, which have been proven for nonlinear/linear and continuous-time/discrete-time systems. These theorems depend not on a specific model of a plant, but on its general dissipative properties. Dissipative control design has found wide applicability in flexible space structures and robotic systems that can be configured to be dissipative. Currently, there is ongoing research to improve the performance of dissipative control designs. For aircraft systems that are not dissipative active control may be used to make them dissipative and then a dissipative control design technique can be used. It is also possible that rendering a system dissipative and dissipative control design may be combined into one step. Furthermore, the transformation of a non-dissipative system to dissipative can be done robustly. One sequential design procedure for finite dimensional linear time-invariant systems has been developed. For nonlinear plants that cannot be controlled adequately with a single linear controller, model-based techniques have additional problems. Nonlinear system identification is still a research topic. Lacking analytical models for model-based design, artificial neural network algorithms have recently received considerable attention. Using

  5. Sixty-five thousand shades of gray: importance of color in surgical pathology diagnoses.

    PubMed

    Campbell, W Scott; Talmon, Geoffrey A; Foster, Kirk W; Lele, Subodh M; Kozel, Jessica A; West, William W

    2015-12-01

    Digital whole slide imaging (WSI) is a diagnostic modality that has gained acceptance as a tool for use in some areas of surgical pathology such as remote consultations. Accurate control of color representation of digitally rendered images of histologic sections is considered an important parameter of WSI. Currently, professional societies, physicians, and other stakeholders are in the process of establishing clinical guidelines outlining the use of these devices, which include color integrity and color calibration of scanners and viewing devices. Although color is a component of surgical pathology diagnoses, it was posited that pathologists could accurately diagnose surgical specimens without color. To test this hypothesis, 5 pathologists were presented breast biopsy specimens from 20 patients consisting of 22 separate tissue specimens and WSI of 158 hematoxylin and eosin-stained slides imaged at ×20. No special stains were included. The pathologists reviewed each case using a 16-bit grayscale monitor and rendered a diagnosis for each case. Diagnoses were compared to the original light microscopy diagnoses and scored for concordance. A 92.7% concordance was observed. Discordant diagnoses represented well-known areas of diagnostic disagreement in breast pathology as well as known limitations of WSI. The research demonstrated that surgical pathologists did not rely primarily on color to render accurate diagnoses of breast biopsy cases but rather used architectural features of tissue and cellular morphology to reach a diagnostic conclusion. This research did not suggest that color is an unimportant factor in pathology diagnosis, but its importance may be overstated.

  6. Color science demonstration kit from open source hardware and software

    NASA Astrophysics Data System (ADS)

    Zollers, Michael W.

    2014-09-01

    Color science is perhaps the most universally tangible discipline within the optical sciences for people of all ages. Excepting a small and relatively well-understood minority, we can see that the world around us consists of a multitude of colors; yet, describing the "what", "why", and "how" of these colors is not an easy task, especially without some sort of equally colorful visual aids. While static displays (e.g., poster boards, etc.) serve their purpose, there is a growing trend, aided by the recent permeation of small interactive devices into our society, for interactive and immersive learning. However, for the uninitiated, designing software and hardware for this purpose may not be within the purview of all optical scientists and engineers. Enter open source. Open source "anything" are those tools and designs -- hardware or software -- that are available and free to use, often without any restrictive licensing. Open source software may be familiar to some, but the open source hardware movement is relatively new. These are electronic circuit board designs that are provided for free and can be implemented in physical hardware by anyone. This movement has led to the availability of some relatively inexpensive, but quite capable, computing power for the creation of small devices. This paper will showcase the design and implementation of the software and hardware that was used to create an interactive demonstration kit for color. Its purpose is to introduce and demonstrate the concepts of color spectra, additive color, color rendering, and metamers.

  7. Color filter array demosaicing: an adaptive progressive interpolation based on the edge type

    NASA Astrophysics Data System (ADS)

    Dong, Qiqi; Liu, Zhaohui

    2015-10-01

    Color filter array (CFA) is one of the key points for single-sensor digital cameras to produce color images. Bayer CFA is the most commonly used pattern. In this array structure, the sampling frequency of green is two times of red or blue, which is consistent with the sensitivity of human eyes to colors. However, each sensor pixel only samples one of three primary color values. To render a full-color image, an interpolation process, commonly referred to CFA demosaicing, is required to estimate the other two missing color values at each pixel. In this paper, we explore an adaptive progressive interpolation based on the edge type algorithm. The proposed demosaicing method consists of two successive steps: an interpolation step that estimates missing color values according to various edges and a post-processing step by iterative interpolation.

  8. Inkjet Color Printing by Interference Nanostructures.

    PubMed

    Yakovlev, Aleksandr V; Milichko, Valentin A; Vinogradov, Vladimir V; Vinogradov, Alexandr V

    2016-03-22

    Color printing technology is developing rapidly; in less than 40 years, it moved from dot matrix printers with an ink-soaked cloth ribbon to 3D printers used to make three-dimensional color objects. Nevertheless, what remained unchanged over this time is the fact that in each case, dye inks (CMYK or RGB color schemes) were exclusively used for coloring, which inevitably limits the technological possibilities and color reproduction. As a next step in printing color images and storing information, we propose the technology of producing optical nanostructures. In this paper, we report use of inkjet technology to create colored interference layers with high accuracy without the need for high-temperature fixing. This was made possible due to using titania-based colloidal ink yielding monolithic coatings with a high refractive index (2.00 ± 0.08 over the entire visible range) when naturally dried. By controlling the film thickness by using inkjet deposition, we produced images based on controlled interference and implementing color printing with one ink. The lack of dyes in the proposed method has good environmental prospects, because applied systems based on a crystalline anatase sol are nontoxic and biologically inert. The paper explains in detail the principle of producing interference images by the classical inkjet method and shows the advantages of this technique in depositing coatings with uniform thickness, which are required for large-scale interference color imaging even on unprepared polymer films. This article demonstrates the possibility of inkjet printing of nanostructures with a precision in thickness of up to 50 nm, we believe that the proposed approach will be the groundwork for developing interference color printing approach and allow to implement new methods of forming optical nano-objects by widely available techniques.

  9. Biology of Skin Color.

    ERIC Educational Resources Information Center

    Corcos, Alain

    1983-01-01

    Information from scientific journals on the biology of skin color is discussed. Major areas addressed include: (1) biology of melanin, melanocytes, and melanosomes; (2) melanosome and human diversity; (3) genetics of skin color; and (4) skin color, geography, and natural selection. (JN)

  10. Sweetpotato Color Analyses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Color is an important attribute that contributes to the appearance of a sweetpotato genotype. A consumer uses color, along with geometric attributes (e.g., gloss, luster, sheen, texture, opaqueness, shape), to subjectively evaluate the appearance of a sweetpotato root. Color can be quantified by t...

  11. Reimagining the Color Wheel

    ERIC Educational Resources Information Center

    Snyder, Jennifer

    2011-01-01

    Color wheels are a traditional project for many teachers. The author has used them in art appreciation classes for many years, but one problem she found when her pre-service art education students created colored wheels was that they were boring: simple circles, with pie-shaped pieces, which students either painted or colored in. This article…

  12. Inverse rendering of faces with a 3D morphable model.

    PubMed

    Aldrian, Oswald; Smith, William A P

    2013-05-01

    In this paper, we present a complete framework to inverse render faces with a 3D Morphable Model (3DMM). By decomposing the image formation process into geometric and photometric parts, we are able to state the problem as a multilinear system which can be solved accurately and efficiently. As we treat each contribution as independent, the objective function is convex in the parameters and a global solution is guaranteed. We start by recovering 3D shape using a novel algorithm which incorporates generalization error of the model obtained from empirical measurements. We then describe two methods to recover facial texture, diffuse lighting, specular reflectance, and camera properties from a single image. The methods make increasingly weak assumptions and can be solved in a linear fashion. We evaluate our findings on a publicly available database, where we are able to outperform an existing state-of-the-art algorithm. We demonstrate the usability of the recovered parameters in a recognition experiment conducted on the CMU-PIE database. PMID:23520253

  13. Lighting System for Visual Perception Enhancement in Volume Rendering.

    PubMed

    Wang, Lei; Kaufman, Arie E

    2013-01-01

    We introduce a lighting system that enhances the visual cues in a rendered image for the perception of 3D volumetric objects. We divide the lighting effects into global and local effects, and deploy three types of directional lights: the key light and accessory lights (fill and detail lights). The key light provides both lighting effects and carries the visual cues for the perception of local and global shapes and depth. The cues for local shapes are conveyed by gradient; those for global shapes are carried by shadows; and those for depth are provided by shadows and translucent objects. Fill lights produce global effects to increase the perceptibility. Detail lights generate local effects to improve the cues for local shapes. Our method quantifies the perception and uses an exhaustive search to set the lights. It configures accessory lights with the consideration of preserving the global impression conveyed by the key light. It ensures the feeling of smooth light movements in animations. With simplification, it achieves interactive frame rates and produces results that are visually indistinguishable from results using the nonsimplified algorithm. The major contributions of this paper are our lighting system, perception measurement and lighting design algorithm with our indistinguishable simplification.

  14. [Usefulness of volume rendering stereo-movie in neurosurgical craniotomies].

    PubMed

    Fukunaga, Tateya; Mokudai, Toshihiko; Fukuoka, Masaaki; Maeda, Tomonori; Yamamoto, Kouji; Yamanaka, Kozue; Minakuchi, Kiyomi; Miyake, Hirohisa; Moriki, Akihito; Uchida, Yasufumi

    2007-12-20

    In recent years, the advancements in MR technology combined with the development of the multi-channel coil have resulted in substantially shortened inspection times. In addition, rapid improvement in functional performance in the workstation has produced a more simplified imaging-making process. Consequently, graphical images of intra-cranial lesions can be easily created. For example, the use of three-dimensional spoiled gradient echo (3D-SPGR) volume rendering (VR) after injection of a contrast medium is applied clinically as a preoperative reference image. Recently, improvements in 3D-SPGR VR high-resolution have enabled accurate surface images of the brain to be obtained. We used stereo-imaging created by weighted maximum intensity projection (Weighted MIP) to determine the skin incision line. Furthermore, the stereo imaging technique utilizing 3D-SPGR VR was actually used in cases presented here. The techniques we report here seemed to be very useful in the pre-operative simulation of neurosurgical craniotomy.

  15. Rendering log aesthetic curves via Runge-Kutta method

    NASA Astrophysics Data System (ADS)

    Gobithaasan, R. U.; Meng, T. Y.; Piah, A. R. M.; Miura, K. T.

    2014-07-01

    Log Aesthetic Curves (LAC) are visually pleasing curves which has been developed using monotonic curvature profile. Hence, it can be easily implemented in product design environment, e.g, Rhino 3D CAD systems. LAC is generally represented in an integral form of its turning angle. Traditionally, Gaussian-Kronrod method has been used to render this curve which consumes less than one second for a given interval. Recently, Incomplete Gamma Function was proposed to represent LAC analytically which decreases the computation time up to 13 times. However, only certain value of shape parameters (denoted as α) which dictates the types of curves generated for LAC, can be used to compute LAC. In this paper, the classical Runge-Kutta (RK4) method is proposed to evaluate LAC numerically to reduce the LAC computation time for arbitrary, α. The preliminary result looks promising where the evaluation time is decreased tremendously. This paper also demonstrates the accuracy control of LAC by reducing the stepsize of RK4. The computation time and the accuracy for various α, are also illustrated in the last section of this paper.

  16. VITRAIL: Acquisition, Modeling, and Rendering of Stained Glass.

    PubMed

    Thanikachalam, Niranjan; Baboulaz, Loic; Prandoni, Paolo; Trumpler, Stefan; Wolf, Sophie; Vetterli, Martin

    2016-10-01

    Stained glass windows are designed to reveal their powerful artistry under diverse and time-varying lighting conditions; virtual relighting of stained glass, therefore, represents an exceptional tool for the appreciation of this age old art form. However, as opposed to most other artifacts, stained glass windows are extremely difficult if not impossible to analyze using controlled illumination because of their size and position. In this paper, we present novel methods built upon image based priors to perform virtual relighting of stained glass artwork by acquiring the actual light transport properties of a given artifact. In a preprocessing step, we build a material-dependent dictionary for light transport by studying the scattering properties of glass samples in a laboratory setup. We can now use the dictionary to recover a light transport matrix in two ways: under controlled illuminations the dictionary constitutes a sparsifying basis for a compressive sensing acquisition, while in the case of uncontrolled illuminations the dictionary is used to perform sparse regularization. The proposed basis preserves volume impurities and we show that the retrieved light transport matrix is heterogeneous, as in the case of real world objects. We present the rendering results of several stained glass artifacts, including the Rose Window of the Cathedral of Lausanne, digitized using the presented methods. PMID:27416590

  17. TransCut: interactive rendering of translucent cutouts.

    PubMed

    Li, Dongping; Sun, Xin; Ren, Zhong; Lin, Stephen; Tong, Yiying; Guo, Baining; Zhou, Kun

    2013-03-01

    We present TransCut, a technique for interactive rendering of translucent objects undergoing fracturing and cutting operations. As the object is fractured or cut open, the user can directly examine and intuitively understand the complex translucent interior, as well as edit material properties through painting on cross sections and recombining the broken pieces—all with immediate and realistic visual feedback. This new mode of interaction with translucent volumes is made possible with two technical contributions. The first is a novel solver for the diffusion equation (DE) over a tetrahedral mesh that produces high-quality results comparable to the state-of-art finite element method (FEM) of Arbree et al. but at substantially higher speeds. This accuracy and efficiency is obtained by computing the discrete divergences of the diffusion equation and constructing the DE matrix using analytic formulas derived for linear finite elements. The second contribution is a multiresolution algorithm to significantly accelerate our DE solver while adapting to the frequent changes in topological structure of dynamic objects. The entire multiresolution DE solver is highly parallel and easily implemented on the GPU. We believe TransCut provides a novel visual effect for heterogeneous translucent objects undergoing fracturing and cutting operations. PMID:23307612

  18. General RNA binding proteins render translation cap dependent.

    PubMed Central

    Svitkin, Y V; Ovchinnikov, L P; Dreyfuss, G; Sonenberg, N

    1996-01-01

    Translation in rabbit reticulocyte lysate is relatively independent of the presence of the mRNA m7G cap structure and the cap binding protein, eIF-4E. In addition, initiation occurs frequently at spurious internal sites. Here we show that a critical parameter which contributes to cap-dependent translation is the amount of general RNA binding proteins in the extract. Addition of several general RNA binding proteins, such as hnRNP A1, La autoantigen, pyrimidine tract binding protein (hnRNP I/PTB) and the major core protein of cytoplasmic mRNP (p50), rendered translation in a rabbit reticulocyte lysate cap dependent. These proteins drastically inhibited the translation of an uncapped mRNA, but had no effect on translation of a capped mRNA. Based on these and other results, we suggest that one function of general mRNA binding proteins in the cytoplasm is to promote ribosome binding by a 5' end, cap-mediated mechanism, and prevent spurious initiations at aberrant translation start sites. Images PMID:9003790

  19. IRAS colors of carbon stars - An optical spectroscopic test

    SciTech Connect

    Cohen, M.; Wainscoat, R.J.; Walker, H.J.; Volk, K.; Schwartz, D.E.; Search for Extraterrestrial Intelligence Institute, Los Altos, CA )

    1989-06-01

    Optical spectra are obtained of 57 photographic counterparts to IRAS sources not previously studied spectroscopically, and expected on the basis of their IRAS colors to be M or C type stars. Confirmed carbon stars are found only in a restricted range of 12-25 index, and constitute a striking vertical sequence in the 12-25-60 micron color-color diagram. This sequence is in accord with evolutionary models for AGB stars that convert M into C stars by dredge-up, and follow loops in the color-color plane. Optically visible and optically invisible carbon stars occupy different color-color locations consistent with their representations of different evolutionary states in the life of relatively low-mass stars. 16 refs.

  20. IRAS colors of carbon stars - An optical spectroscopic test

    NASA Technical Reports Server (NTRS)

    Cohen, Martin; Wainscoat, Richard J.; Walker, Helen J.; Volk, Kevin; Schwartz, Deborah E.

    1989-01-01

    Optical spectra are obtained of 57 photographic counterparts to IRAS sources not previously studied spectroscopically, and expected on the basis of their IRAS colors to be M or C type stars. Confirmed carbon stars are found only in a restricted range of 12-25 index, and constitute a striking 'vertical' sequence in the 12-25-60 micron color-color diagram. This sequence is in accord with evolutionary models for AGB stars that convert M into C stars by dredge-up, and follow loops in the color-color plane. Optically visible and optically invisible carbon stars occupy different color-color locations consistent with their representations of different evolutionary states in the life of relatively low-mass stars.

  1. Industrial Color Inspection

    NASA Astrophysics Data System (ADS)

    McCamy, C. S.

    1986-10-01

    Color is a very important property of many products and an essential feature of some. The commercial value of color is evident in the fact that customers reject product that is satisfactory in every other way, but is not the right color. Color isrumerically specified, measured, and controlled just as length or weight are. It has three dimensions: Hue, Value, and Chroma, and may be represented in a three-dimensional space. Colors of objects depend on the illumination and pairs of colors may match in one light but not in another. Controlled illumination is required for color matching. Illuminants were standardized by the International Commission on Illumination (CIE). As a basis for color measurement, the CIE adopted three spectral sensitivity functions representing a standard observer. Color may be measured by instruments using standard illumination and simulating the standard observer. It is better to measure spectral reflectance or transmittance and compute colorimetric quantities. Color may be inspected on a production line and the data obtained can be used to control the process. When production cannot be controlled as precisely as required, product may be sorted by color.

  2. Watermarking spot colors

    NASA Astrophysics Data System (ADS)

    Alattar, Osama M.; Reed, Alastair M.

    2003-06-01

    Watermarking of printed materials has usually focused on process inks of cyan, magenta, yellow and black (CMYK). In packaging, almost three out of four printed materials include spot colors. Spot colors are special premixed inks, which can be produced in a vibrant range of colors, often outside the CMYK color gamut. In embedding a watermark into printed material, a common approach is to modify the luminance value of each pixel in the image. In the case of process color work pieces, the luminance change can be scaled to the C, M, Y and K channels using a weighting function, to produce the desired change in luminance. In the case of spot color art designs, there is only one channel available and the luminance change is applied to this channel. In this paper we develop a weighting function to embed the watermark signal across the range of different spot colors. This weighting function normalizes visibility effect and signal robustness across a wide range of different spot colors. It normalizes the signal robustness level over the range of an individual spot color"s intensity levels. Further, it takes into account the sensitivity of the capturing device to the different spot colors.

  3. Acquired color vision deficiency.

    PubMed

    Simunovic, Matthew P

    2016-01-01

    Acquired color vision deficiency occurs as the result of ocular, neurologic, or systemic disease. A wide array of conditions may affect color vision, ranging from diseases of the ocular media through to pathology of the visual cortex. Traditionally, acquired color vision deficiency is considered a separate entity from congenital color vision deficiency, although emerging clinical and molecular genetic data would suggest a degree of overlap. We review the pathophysiology of acquired color vision deficiency, the data on its prevalence, theories for the preponderance of acquired S-mechanism (or tritan) deficiency, and discuss tests of color vision. We also briefly review the types of color vision deficiencies encountered in ocular disease, with an emphasis placed on larger or more detailed clinical investigations.

  4. True Colors Shining Through

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image mosaic illustrates how scientists use the color calibration targets (upper left) located on both Mars Exploration Rovers to fine-tune the rovers' sense of color. In the center, spectra, or light signatures, acquired in the laboratory of the colored chips on the targets are shown as lines. Actual data from Mars Exploration Rover Spirit's panoramic camera is mapped on top of these lines as dots. The plot demonstrates that the observed colors of Mars match the colors of the chips, and thus approximate the red planet's true colors. This finding is further corroborated by the picture taken on Mars of the calibration target, which shows the colored chips as they would appear on Earth.

  5. Points based reconstruction and rendering of 3D shapes from large volume dataset

    NASA Astrophysics Data System (ADS)

    Zhao, Mingchang; Tian, Jie; He, Huiguang; Li, Guangming

    2003-05-01

    In the field of medical imaging, researchers often need visualize lots of 3D datasets to get the informaiton contained in these datasets. But the huge data genreated by modern medical imaging device challenge the real time processing and rendering algorithms at all the time. Spurring by the great achievement of Points Based Rendering (PBR) in the fields of computer graphics to render very large meshes, we propose a new algorithm to use the points as basic primitive of surface reconstruction and rendering to interactively reconstruct and render very large volume dataset. By utilizing the special characteristics of medical image datasets, we obtain a fast and efficient points-based reconstruction and rendering algorithm in common PC. The experimental results show taht this algorithm is feasible and efficient.

  6. New light field camera based on physical based rendering tracing

    NASA Astrophysics Data System (ADS)

    Chung, Ming-Han; Chang, Shan-Ching; Lee, Chih-Kung

    2014-03-01

    Even though light field technology was first invented more than 50 years ago, it did not gain popularity due to the limitation imposed by the computation technology. With the rapid advancement of computer technology over the last decade, the limitation has been uplifted and the light field technology quickly returns to the spotlight of the research stage. In this paper, PBRT (Physical Based Rendering Tracing) was introduced to overcome the limitation of using traditional optical simulation approach to study the light field camera technology. More specifically, traditional optical simulation approach can only present light energy distribution but typically lack the capability to present the pictures in realistic scenes. By using PBRT, which was developed to create virtual scenes, 4D light field information was obtained to conduct initial data analysis and calculation. This PBRT approach was also used to explore the light field data calculation potential in creating realistic photos. Furthermore, we integrated the optical experimental measurement results with PBRT in order to place the real measurement results into the virtually created scenes. In other words, our approach provided us with a way to establish a link of virtual scene with the real measurement results. Several images developed based on the above-mentioned approaches were analyzed and discussed to verify the pros and cons of the newly developed PBRT based light field camera technology. It will be shown that this newly developed light field camera approach can circumvent the loss of spatial resolution associated with adopting a micro-lens array in front of the image sensors. Detailed operational constraint, performance metrics, computation resources needed, etc. associated with this newly developed light field camera technique were presented in detail.

  7. Reactivation of fear memory renders consolidated amygdala synapses labile.

    PubMed

    Kim, Jeongyeon; Song, Beomjong; Hong, Ingie; Kim, Jihye; Lee, Junuk; Park, Sungmo; Eom, Jae Yong; Lee, C Justin; Lee, Sukwon; Choi, Sukwoo

    2010-07-14

    It is believed that memory reactivation transiently renders consolidated memory labile and that this labile or deconsolidated memory is reconsolidated in a protein synthesis-dependent manner. The synaptic correlate of memory deconsolidation upon reactivation, however, has not been fully characterized. Here, we show that 3,5-dihydroxyphenylglycine (DHPG), an agonist for group I metabotropic glutamate receptors (mGluRI), induces synaptic depotentiation only at thalamic input synapses onto the lateral amygdala (T-LA synapses) where synaptic potentiation is consolidated, but not at synapses where synaptic potentiation is not consolidated. Using this mGluRI-induced synaptic depotentiation (mGluRI-depotentiation) as a marker of consolidated synapses, we found that mGluRI-depotentiation correlated well with the state of memory deconsolidation and reconsolidation in a predictable manner. DHPG failed to induce mGluRI-depotentiation in slices prepared immediately after reactivation when the reactivated memory was deconsolidated. DHPG induced mGluRI-depotentiation 1 h after reactivation when the reactivated memory was reconsolidated, but it failed to do so when reconsolidation was blocked by a protein synthesis inhibitor. To test the memory-specificity of mGluRI-depotentiation, conditioned fear was acquired twice using two discriminative tones (2.8 and 20 kHz). Under this condition, mGluRI-depotentiation was fully impaired in slices prepared immediately after reactivation with both tones, whereas mGluRI-depotentiation was partially impaired immediately after reactivation with the 20 kHz tone. Consistently, microinjection of DHPG into the LA 1 h after reactivation reduced fear memory retention, whereas DHPG injection immediately after reactivation failed to do so. Our findings suggest that, upon memory reactivation, consolidated T-LA synapses enter a temporary labile state, displaying insensitivity to mGluRI-depotentiation.

  8. Colors, colored overlays, and reading skills

    PubMed Central

    Uccula, Arcangelo; Enna, Mauro; Mulatti, Claudio

    2014-01-01

    In this article, we are concerned with the role of colors in reading written texts. It has been argued that colored overlays applied above written texts positively influence both reading fluency and reading speed. These effects would be particularly evident for those individuals affected by the so called Meares-Irlen syndrome, i.e., who experience eyestrain and/or visual distortions – e.g., color, shape, or movement illusions – while reading. This condition would interest the 12–14% of the general population and up to the 46% of the dyslexic population. Thus, colored overlays have been largely employed as a remedy for some aspects of the difficulties in reading experienced by dyslexic individuals, as fluency and speed. Despite the wide use of colored overlays, how they exert their effects has not been made clear yet. Also, according to some researchers, the results supporting the efficacy of colored overlays as a tool for helping readers are at least controversial. Furthermore, the very nature of the Meares-Irlen syndrome has been questioned. Here we provide a concise, critical review of the literature. PMID:25120525

  9. Synthesis of pure white color and its equal power, equal chromatic splitting through a novel 3x3 fiber optic visible multiplexer.

    PubMed

    Kim, Jun Ki; Kim, H R; Tünnermann, Andreas; Oh, K

    2008-10-27

    We report generation of pure-white color by mixing red, green, blue (RGB) lights from LEDs through a novel 3??3 fiber optics color synthesizer (FOCS), which is made of hard plastic cladding fiber (HPCF). The three output ports provided an equal power for the synthesized white color with almost identical CIE color coordinates. The FOCS rendered tunable white color temperature and optical properties of the outputs were experimentally investigated in terms of uniformity in power, photometric luminance, and color coordinate. We further packaged the device and applied to small form factor back light unit (BLU) to show feasibility in illumination uniformity enhancement.

  10. Interactive bibliographical database on color

    NASA Astrophysics Data System (ADS)

    Caivano, Jose L.

    2002-06-01

    The paper describes the methodology and results of a project under development, aimed at the elaboration of an interactive bibliographical database on color in all fields of application: philosophy, psychology, semiotics, education, anthropology, physical and natural sciences, biology, medicine, technology, industry, architecture and design, arts, linguistics, geography, history. The project is initially based upon an already developed bibliography, published in different journals, updated in various opportunities, and now available at the Internet, with more than 2,000 entries. The interactive database will amplify that bibliography, incorporating hyperlinks and contents (indexes, abstracts, keywords, introductions, or eventually the complete document), and devising mechanisms for information retrieval. The sources to be included are: books, doctoral dissertations, multimedia publications, reference works. The main arrangement will be chronological, but the design of the database will allow rearrangements or selections by different fields: subject, Decimal Classification System, author, language, country, publisher, etc. A further project is to develop another database, including color-specialized journals or newsletters, and articles on color published in international journals, arranged in this case by journal name and date of publication, but allowing also rearrangements or selections by author, subject and keywords.

  11. Color Reproduction with a Smartphone

    ERIC Educational Resources Information Center

    Thoms, Lars-Jochen; Colicchia, Giuseppe; Girwidz, Raimund

    2013-01-01

    The world is full of colors. Most of the colors we see around us can be created on common digital displays simply by superposing light with three different wavelengths. However, no mixture of colors can produce a fully pure color identical to a spectral color. Using a smartphone, students can investigate the main features of primary color addition…

  12. Real-time stereographic rendering and display of medical images with programmable GPUs.

    PubMed

    Wang, Xiao Hui; Good, Walter F

    2008-03-01

    The study was to explore the power and feasibility of using programmable graphics processing units (GPUs) for real-time rendering and displaying large 3D medical datasets for stereoscopic display workstation. Lung cancer screening CT images were used for developing GPU-based stereo rendering and displaying. The study was run on a personal computer with a 128 MB NVIDIA Quadro FX 1100 graphics card. The performance of rendering and displaying was measured and compared between GPU-based and central processing unit (CPU)-based programming. The results indicate that GPU-based programming was capable of rendering large 3D datasets at real-time interactive rates with stereographic displays.

  13. Real-time volume rendering of digital medical images on an iOS device

    NASA Astrophysics Data System (ADS)

    Noon, Christian; Holub, Joseph; Winer, Eliot

    2013-03-01

    Performing high quality 3D visualizations on mobile devices, while tantalizingly close in many areas, is still a quite difficult task. This is especially true for 3D volume rendering of digital medical images. Allowing this would empower medical personnel a powerful tool to diagnose and treat patients and train the next generation of physicians. This research focuses on performing real time volume rendering of digital medical images on iOS devices using custom developed GPU shaders for orthogonal texture slicing. An interactive volume renderer was designed and developed with several new features including dynamic modification of render resolutions, an incremental render loop, a shader-based clipping algorithm to support OpenGL ES 2.0, and an internal backface culling algorithm for properly sorting rendered geometry with alpha blending. The application was developed using several application programming interfaces (APIs) such as OpenSceneGraph (OSG) as the primary graphics renderer coupled with iOS Cocoa Touch for user interaction, and DCMTK for DICOM I/O. The developed application rendered volume datasets over 450 slices up to 50-60 frames per second, depending on the specific model of the iOS device. All rendering is done locally on the device so no Internet connection is required.

  14. Spatial Frequency Or Grey Level Pseudo-Color Coding Using Gratings

    NASA Astrophysics Data System (ADS)

    Courjon, D.; Bulabois, J.; Mered, C.

    1986-07-01

    Pseudo-color techniques involve the introduction of colors in a monochromatic image to increase the ability of the human viewer to analyze and memorize the information. Several quantities can be coded in pseudo-color, for example temperature gradient, index variations of transparent materials, spatial frequencies of periodic objects or densities.

  15. The nature of colors

    NASA Astrophysics Data System (ADS)

    da Pos, Osvaldo

    2002-06-01

    Color is a visible aspect of objects and lights, and as such is an objective characteristic of our phenomenal world. Correspondingly also objects and lights are objective, although their subjectivity cannot be disregarded since they belong to our phenomenal world. The distinction between perception and sensation deals with colors seen either in complex displays or in isolation. Reality of colors is apparently challenged by virtual reality, while virtual reality is a good example of what colors are. It seems difficult to combine that aspect of reality colors have in our experience and the concept that colors represent something in the external environment: the distinction between stimulation and perceived object is crucial for understanding the relationships between phenomenal world and physical reality. A modern concept of isomorphism seems useful in interpreting the role of colors. The relationship between the psychological structure of colors and the physical stimulation is enlightened by the analysis of pseudocolors. The perceptual, subjective characteristics of colors go along with the subjectivity of scientific concepts. Colors, emotions, and concepts are all in some people's mind: none of them is independent of the subject mind. Nevertheless they can be communicated from person to person by an appropriate scientific terminology.

  16. Information through color imagery

    USGS Publications Warehouse

    Colvocoresses, Alden P.

    1975-01-01

    The color-sensing capability of the human eye is a powerful tool. In remote sensing we should use color to display data more meaningfully, not to re-create the scene. Color disappears with distance, and features change color with viewing angle. Color infrared film lets us apply color with additional meaning even though we introduce a false color response. Although the marginal gray scale on an ERTS (Earth Resources Technology Satellite) image may indicate balance between the green, red, and infrared bands, and although each band may be printed in a primary color, tests show that we are not fully applying the three primary colors. Therefore, contrast in the green band should be raised. For true three-color remote sensing of the Earth, we must find two generally meaningful signatures in the visible spectrum, or perhaps extend our spectral range. Before turning to costly digital processing we should explore analog processing. Most ERTS users deal with relative spectral radiance; the few concerned with absolute radiance could use the computer-compatible tapes or special annotations. NASA (National Aeronautics and Space Administration), which assigns the range and contrast to the ERTS image, controls processing and could adjust the density range for maximum contrast in any ERTS scene. NASA cannot alter processing for local changes in reflective characteristics of the Earth but could adjust for Sun elevation and optimize the contrast in a given band.

  17. Three-dimensional histogram visualization in different color spaces and applications

    NASA Astrophysics Data System (ADS)

    Marcu, Gabriel G.; Abe, Satoshi

    1995-10-01

    A visualization procedure for the 3D histogram of color images is presented. The procedure assumes that the histogram is available as a table that associates to a pixel color the number of its appearance in the image. The procedure runs for the RGB, YMC, HSV, HSL, L*a*b, and L*u*v color spaces and it is easily extendable to other color spaces if the analytical form of color transformations is available. Each histogram value is represented in the color space as a colored ball, in a position corresponding to the place of the color in the space. A simple drawing procedure is used instead of more complicated 3D rendering techniques. The 3D histogram visualization offers a clear and intuitive representation of the color distribution of the image. The procedure is applied to derive a clusterization technique for color classification and visualize its results, to display comparatively the gamut of different color devices, and to detect the misalignment of the RGB planes of a color image. Diagrams illustrating the visualization procedure are presented for each application.

  18. Colored Diffraction Catastrophes

    NASA Astrophysics Data System (ADS)

    Berry, M. V.; Klein, S.

    1996-03-01

    On fine scales, caustics produced with white light show vividly colored diffraction fringes. For caustics described by the elementary catastrophes of singularity theory, the colors are characteristic of the type of singularity. We study the diffraction colors of the fold and cusp catastrophes. The colors can be simulated computationally as the superposition of monochromatic patterns for different wavelengths. Far from the caustic, where the luminosity contrast is negligible, the fringe colors persist; an asymptotic theory explains why. Experiments with caustics produced by refraction through irregular bathroom-window glass show good agreement with theory. Colored fringes near the cusp reveal fine lines that are not present in any of the monochromatic components; these lines are explained in terms of partial decoherence between rays with widely differing path differences.

  19. Laser color recording unit

    NASA Astrophysics Data System (ADS)

    Jung, E.

    1984-05-01

    A color recording unit was designed for output and control of digitized picture data within computer controlled reproduction and picture processing systems. In order to get a color proof picture of high quality similar to a color print, together with reduced time and material consumption, a photographic color film material was exposed pixelwise by modulated laser beams of three wavelengths for red, green and blue light. Components of different manufacturers for lasers, acousto-optic modulators and polygon mirrors were tested, also different recording methods as (continuous tone mode or screened mode and with a drum or flatbed recording principle). Besides the application for the graphic arts - the proof recorder CPR 403 with continuous tone color recording with a drum scanner - such a color hardcopy peripheral unit with large picture formats and high resolution can be used in medicine, communication, and satellite picture processing.

  20. Digital color representation

    DOEpatents

    White, James M.; Faber, Vance; Saltzman, Jeffrey S.

    1992-01-01

    An image population having a large number of attributes is processed to form a display population with a predetermined smaller number of attributes which represent the larger number of attributes. In a particular application, the color values in an image are compressed for storage in a discrete lookup table (LUT) where an 8-bit data signal is enabled to form a display of 24-bit color values. The LUT is formed in a sampling and averaging process from the image color values with no requirement to define discrete Voronoi regions for color compression. Image color values are assigned 8-bit pointers to their closest LUT value whereby data processing requires only the 8-bit pointer value to provide 24-bit color values from the LUT.

  1. Colored diffraction catastrophes.

    PubMed Central

    Berry, M V; Klein, S

    1996-01-01

    On fine scales, caustics produced with white light show vividly colored diffraction fringes. For caustics described by the elementary catastrophes of singularity theory, the colors are characteristic of the type of singularity. We study the diffraction colors of the fold and cusp catastrophes. The colors can be simulated computationally as the superposition of monochromatic patterns for different wavelengths. Far from the caustic, where the luminosity contrast is negligible, the fringe colors persist; an asymptotic theory explains why. Experiments with caustics produced by refraction through irregular bathroom-window glass show good agreement with theory. Colored fringes near the cusp reveal fine lines that are not present in any of the monochromatic components; these lines are explained in terms of partial decoherence between rays with widely differing path differences. Images Fig. 1 Fig. 2 Fig. 3 Fig. 6 Fig. 8 Fig. 9 Fig. 10 PMID:11607642

  2. Estimating secondary color.

    PubMed

    Walker, B H

    1993-12-01

    Image quality of a refracting lens system often will be limited by residual secondary color. Information in this paper permits rapid determination of blur spot size, and resulting image quality degradation, due to secondary color for a refracting lens system that has been designed with normal optical glasses and is free of primary color (achromatic). Included here is a brief description of the basic theory involved and an example of how the plotted data are used. PMID:20856581

  3. Measurements of ocean color

    NASA Technical Reports Server (NTRS)

    Hovis, W. A.

    1972-01-01

    An airborne instrument for determining ocean color and measurements made with the instrument are discussed. It was concluded that a clear relationship exists between the chlorophyll concentration and the color of the water. High altitude measurements from 50,000 feet are described and the effects of atmospheric scattering on the energy reaching the sensor are examined. The measured spectrum of ocean color at high and low altitudes is plotted.

  4. Polarization encoded color camera.

    PubMed

    Schonbrun, Ethan; Möller, Guðfríður; Di Caprio, Giuseppe

    2014-03-15

    Digital cameras would be colorblind if they did not have pixelated color filters integrated into their image sensors. Integration of conventional fixed filters, however, comes at the expense of an inability to modify the camera's spectral properties. Instead, we demonstrate a micropolarizer-based camera that can reconfigure its spectral response. Color is encoded into a linear polarization state by a chiral dispersive element and then read out in a single exposure. The polarization encoded color camera is capable of capturing three-color images at wavelengths spanning the visible to the near infrared. PMID:24690806

  5. Crater Floor in Color

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 5 May 2004 This daytime visible color image was collected on November 18, 2003 during the Southern Summer season in Terra Cimmeria.

    This daytime visible color image was collected on September 4, 2002 during the Northern Spring season in Vastitas Borealis. The THEMIS VIS camera is capable of capturing color images of the martian surface using its five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from the use of multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.

    Image information: VIS instrument. Latitude -23.7, Longitude 135.6 East (224.4 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with

  6. Fingers that change color

    MedlinePlus

    ... conditions can cause fingers or toes to change color: Buerger disease Chilblains. Painful inflammation of small blood vessels. Cryoglobulinemia Frostbite Necrotizing vasculitis Peripheral artery disease ...

  7. 3D reconstruction and quantitative assessment method of mitral eccentric regurgitation from color Doppler echocardiography

    NASA Astrophysics Data System (ADS)

    Liu, Qi; Ge, Yi Nan; Wang, Tian Fu; Zheng, Chang Qiong; Zheng, Yi

    2005-10-01

    Based on the two-dimensional color Doppler image in this article, multilane transesophageal rotational scanning method is used to acquire original Doppler echocardiography while echocardiogram is recorded synchronously. After filtering and interpolation, the surface rendering and volume rendering methods are performed. Through analyzing the color-bar information and the color Doppler flow image's superposition principle, the grayscale mitral anatomical structure and color-coded regurgitation velocity parameter were separated from color Doppler flow images, three-dimensional reconstruction of mitral structure and regurgitation velocity distribution was implemented separately, fusion visualization of the reconstructed regurgitation velocity distribution parameter with its corresponding 3D mitral anatomical structures was realized, which can be used in observing the position, phase, direction and measuring the jet length, area, volume, space distribution and severity level of the mitral regurgitation. In addition, in patients with eccentric mitral regurgitation, this new modality overcomes the inherent limitations of two-dimensional color Doppler flow image by depicting the full extent of the jet trajectory, the area of eccentric regurgitation on three-dimensional image was much larger than that on two-dimensional image, the area variation tendency and volume variation tendency of regurgitation have been shown in figure at different angle and different systolic phase. The study shows that three-dimensional color Doppler provides quantitative measurements of eccentric mitral regurgitation that are more accurate and reproducible than conventional color Doppler.

  8. Evaluating Light Source Color Rendition using the IES TM-30-15 Method

    SciTech Connect

    Houser, Kevin W.; Royer, Michael P.; David, Aurelien

    2015-11-30

    A system for evaluating the color rendition of light sources was recently published as IES TM-30-15 IES Method for Evaluating Light Source Color Rendition. The system includes a fidelity index (Rf) to quantify similarity to a reference illuminant, a relative-gamut index (Rg) to quantify saturation relative to a reference illuminant, and a color vector icon that visually presents information about color rendition. The calculation employs CAM02-UCS and uses a newly-developed set of reflectance functions, comprising 99 color evaluation samples (CES). The CES were down-selected from 105,000 real object samples and are uniformly distributed in color space (fairly representing different colors) and wavelength space (avoiding artificial increase of color rendition values by selective optimization).

  9. Color reproduction with a smartphone

    NASA Astrophysics Data System (ADS)

    Thoms, Lars-Jochen; Colicchia, Giuseppe; Girwidz, Raimund

    2013-10-01

    The world is full of colors. Most of the colors we see around us can be created on common digital displays simply by superposing light with three different wavelengths. However, no mixture of colors can produce a fully pure color identical to a spectral color. Using a smartphone, students can investigate the main features of primary color addition and understand how colors are made on digital displays.

  10. 49 CFR Schedule F to Subpart B of... - Affiliate Revenue Data for Services Rendered

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 8 2011-10-01 2011-10-01 false Affiliate Revenue Data for Services Rendered F...—Affiliate Revenue Data for Services Rendered () Greyhound Lines, Inc. () Trailways combined () All study... 6Furnishing of materials and supplies 7Leasing of land, structures, and vehicles 8Purchase of...

  11. 49 CFR Schedule F to Subpart B of... - Affiliate Revenue Data for Services Rendered

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 8 2014-10-01 2014-10-01 false Affiliate Revenue Data for Services Rendered F...—Affiliate Revenue Data for Services Rendered () Greyhound Lines, Inc. () Trailways combined () All study... 6Furnishing of materials and supplies 7Leasing of land, structures, and vehicles 8Purchase of...

  12. 22 CFR 212.35 - Schedule of fees and method of payment for services rendered.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Schedule of fees and method of payment for services rendered. 212.35 Section 212.35 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT PUBLIC INFORMATION Access to Agency Records § 212.35 Schedule of fees and method of payment for services rendered. (a) Definitions. (1) Direct costs...

  13. 22 CFR 212.35 - Schedule of fees and method of payment for services rendered.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Schedule of fees and method of payment for services rendered. 212.35 Section 212.35 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT PUBLIC INFORMATION Access to Agency Records § 212.35 Schedule of fees and method of payment for services rendered. (a) Definitions. (1) Direct costs...

  14. Real-time construction and rendering of three-dimensional occupancy maps

    SciTech Connect

    Jones, J.P.

    1993-03-01

    This paper describes a preliminary sensory system for real-time sensor-based navigation in a three-dimensional, dynamic environment. Data fro a laser range camera are processed on an iWarp parallel computer to create a 3D occupancy map. This map is rendered using raytracing. The construction and rendering consume less than 800 milliseconds.

  15. Real-time construction and rendering of three-dimensional occupancy maps

    SciTech Connect

    Jones, J.P.

    1993-01-01

    This paper describes a preliminary sensory system for real-time sensor-based navigation in a three-dimensional, dynamic environment. Data fro a laser range camera are processed on an iWarp parallel computer to create a 3D occupancy map. This map is rendered using raytracing. The construction and rendering consume less than 800 milliseconds.

  16. 9 CFR 315.1 - Carcasses and parts passed for cooking; rendering into lard or tallow.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Carcasses and parts passed for cooking... PARTS PASSED FOR COOKING § 315.1 Carcasses and parts passed for cooking; rendering into lard or tallow. Carcasses and parts passed for cooking may be rendered into lard in accordance with § 319.702 of...

  17. 9 CFR 315.1 - Carcasses and parts passed for cooking; rendering into lard or tallow.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Carcasses and parts passed for cooking... PARTS PASSED FOR COOKING § 315.1 Carcasses and parts passed for cooking; rendering into lard or tallow. Carcasses and parts passed for cooking may be rendered into lard in accordance with § 319.702 of...

  18. 9 CFR 315.1 - Carcasses and parts passed for cooking; rendering into lard or tallow.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Carcasses and parts passed for cooking... PARTS PASSED FOR COOKING § 315.1 Carcasses and parts passed for cooking; rendering into lard or tallow. Carcasses and parts passed for cooking may be rendered into lard in accordance with § 319.702 of...

  19. 9 CFR 315.1 - Carcasses and parts passed for cooking; rendering into lard or tallow.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Carcasses and parts passed for cooking... PARTS PASSED FOR COOKING § 315.1 Carcasses and parts passed for cooking; rendering into lard or tallow. Carcasses and parts passed for cooking may be rendered into lard in accordance with § 319.702 of...

  20. 9 CFR 315.1 - Carcasses and parts passed for cooking; rendering into lard or tallow.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Carcasses and parts passed for cooking... PARTS PASSED FOR COOKING § 315.1 Carcasses and parts passed for cooking; rendering into lard or tallow. Carcasses and parts passed for cooking may be rendered into lard in accordance with § 319.702 of...

  1. 26 CFR 20.6001-1 - Persons required to keep records and render statements.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... declaration that it is made under penalties of perjury, of facts within his knowledge which the district... thereof. Failure to comply with such a request will render the executor liable to penalties (see section... thereof. Failure on the part of any person to comply with such request will render him liable to...

  2. 26 CFR 20.6001-1 - Persons required to keep records and render statements.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... declaration that it is made under penalties of perjury, of facts within his knowledge which the district... thereof. Failure to comply with such a request will render the executor liable to penalties (see section... thereof. Failure on the part of any person to comply with such request will render him liable to...

  3. 26 CFR 20.6001-1 - Persons required to keep records and render statements.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... declaration that it is made under penalties of perjury, of facts within his knowledge which the district... thereof. Failure to comply with such a request will render the executor liable to penalties (see section... thereof. Failure on the part of any person to comply with such request will render him liable to...

  4. 47 CFR 1.814 - Reports regarding free service rendered the Government for national defense.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Miscellaneous Reports § 1.814 Reports regarding free service rendered the Government for national defense... Government shall file reports in accordance with part 2 of this chapter. ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Reports regarding free service rendered...

  5. 47 CFR 1.814 - Reports regarding free service rendered the Government for national defense.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Miscellaneous Reports § 1.814 Reports regarding free service rendered the Government for national defense... Government shall file reports in accordance with part 2 of this chapter. ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Reports regarding free service rendered...

  6. 47 CFR 1.814 - Reports regarding free service rendered the Government for national defense.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Miscellaneous Reports § 1.814 Reports regarding free service rendered the Government for national defense... Government shall file reports in accordance with part 2 of this chapter. ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Reports regarding free service rendered...

  7. 47 CFR 1.814 - Reports regarding free service rendered the Government for national defense.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Miscellaneous Reports § 1.814 Reports regarding free service rendered the Government for national defense... Government shall file reports in accordance with part 2 of this chapter. ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Reports regarding free service rendered...

  8. 47 CFR 1.814 - Reports regarding free service rendered the Government for national defense.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Miscellaneous Reports § 1.814 Reports regarding free service rendered the Government for national defense... Government shall file reports in accordance with part 2 of this chapter. ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Reports regarding free service rendered...

  9. 1. Photocopy of early 20th century rendering showing aerial veiw, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Photocopy of early 20th century rendering showing aerial veiw, looking south. Rendering owned by the Crawford Auto-Aviation Museum, 10825 East Blvd., Cleveland, Ohio. - Peerless Motor Car Company, East Ninety-third Street & Quincy Avenue, Cleveland, Cuyahoga County, OH

  10. Approaching the exa-scale: a real-world evaluation of rendering extremely large data sets

    SciTech Connect

    Patchett, John M; Ahrens, James P; Lo, Li - Ta; Browniee, Carson S; Mitchell, Christopher J; Hansen, Chuck

    2010-10-15

    Extremely large scale analysis is becoming increasingly important as supercomputers and their simulations move from petascale to exascale. The lack of dedicated hardware acceleration for rendering on today's supercomputing platforms motivates our detailed evaluation of the possibility of interactive rendering on the supercomputer. In order to facilitate our understanding of rendering on the supercomputing platform, we focus on scalability of rendering algorithms and architecture envisioned for exascale datasets. To understand tradeoffs for dealing with extremely large datasets, we compare three different rendering algorithms for large polygonal data: software based ray tracing, software based rasterization and hardware accelerated rasterization. We present a case study of strong and weak scaling of rendering extremely large data on both GPU and CPU based parallel supercomputers using Para View, a parallel visualization tool. Wc use three different data sets: two synthetic and one from a scientific application. At an extreme scale, algorithmic rendering choices make a difference and should be considered while approaching exascale computing, visualization, and analysis. We find software based ray-tracing offers a viable approach for scalable rendering of the projected future massive data sizes.

  11. 31 CFR 515.548 - Services rendered by Cuba to United States aircraft.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Services rendered by Cuba to United... REGULATIONS Licenses, Authorizations, and Statements of Licensing Policy § 515.548 Services rendered by Cuba to United States aircraft. Specific licenses are issued for payment to Cuba of charges for...

  12. Clarifying color category border according to color vision

    NASA Astrophysics Data System (ADS)

    Ichihara, Takumi; Ichihara, Yasuyo G.

    2015-01-01

    We usually recognize color by two kinds of processes. In the first, the color is recognized continually and a small difference in color is recognized. In the second, the color is recognized discretely. This process recognizes a similar color of a certain range as being in the same color category. The small difference in color is ignored. Recognition by using the color category is important for communication using color. It is known that a color vision defect confuses colors on the confusion locus of color. However, the color category of a color vision defect has not been thoroughly researched. If the color category of the color vision defect is clarified, it will become an important key for color universal design. In this research, we classified color stimuli into four categories to check the shape and the border of the color categories of varied color vision. The experimental result was as follows. The border of protanopia is the following three on the CIE 1931 (x, y) chromaticity diagram: y = -0.3068x + 0.4795, y = -0.1906x + 0.4021, y = -0.2624x + 0.3896. The border of deuteranopia is the following three on the CIE 1931 (x, y) chromaticity diagram: y = -0.7931x + 0.7036, y = -0.718x + 0.5966, y = -0.6667x + 0.5061.

  13. Ocean color imagery: Coastal zone color scanner

    NASA Technical Reports Server (NTRS)

    Hovis, W. A.

    1975-01-01

    Investigations into the feasibility of sensing ocean color from high altitude for determination of chlorophyll and sediment distributions were carried out using sensors on NASA aircraft, coordinated with surface measurements carried out by oceanographic vessels. Spectrometer measurements in 1971 and 1972 led to development of an imaging sensor now flying on a NASA U-2 and the Coastal Zone Color Scanner to fly on Nimbus G in 1978. Results of the U-2 effort show the imaging sensor to be of great value in sensing pollutants in the ocean.

  14. Combinatorial gene therapy renders increased survival in cirrhotic rats

    PubMed Central

    2010-01-01

    Background Liver fibrosis ranks as the second cause of death in México's productive-age population. This pathology is characterized by acummulation of fibrillar proteins in hepatic parenchyma causing synthetic and metabolic disfunction. Remotion of excessive fibrous proteins might result in benefit for subjects increasing survival index. The goal of this work was to find whether the already known therapeutical effect of human urokinase Plasminogen Activator and human Matrix Metalloprotease 8 extends survival index in cirrhotic animals. Methods Wistar rats (80 g) underwent chronic intoxication with CCl4: mineral oil for 8 weeks. Cirrhotic animals were injected with a combined dose of Ad-delta-huPA plus Ad-MMP8 (3 × 1011 and 1.5 × 1011 vp/Kg, respectively) or with Ad-beta-Gal (4.5 × 1011) and were killed after 2, 4, 6, 8 and 10 days. Then, liver and serum were collected. An additional set of cirrhotic animals injected with combined gene therapy was also monitored for their probability of survival. Results Only the cirrhotic animals treated with therapeutical genes (Ad-delta-huPA+Ad-MMP-8) showed improvement in liver fibrosis. These results correlated with hydroxyproline determinations. A significant decrement in alpha-SMA and TGF-beta1 gene expression was also observed. Cirrhotic rats treated with Ad-delta-huPA plus Ad-MMP8 had a higher probability of survival at 60 days with respect to Ad-beta-Gal-injected animals. Conclusion A single administration of Ad-delta-huPA plus Ad-MMP-8 is efficient to induce fibrosis regression and increase survival in experimental liver fibrosis. PMID:20509929

  15. Polar Cap Colors

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 12 May 2004 This daytime visible color image was collected on June 6, 2003 during the Southern Spring season near the South Polar Cap Edge.

    The THEMIS VIS camera is capable of capturing color images of the martian surface using its five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from the use of multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.

    Image information: VIS instrument. Latitude -77.8, Longitude 195 East (165 West). 38 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA

  16. Navigation lights color study

    NASA Astrophysics Data System (ADS)

    Barbosa, Jose G.; Alberg, Matthew T.

    2015-05-01

    The chromaticity of navigation lights are defined by areas on the International Commission on Illumination (CIE) 1931 chromaticity diagram. The corner coordinates for these areas are specified in the International Regulations for Prevention of Collisions at Sea, 1972 (72 COLREGS). The navigation light's color of white, red, green, and yellow are bounded by these areas. The chromaticity values specified by the COLREGS for navigation lights were intended for the human visual system (HVS). The HVS can determine the colors of these lights easily under various conditions. For digital color camera imaging systems the colors of these lights are dependent on the camera's color spectral sensitivity, settings, and color correction. At night the color of these lights are used to quickly determine the relative course of vessels. If these lights are incorrectly identified or there is a delay in identifying them this could be a potential safety of ship concern. Vessels that use camera imaging systems exclusively for sight, at night, need to detect, identify, and discriminate navigation lights for navigation and collision avoidance. The introduction of light emitting diode (LED) lights and lights with different spectral signatures have the potential to be imaged very differently with an RGB color filter array (CFA) color camera than with the human eye. It has been found that some green navigation lights' images appear blue verse green. This has an impact on vessels that use camera imaging systems exclusively for navigation. This paper will characterize color cameras ability to properly reproducing navigation lights' color and survey a set of navigation light to determine if they conform to the COLREGS.

  17. INDEX TO 16MM EDUCATIONAL FILMS.

    ERIC Educational Resources Information Center

    University of Southern California, Los Angeles. National Information Center for Educational Media.

    SIXTEEN MILLIMETER EDUCATIONAL FILMS ARE LISTED WITH TITLE, DESCRIPTION, TIME, COLOR/BLACK AND WHITE, PRODUCER CODE NAME, DISTRIBUTER CODE NAME, AND DATE OF PRODUCTION. FILMS ARE LISTED IN TWO WAYS--WITH TITLE ONLY BY SUBJECT IN A SUBJECT MATTER SECTION WHICH HAS AN OUTLINE AND INDEX, AND WITH ALL DATA IN A SECTION WHICH LISTS ALL FILMS…

  18. Method and system for rendering and interacting with an adaptable computing environment

    DOEpatents

    Osbourn, Gordon Cecil; Bouchard, Ann Marie

    2012-06-12

    An adaptable computing environment is implemented with software entities termed "s-machines", which self-assemble into hierarchical data structures capable of rendering and interacting with the computing environment. A hierarchical data structure includes a first hierarchical s-machine bound to a second hierarchical s-machine. The first hierarchical s-machine is associated with a first layer of a rendering region on a display screen and the second hierarchical s-machine is associated with a second layer of the rendering region overlaying at least a portion of the first layer. A screen element s-machine is linked to the first hierarchical s-machine. The screen element s-machine manages data associated with a screen element rendered to the display screen within the rendering region at the first layer.

  19. Color names, color categories, and color-cued visual search: sometimes, color perception is not categorical.

    PubMed

    Brown, Angela M; Lindsey, Delwin T; Guckes, Kevin M

    2011-01-01

    The relation between colors and their names is a classic case study for investigating the Sapir-Whorf hypothesis that categorical perception is imposed on perception by language. Here, we investigate the Sapir-Whorf prediction that visual search for a green target presented among blue distractors (or vice versa) should be faster than search for a green target presented among distractors of a different color of green (or for a blue target among different blue distractors). A. L. Gilbert, T. Regier, P. Kay, and R. B. Ivry (2006) reported that this Sapir-Whorf effect is restricted to the right visual field (RVF), because the major brain language centers are in the left cerebral hemisphere. We found no categorical effect at the Green-Blue color boundary and no categorical effect restricted to the RVF. Scaling of perceived color differences by Maximum Likelihood Difference Scaling (MLDS) also showed no categorical effect, including no effect specific to the RVF. Two models fit the data: a color difference model based on MLDS and a standard opponent-colors model of color discrimination based on the spectral sensitivities of the cones. Neither of these models nor any of our data suggested categorical perception of colors at the Green-Blue boundary, in either visual field.

  20. Dynamic egg color mimicry.

    PubMed

    Hanley, Daniel; Šulc, Michal; Brennan, Patricia L R; Hauber, Mark E; Grim, Tomáš; Honza, Marcel

    2016-06-01

    Evolutionary hypotheses regarding the function of eggshell phenotypes, from solar protection through mimicry, have implicitly assumed that eggshell appearance remains static throughout the laying and incubation periods. However, recent research demonstrates that egg coloration changes over relatively short, biologically relevant timescales. Here, we provide the first evidence that such changes impact brood parasite-host eggshell color mimicry during the incubation stage. First, we use long-term data to establish how rapidly the Acrocephalus arundinaceus Linnaeus (great reed warbler) responded to natural parasitic eggs laid by the Cuculus canorus Linnaeus (common cuckoo). Most hosts rejected parasitic eggs just prior to clutch completion, but the host response period extended well into incubation (~10 days after clutch completion). Using reflectance spectrometry and visual modeling, we demonstrate that eggshell coloration in the great reed warbler and its brood parasite, the common cuckoo, changes rapidly, and the extent of eggshell color mimicry shifts dynamically over the host response period. Specifically, 4 days after being laid, the host should notice achromatic color changes to both cuckoo and warbler eggs, while chromatic color changes would be noticeable after 8 days. Furthermore, we demonstrate that the perceived match between host and cuckoo eggshell color worsened over the incubation period. These findings have important implications for parasite-host coevolution dynamics, because host egg discrimination may be aided by disparate temporal color changes in host and parasite eggs. PMID:27516874

  1. Requirements for color technology

    NASA Astrophysics Data System (ADS)

    Campbell, Ronald B., Jr.

    1993-06-01

    The requirements for color technology in the general office are reviewed. The two most salient factors driving the requirements for color are the information explosion and the virtually negligible growth in white collar productivity in the recent past. Accordingly, the business requirement upon color technology is that it be utilized in an effective and efficient manner to increase office productivity. Recent research on productivity and growth has moved beyond the classical two factor productivity model of labor and capital to explicitly include knowledge as a third and vital factor. Documents are agents of knowledge in the general office. Documents articulate, express, disseminate, and communicate knowledge. The central question addressed here is how can color, in conjunction with other techniques such as graphics and document design, improve the growth of knowledge? The central thesis is that the effective use of color to convert information into knowledge is one of the most powerful ways to increase office productivity. Material on the value of color is reviewed. This material is related to the role of documents. Document services are the way in which users access and utilize color technology. The requirements for color technology are then defined against the services taxonomy.

  2. Colorful Underwater Sea Creatures

    ERIC Educational Resources Information Center

    McCutcheon, Heather

    2011-01-01

    In this article, the author describes a project wherein students created colorful underwater sea creatures. This project began with a discussion about underwater sea creatures and how they live. The first step was making the multi-colored tissue paper that would become sea creatures and seaweed. Once students had the shapes of their sea creatures…

  3. 3-D Color Wheels

    ERIC Educational Resources Information Center

    DuBois, Ann

    2010-01-01

    The blending of information from an academic class with projects from art class can do nothing but strengthen the learning power of the student. Creating three-dimensional color wheels provides the perfect opportunity to combine basic geometry knowledge with color theory. In this article, the author describes how her seventh-grade painting…

  4. Drawing Color Lines.

    ERIC Educational Resources Information Center

    Gude, Olivia

    2000-01-01

    Addresses the teaching of color symbolism and asserts that racism is embodied and perpetuated through conventional notions of black and white symbolism. Discusses a project with two eighth grade classes, focusing on the discussion of color symbolism in school and popular culture. Considers the importance of analyzing contemporary languages of…

  5. Dynamic egg color mimicry.

    PubMed

    Hanley, Daniel; Šulc, Michal; Brennan, Patricia L R; Hauber, Mark E; Grim, Tomáš; Honza, Marcel

    2016-06-01

    Evolutionary hypotheses regarding the function of eggshell phenotypes, from solar protection through mimicry, have implicitly assumed that eggshell appearance remains static throughout the laying and incubation periods. However, recent research demonstrates that egg coloration changes over relatively short, biologically relevant timescales. Here, we provide the first evidence that such changes impact brood parasite-host eggshell color mimicry during the incubation stage. First, we use long-term data to establish how rapidly the Acrocephalus arundinaceus Linnaeus (great reed warbler) responded to natural parasitic eggs laid by the Cuculus canorus Linnaeus (common cuckoo). Most hosts rejected parasitic eggs just prior to clutch completion, but the host response period extended well into incubation (~10 days after clutch completion). Using reflectance spectrometry and visual modeling, we demonstrate that eggshell coloration in the great reed warbler and its brood parasite, the common cuckoo, changes rapidly, and the extent of eggshell color mimicry shifts dynamically over the host response period. Specifically, 4 days after being laid, the host should notice achromatic color changes to both cuckoo and warbler eggs, while chromatic color changes would be noticeable after 8 days. Furthermore, we demonstrate that the perceived match between host and cuckoo eggshell color worsened over the incubation period. These findings have important implications for parasite-host coevolution dynamics, because host egg discrimination may be aided by disparate temporal color changes in host and parasite eggs.

  6. Image color reduction method for color-defective observers using a color palette composed of 20 particular colors

    NASA Astrophysics Data System (ADS)

    Sakamoto, Takashi

    2015-01-01

    This study describes a color enhancement method that uses a color palette especially designed for protan and deutan defects, commonly known as red-green color blindness. The proposed color reduction method is based on a simple color mapping. Complicated computation and image processing are not required by using the proposed method, and the method can replace protan and deutan confusion (p/d-confusion) colors with protan and deutan safe (p/d-safe) colors. Color palettes for protan and deutan defects proposed by previous studies are composed of few p/d-safe colors. Thus, the colors contained in these palettes are insufficient for replacing colors in photographs. Recently, Ito et al. proposed a p/dsafe color palette composed of 20 particular colors. The author demonstrated that their p/d-safe color palette could be applied to image color reduction in photographs as a means to replace p/d-confusion colors. This study describes the results of the proposed color reduction in photographs that include typical p/d-confusion colors, which can be replaced. After the reduction process is completed, color-defective observers can distinguish these confusion colors.

  7. Are corals colorful?

    PubMed

    Matz, Mikhail V; Marshall, N Justin; Vorobyev, Misha

    2006-01-01

    Using in situ spectrometry data and visual system modeling, we investigate whether the colors conferred to the reef-building corals by GFP-like proteins would look colorful not only to humans, but also to fish occupying different ecological niches on the reef. Some GFP-like proteins, most notably fluorescent greens and nonfluorescent chromoproteins, indeed generate intense color signals. An unexpected finding was that fluorescent proteins might also make corals appear less colorful to fish, counterbalancing the effect of absorption by the photosynthetic pigments of the endosymbiotic algae, which might be a form of protection against herbivores. We conclude that GFP-determined coloration of corals may be an important factor in visual ecology of the reef fishes.

  8. "Focal" Color Areas and the Development of Color Names

    ERIC Educational Resources Information Center

    Heider, Eleanor Rosch

    1971-01-01

    Three experiments using 3- and 4-year-olds as subjects tested the hypothesis that focal colors are more salient than nonfocal colors for young children and are the areas to which color names initially become attached. (NH)

  9. Perceptual Dominant Color Extraction by Multidimensional Particle Swarm Optimization

    NASA Astrophysics Data System (ADS)

    Kiranyaz, Serkan; Uhlmann (Eurasip Member), Stefan; Ince, Turker; Gabbouj, Moncef

    2010-12-01

    Color is the major source of information widely used in image analysis and content-based retrieval. Extracting dominant colors that are prominent in a visual scenery is of utmost importance since the human visual system primarily uses them for perception and similarity judgment. In this paper, we address dominant color extraction as a dynamic clustering problem and use techniques based on Particle Swarm Optimization (PSO) for finding optimal (number of) dominant colors in a given color space, distance metric and a proper validity index function. The first technique, so-called Multidimensional (MD) PSO can seek both positional and dimensional optima. Nevertheless, MD PSO is still susceptible to premature convergence due to lack of divergence. To address this problem we then apply Fractional Global Best Formation (FGBF) technique. In order to extract perceptually important colors and to further improve the discrimination factor for a better clustering performance, an efficient color distance metric, which uses a fuzzy model for computing color (dis-) similarities over HSV (or HSL) color space is proposed. The comparative evaluations against MPEG-7 dominant color descriptor show the superiority of the proposed technique.

  10. An Architecture For Shared Multi-User Client Rendering Of Massive Geodatasets

    NASA Astrophysics Data System (ADS)

    Al-Naser, A.; Brooke, J.; Rasheed, M.; Irving, D. H.

    2012-12-01

    result of user geological interpretations with what we call 'features'. A feature is a logical subset of the original data with each key-value pair tagged as belonging to a particular spatial feature. Thus, instead of a surface being considered as composed of polygons it is now a tagged subset of the data. Our architecture requires an intermediate stage which builds in real-time a volume in a format which can be directly rendered on a client GPU. We call this a Feature-Embedded Spatial Volume (FESVo). In this stage we utilize the indexing and parallel capabilities of the database to perform parallel queries, and on-the-fly down-sampling if lower resolution is required, at a complexity of O(k), where k is the number of data units fetched from the database, similar to searching complexity with the bitmapping index method. Also, user interactions with the visualization are saved back to the database as point tags allowing immediate knowledge sharing. We present a technical and functional architecture for a data-centric approach and how it scales to overcome access and analytical latency in client-server data interactions. Preliminary experimental evaluation shows potential advantages of such a system in terms of security and centralised data management for subsurface data visualization systems. Also, we believe that our architecture can lead to a web-based visualization environment for geoscientific data.

  11. Color Universal Design: analysis of color category dependency on color vision type

    NASA Astrophysics Data System (ADS)

    Ichihara, Yasuyo G.; Kojima, Natsuki; Ito, Kei

    2010-01-01

    The present study investigates the tendency of individuals to categorize colors. Humans recognize colors by categorizing them with specific color names such as red, blue, and yellow. When an individual having a certain type of color vision observes an object, they categorize its color using a particular color name and assume that other people will perceive the color in an identical manner. However, there are many variations in human color vision caused by photoreceptor differences in the eye, including red and green confusion. Thus, another person with a different type of color vision may categorize the color using another name. To address this issue, we attempt to determine the differences in the ranges of colors that people with different types of color vision categorize using particular color names. In the modern urban environment, most visual information, including warning signs and notice boards, is coded by color. Finding the common color categories among different types of color vision is an important step towards achieving Color Universal Design, a visual communication method that is viewer-friendly irrespective of color vision type. Herein we report on a systematic comparison between people with common (C-type) and deutan (D-type) color vision. Analysis of protan (P-type) color vision will follow in a subsequent report.

  12. Plant tissue and the color infrared record

    NASA Technical Reports Server (NTRS)

    Pease, R. W.

    1969-01-01

    Green plant tissue should not be considered as having a uniguely high near-infrared reflectance but rather a low visual reflectance. Leaf tissue without chloroplasts appears to reflect well both visual and near infrared wavelengths. The sensitometry of color infrared film is such that a spectral imbalance strongly favoring infrared reflection is necessary to yield a red record. It is the absorption of visual light by chlorophyll that creates the imbalance that makes the typical red record for plants possible. Reflectance measurements of leaves that have been chemically blanched or which have gone into natural chloride decline strongly suggests that it is the rise in the visual reflectance that is most important in removing the imbalance and degrading the red CIR record. The role of water in leaves appears to be that of rendering epidermal membranes translucent so that the underlying chlorophyll controls the reflection rather than the leaf surface.

  13. A direct multi-volume rendering method aiming at comparisons of 3-D images and models.

    PubMed

    Jacq, J J; Roux, C J

    1997-03-01

    We present a new method for direct volume rendering of multiple three-dimensional (3-D) functions using a density emitter model. This work aims at obtaining visual assessment of the results of a 3-D image registration algorithm which operates on anisotropic and non segmented medical data. We first discuss the fundamentals associated with direct, simultaneous rendering of such datasets. Then, we recall the fuzzy classification and fuzzy surface rendering theory within the density emitter model terminology, and propose an extension of standard direct volume rendering that can handle the rendering of two or more 3-D functions; this consists of the definition of merging rules that are applied on emitter clouds. The included rendering applications are related on one hand, to volume-to-volume registration, and on the other hand, to surface-to-volume registration: the first case is concerned with global elastic registration of CT data, and the second one presents fitting of an implicit surface over a CT data subset. In these two medical imaging application cases, our rendering scheme offers a comprehensive appreciation of the relative position of structural information.

  14. COMPANION ANIMALS SYMPOSIUM: Rendered ingredients significantly influence sustainability, quality, and safety of pet food.

    PubMed

    Meeker, D L; Meisinger, J L

    2015-03-01

    The rendering industry collects and safely processes approximately 25 million t of animal byproducts each year in the United States. Rendering plants process a variety of raw materials from food animal production, principally offal from slaughterhouses, but include whole animals that die on farms or in transit and other materials such as bone, feathers, and blood. By recycling these byproducts into various protein, fat, and mineral products, including meat and bone meal, hydrolyzed feather meal, blood meal, and various types of animal fats and greases, the sustainability of food animal production is greatly enhanced. The rendering industry is conscious of its role in the prevention of disease and microbiological control and providing safe feed ingredients for livestock, poultry, aquaculture, and pets. The processing of otherwise low-value OM from the livestock production and meat processing industries through rendering drastically reduces the amount of waste. If not rendered, biological materials would be deposited in landfills, burned, buried, or inappropriately dumped with large amounts of carbon dioxide, ammonia, and other compounds polluting air and water. The majority of rendered protein products are used as animal feed. Rendered products are especially valuable to the livestock and pet food industries because of their high protein content, digestible AA levels (especially lysine), mineral availability (especially calcium and phosphorous), and relatively low cost in relation to their nutrient value. The use of these reclaimed and recycled materials in pet food is a much more sustainable model than using human food for pets. PMID:26020862

  15. Elasticity-based three dimensional ultrasound real-time volume rendering

    NASA Astrophysics Data System (ADS)

    Boctor, Emad M.; Matinfar, Mohammad; Ahmad, Omar; Rivaz, Hassan; Choti, Michael; Taylor, Russell H.

    2009-02-01

    Volumetric ultrasound imaging has not gained wide recognition, despite the availability of real-time 3D ultrasound scanners and the anticipated potential of 3D ultrasound imaging in diagnostic and interventional radiology. Their use, however, has been hindered by the lack of real-time visualization methods that are capable of producing high quality 3D rendering of the target/surface of interest. Volume rendering is a known visualization method, which can display clear surfaces out of the acquired volumetric data, and has an increasing number of applications utilizing CT and MRI data. The key element of any volume rendering pipeline is the ability to classify the target/surface of interest by setting an appropriate opacity function. Practical and successful real-time 3D ultrasound volume rendering can be achieved in Obstetrics and Angio applications where setting these opacity functions can be done rapidly, and reliably. Unfortunately, 3D ultrasound volume rendering of soft tissues is a challenging task due to the presence of significant amount of noise and speckle. Recently, several research groups have shown the feasibility of producing 3D elasticity volume from two consecutive 3D ultrasound scans. This report describes a novel volume rendering pipeline utilizing elasticity information. The basic idea is to compute B-mode voxel opacity from the rapidly calculated strain values, which can also be mixed with conventional gradient based opacity function. We have implemented the volume renderer using GPU unit, which gives an update rate of 40 volume/sec.

  16. COMPANION ANIMALS SYMPOSIUM: Rendered ingredients significantly influence sustainability, quality, and safety of pet food.

    PubMed

    Meeker, D L; Meisinger, J L

    2015-03-01

    The rendering industry collects and safely processes approximately 25 million t of animal byproducts each year in the United States. Rendering plants process a variety of raw materials from food animal production, principally offal from slaughterhouses, but include whole animals that die on farms or in transit and other materials such as bone, feathers, and blood. By recycling these byproducts into various protein, fat, and mineral products, including meat and bone meal, hydrolyzed feather meal, blood meal, and various types of animal fats and greases, the sustainability of food animal production is greatly enhanced. The rendering industry is conscious of its role in the prevention of disease and microbiological control and providing safe feed ingredients for livestock, poultry, aquaculture, and pets. The processing of otherwise low-value OM from the livestock production and meat processing industries through rendering drastically reduces the amount of waste. If not rendered, biological materials would be deposited in landfills, burned, buried, or inappropriately dumped with large amounts of carbon dioxide, ammonia, and other compounds polluting air and water. The majority of rendered protein products are used as animal feed. Rendered products are especially valuable to the livestock and pet food industries because of their high protein content, digestible AA levels (especially lysine), mineral availability (especially calcium and phosphorous), and relatively low cost in relation to their nutrient value. The use of these reclaimed and recycled materials in pet food is a much more sustainable model than using human food for pets.

  17. Interference Colors in Thin Films.

    ERIC Educational Resources Information Center

    Armstrong, H. L.

    1979-01-01

    Explains interference colors in thin films as being due to the removal, or considerable reduction, of a certain color by destructive inteference that results in the complementary color being seen. (GA)

  18. Three-dimensional rendering of segmented object using matlab - biomed 2010.

    PubMed

    Anderson, Jeffrey R; Barrett, Steven F

    2010-01-01

    The three-dimensional rendering of microscopic objects is a difficult and challenging task that often requires specialized image processing techniques. Previous work has been described of a semi-automatic segmentation process of fluorescently stained neurons collected as a sequence of slice images with a confocal laser scanning microscope. Once properly segmented, each individual object can be rendered and studied as a three-dimensional virtual object. This paper describes the work associated with the design and development of Matlab files to create three-dimensional images from the segmented object data previously mentioned. Part of the motivation for this work is to integrate both the segmentation and rendering processes into one software application, providing a seamless transition from the segmentation tasks to the rendering and visualization tasks. Previously these tasks were accomplished on two different computer systems, windows and Linux. This transition basically limits the usefulness of the segmentation and rendering applications to those who have both computer systems readily available. The focus of this work is to create custom Matlab image processing algorithms for object rendering and visualization, and merge these capabilities to the Matlab files that were developed especially for the image segmentation task. The completed Matlab application will contain both the segmentation and rendering processes in a single graphical user interface, or GUI. This process for rendering three-dimensional images in Matlab requires that a sequence of two-dimensional binary images, representing a cross-sectional slice of the object, be reassembled in a 3D space, and covered with a surface. Additional segmented objects can be rendered in the same 3D space. The surface properties of each object can be varied by the user to aid in the study and analysis of the objects. This inter-active process becomes a powerful visual tool to study and understand microscopic objects.

  19. Single-Chromophore-Based Photoswitchable Nanoparticles Enable Dual-Alternating-Color Fluorescence for Unambiguous Live Cell Imaging

    PubMed Central

    Tian, Zhiyuan; Wu, Wuwei; Wan, Wei; Li, Alexander D. Q.

    2009-01-01

    We have developed a class of spiropyran dyes and their fluorescence colors can be reversibly photoswitched from red color to green, blue, or nearly dark, thus alternating between two colors. Such individual dyes emit either one color or the other, but not both simultaneously. These photoswitchable dyes-enabled nanoparticles, however, emit either one pure color or a combination of both colors because the nanoparticle fluorescence originates from multiple dyes therein. As a result, the nanoparticle shines >30 times brighter than the state-of-the-art organic dyes such as fluorescein. Interestingly, these copolymer nanoparticles exhibit tunable non-specific interactions with live cells and nanoparticles containing properly balanced butyl acrylate and acrylamide monomers render essentially very little non-specific binding to live cells. Decorated with HMGA1 protein, these optically switchable dual-color nanoparticles undergo endocytosis and unambiguously identify themselves from fluorescence interference including autofluorescence, thus enabling a new tool for live cell imaging. PMID:19275146

  20. Iridescence color of shells

    NASA Astrophysics Data System (ADS)

    Liu, Yan

    2002-06-01

    Some shells from both salt water and fresh water show the phenomenon of iridescence color. Pearls and mother-of-pearls also display this phenomenon. In the past, the cause of the iridescence color was attributed to interference. A scanning electron microscope (SEM) was used to study the surface structure of the shell of the mollusk Pinctada Margaritifera. There is a groove structure of reflection grating on the surface area in where the iridescence color appears. An optic experiment with a laser obtained a diffraction pattern produced by the reflection grating structure of the shell. The study led to a conclusion that the iridescence color of the shell is caused by diffraction. A SEM image of the shells of an abalone Haliotis Rufescens (red abalone) showed a statistically regularly arranged tile structure that serves as a two-dimensional grating. This grating structure causes the iridescence color of the shell of red abalone. The dominant color of the iridescence of shells is caused by the uneven grating efficiency in the visible wavelength range when a shell functions as a reflection grating. The wavelength of the dominant color should be at or near the wavelength of the maximum efficiency of the grating.

  1. Is color appearance matching necessary?

    NASA Astrophysics Data System (ADS)

    Beretta, Giordano B.

    1994-05-01

    An analysis of why people are willing to spend more money to buy color systems versus monochrome systems shows that the colorimetric methods used in today's color management systems are insufficient. To fulfill the user's requirements, it is necessary to preserve the appearance of color when an electronic image is reproduced. After proposing formal definitions for color perception and for color appearance, I will present two problems requiring an appearance model to solve: the color selection problem, and gamut mapping.

  2. Theoretical aspects of color vision

    NASA Technical Reports Server (NTRS)

    Wolbarsht, M. L.

    1972-01-01

    The three color receptors of Young-Helmholtz and the opponent colors type of information processing postulated by Hering are both present in the human visual system. This mixture accounts for both the phenomena of color matching or hue discrimination and such perceptual qualities of color as the division of the spectrum into color bands. The functioning of the cells in the visual system, especially within the retina, and the relation of this function to color perception are discussed.

  3. TractRender: a new generalized 3D medical image visualization and output platform

    NASA Astrophysics Data System (ADS)

    Hwang, Darryl H.; Tsao, Sinchai; Gajawelli, Niharika; Law, Meng; Lepore, Natasha

    2015-01-01

    Diffusion MRI allows us not only voxelized diffusion characteristics but also the potential to delineate neuronal fiber path through tractography. There is a dearth of flexible open source tractography software programs for visualizing these complicated 3D structures. Moreover, rendering these structures using various shading, lighting, and representations will result in vastly different graphical feel. In addition, the ability to output these objects in various formats increases the utility of this platform. We have created TractRender that leverages openGL features through Matlab, allowing for maximum ease of use but still maintain the flexibility of custom scene rendering.

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

    NASA Astrophysics Data System (ADS)

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

    2012-01-01

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

  5. Evaluation of VIIRS ocean color products

    NASA Astrophysics Data System (ADS)

    Wang, Menghua; Liu, Xiaoming; Jiang, Lide; Son, SeungHyun; Sun, Junqiang; Shi, Wei; Tan, Liqin; Naik, Puneeta; Mikelsons, Karlis; Wang, Xiaolong; Lance, Veronica

    2014-11-01

    ocean color products in support of science research and operational applications. The VIIRS evaluation and monitoring results can be found at the website: http://www.star.nesdis.noaa.gov/sod/mecb/color/index.html.

  6. Colors of the Sky.

    ERIC Educational Resources Information Center

    Bohren, Craig F.; Fraser, Alistair B.

    1985-01-01

    Explains the physical principles which result in various colors of the sky. Topics addressed include: blueness, mystical properties of water vapor, ozone, fluctuation theory of scattering, variation of purity and brightness, and red sunsets and sunrises. (DH)

  7. Color Video Petrography.

    ERIC Educational Resources Information Center

    Nagle, Frederick

    1981-01-01

    Describes the production and use of color videocassettes with an inexpensive, conventional TV camera and an ordinary petrographic microscope. The videocassettes are used in optical mineralogy and petrology courses. (Author/WB)

  8. Urine - abnormal color

    MedlinePlus

    ... can be caused by: Beets, blackberries, or certain food colorings Hemolytic anemia Injury to the kidneys or urinary tract Medicine Porphyria Urinary tract disorders that cause ... or drugs Bilirubin Medicines, including methylene blue Urinary ...

  9. Color harmonization for images

    NASA Astrophysics Data System (ADS)

    Tang, Zhen; Miao, Zhenjiang; Wan, Yanli; Wang, Zhifei

    2011-04-01

    Color harmonization is an artistic technique to adjust a set of colors in order to enhance their visual harmony so that they are aesthetically pleasing in terms of human visual perception. We present a new color harmonization method that treats the harmonization as a function optimization. For a given image, we derive a cost function based on the observation that pixels in a small window that have similar unharmonic hues should be harmonized with similar harmonic hues. By minimizing the cost function, we get a harmonized image in which the spatial coherence is preserved. A new matching function is proposed to select the best matching harmonic schemes, and a new component-based preharmonization strategy is proposed to preserve the hue distribution of the harmonized images. Our approach overcomes several shortcomings of the existing color harmonization methods. We test our algorithm with a variety of images to demonstrate the effectiveness of our approach.

  10. Colored Contact Lens Dangers

    MedlinePlus

    ... Halloween Hazard: The Hidden Dangers of Buying Decorative Contact Lenses Without a Prescription Sep. 26, 2013 It ... the truth." Real People, Real Problems with Colored Contact Lenses Julian: Teenager Blinded In One Eye By ...

  11. Tooth - abnormal colors

    MedlinePlus

    ... thickness of enamel or the calcium or protein content of the enamel. This can cause color changes. Metabolic diseases may ... or coffee Genetic defects that affect the tooth enamel, such as ... from environmental sources (natural high water fluoride levels) ...

  12. THE COLOR GLASS CONDENSATE.

    SciTech Connect

    MCLERRAN,L.

    2001-08-26

    The Color Glass Condensate is a state of high density gluonic matter which controls the high energy limit of hadronic interactions. Its properties are important for the initial conditions for matter produced at RHIC.

  13. Hypergraph coloring complexes

    PubMed Central

    Breuer, Felix; Dall, Aaron; Kubitzke, Martina

    2012-01-01

    The aim of this paper is to generalize the notion of the coloring complex of a graph to hypergraphs. We present three different interpretations of those complexes–a purely combinatorial one and two geometric ones. It is shown, that most of the properties, which are known to be true for coloring complexes of graphs, break down in this more general setting, e.g., Cohen–Macaulayness and partitionability. Nevertheless, we are able to provide bounds for the f- and h-vectors of those complexes which yield new bounds on chromatic polynomials of hypergraphs. Moreover, though it is proven that the coloring complex of a hypergraph has a wedge decomposition, we provide an example showing that in general this decomposition is not homotopy equivalent to a wedge of spheres. In addition, we can completely characterize those hypergraphs whose coloring complex is connected. PMID:23483700

  14. Phoenix Color Targets

    NASA Technical Reports Server (NTRS)

    2008-01-01

    These images of three Phoenix color targets were taken on sols 1 and 2 by the Surface Stereo Imager (SSI) on board the Phoenix lander. The bottom target was imaged in approximate color (SSI's red, green, and blue filters: 600, 530, and 480 nanometers), while the others were imaged with an infrared filter (750 nanometers). All of them will be imaged many times over the mission to monitor the color calibration of the camera. The two at the top show grains 2 to 3 millimeters in size that were likely lifted to the Phoenix deck during landing. Each of the large color chips on each target contains a strong magnet to protect the interior material from Mars' magnetic dust.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  15. Chemistry, Color, and Art.

    ERIC Educational Resources Information Center

    Orna, Mary Virginia

    2001-01-01

    Describes pigments and artists' colors from a chronological perspective. Explains how chemical analysis can be used to distinguish the differences between artists' palettes, identify the evolution of art, and lead to restoration of an art work. (Contains 13 references.) (YDS)

  16. Color vision test

    MedlinePlus

    ... vision problems: Achromatopsia -- complete color blindness , seeing only shades of gray Deuteranopia -- difficulty telling the difference between red/purple and green/purple Protanopia -- difficulty telling the difference between blue/ ...

  17. Hyperspectral imaging of cuttlefish camouflage indicates good color match in the eyes of fish predators

    PubMed Central

    Chiao, Chuan-Chin; Wickiser, J. Kenneth; Allen, Justine J.; Genter, Brock; Hanlon, Roger T.

    2011-01-01

    Camouflage is a widespread phenomenon throughout nature and an important antipredator tactic in natural selection. Many visual predators have keen color perception, and thus camouflage patterns should provide some degree of color matching in addition to other visual factors such as pattern, contrast, and texture. Quantifying camouflage effectiveness in the eyes of the predator is a challenge from the perspectives of both biology and optical imaging technology. Here we take advantage of hyperspectral imaging (HSI), which records full-spectrum light data, to simultaneously visualize color match and pattern match in the spectral and the spatial domains, respectively. Cuttlefish can dynamically camouflage themselves on any natural substrate and, despite their colorblindness, produce body patterns that appear to have high-fidelity color matches to the substrate when viewed directly by humans or with RGB images. Live camouflaged cuttlefish on natural backgrounds were imaged using HSI, and subsequent spectral analysis revealed that most reflectance spectra of individual cuttlefish and substrates were similar, rendering the color match possible. Modeling color vision of potential di- and trichromatic fish predators of cuttlefish corroborated the spectral match analysis and demonstrated that camouflaged cuttlefish show good color match as well as pattern match in the eyes of fish predators. These findings (i) indicate the strong potential of HSI technology to enhance studies of biological coloration and (ii) provide supporting evidence that cuttlefish can produce color-coordinated camouflage on natural substrates despite lacking color vision. PMID:21576487

  18. Hybrid Rendering Architecture for Realtime and Photorealistic Simulation of Robot-Assisted Surgery.

    PubMed

    Müller, Sebastijan; Bihlmaier, Andreas; Irgenfried, Stephan; Wörn, Heinz

    2016-01-01

    In this paper we present a method for combining realtime and non-realtime (photorealistic) rendering with open source software. Realtime rendering provides sufficient realism and is a good choice for most simulation and regression testing purposes in robot-assisted surgery. However, for proper end-to-end testing of the system, some computer vision algorithms require high fidelity images that capture more minute details of the real scene. One of the central practical obstacles to combining both worlds in a uniform way is creating models that are suitable for both kinds of rendering paradigms. We build a modeling pipeline using open source tools that builds on established, open standards for data exchange. The result is demonstrated through a unified model of the medical OpenHELP phantom used in the Gazebo robotics simulator, which can at the same time be rendered with more visual fidelity in the Cycles raytracer. PMID:27046586

  19. 1. PHOTOCOPY OF RENDERING OF PSFS BUILDING BY D.E. SUTTON. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. PHOTOCOPY OF RENDERING OF PSFS BUILDING BY D.E. SUTTON. Date possibly 1929 or 1930, when construction started. - Philadelphia Saving Fund Society, Twelfth & Market Streets, Philadelphia, Philadelphia County, PA

  20. Multi-Grained Level of Detail for Rendering Complex Meshes Using a Hierarchical Seamless Texture Atlas

    SciTech Connect

    Niski, K; Purnomo, B; Cohen, J

    2006-11-06

    Previous algorithms for view-dependent level of detail provide local mesh refinements either at the finest granularity or at a fixed, coarse granularity. The former provides triangle-level adaptation, often at the expense of heavy CPU usage and low triangle rendering throughput; the latter improves CPU usage and rendering throughput by operating on groups of triangles. We present a new multiresolution hierarchy and associated algorithms that provide adaptive granularity. This multi-grained hierarchy allows independent control of the number of hierarchy nodes processed on the CPU and the number of triangles to be rendered on the GPU. We employ a seamless texture atlas style of geometry image as a GPU-friendly data organization, enabling efficient rendering and GPU-based stitching of patch borders. We demonstrate our approach on both large triangle meshes and terrains with up to billions of vertices.

  1. Automatic Skin Color Beautification

    NASA Astrophysics Data System (ADS)

    Chen, Chih-Wei; Huang, Da-Yuan; Fuh, Chiou-Shann

    In this paper, we propose an automatic skin beautification framework based on color-temperature-insensitive skin-color detection. To polish selected skin region, we apply bilateral filter to smooth the facial flaw. Last, we use Poisson image cloning to integrate the beautified parts into the original input. Experimental results show that the proposed method can be applied in varied light source environment. In addition, this method can naturally beautify the portrait skin.

  2. Color planner for designers based on color emotions

    NASA Astrophysics Data System (ADS)

    Cheng, Ka-Man; Xin, John H.; Taylor, Gail

    2002-06-01

    During the color perception process, an associated feeling or emotion is induced in our brains, and this kind of emotion is termed as 'color emotion.' The researchers in the field of color emotions have put many efforts in quantifying color emotions with the standard color specifications and evaluating the influence of hue, lightness and chroma to the color emotions of human beings. In this study, a color planner was derived according to these findings so that the correlation of color emotions and standard color specifications was clearly indicated. Since people of different nationalities usually have different color emotions as different cultural and traditional backgrounds, the subjects in this study were all native Hong Kong Chinese and the color emotion words were all written in Chinese language in the visual assessments. Through the color planner, the designers from different areas, no matter fashion, graphic, interior or web site etc., can select suitable colors for inducing target color emotions to the customers or product-users since different colors convey different meanings to them. In addition, the designers can enhance the functionality and increase the attractiveness of their designed products by selecting suitable colors.

  3. Color television system using single gun color cathode ray tube

    NASA Technical Reports Server (NTRS)

    Gaiser, E. E.; Hilborn, E. H.

    1970-01-01

    Two-primary color and single gun system provides quality differential color and variation in brightness for specific colors by varying current and controlling duty cycle of electron beam. Number of video amplifiers, deflection circuits, and guns required to display color TV picture is reduced and less complex tube is required.

  4. Color-Blindness Study: Color Discrimination on the TICCIT System.

    ERIC Educational Resources Information Center

    Asay, Calvin S.; Schneider, Edward W.

    The question studied whether the specific seven TICCIT system colors used within color coding schemes can be a source of confusion, or not seen at all, by the color-blind segment of target populations. Subjects were 11 color-blind and three normally sighted students at Brigham Young University. After a preliminary training exercise to acquaint the…

  5. Thermochromism in color measurement

    NASA Astrophysics Data System (ADS)

    Hiltunen, Jouni; Mutanen, J.; Jaeaeskelaeinen, Timo; Parkkinen, Jussi P. S.

    2002-06-01

    Accurate color measurements have become more and more important during the past few decades. This is valid not only in physical research but also in industrial production, where the importance of accurate measurements is mainly due to increased quality requirements set by the customers of various goods. The development of technology enables more and more accurate measuring systems. While the accuracy has improved one has noticed, that many unexpected factors affect the color of an object. One of these factors is the temperature of the sample. It is known that for example the reflectance of the ceramic reference tiles used for calibration of colorimeters and spectrophotometers is temperature dependent. This phenomenon is called thermochromism, which is a reversible change of color of the sample as a function of temperature. It may be noticed already at room temperature if the temperature varies few centigrades. Red and orange samples are especially sensitive to temperature variation and may cause difficulties in precise color measurements. We show, how the phenomenon is based on physical processes and not only reflects the instability of red color pigments. We derive simple formulas, which are shown to explain the experimental data. We also discuss the meaning of thermochromism for color measurements, measure the magnitude of it and propose the experimental conditions to avoid this effect.

  6. Color measurement and discrimination

    NASA Technical Reports Server (NTRS)

    Wandell, B. A.

    1985-01-01

    Theories of color measurement attempt to provide a quantative means for predicting whether two lights will be discriminable to an average observer. All color measurement theories can be characterized as follows: suppose lights a and b evoke responses from three color channels characterized as vectors, v(a) and v(b); the vector difference v(a) - v(b) corresponds to a set of channel responses that would be generated by some real light, call it *. According to theory a and b will be discriminable when * is detectable. A detailed development and test of the classic color measurement approach are reported. In the absence of a luminance component in the test stimuli, a and b, the theory holds well. In the presence of a luminance component, the theory is clearly false. When a luminance component is present discrimination judgements depend largely on whether the lights being discriminated fall in separate, categorical regions of color space. The results suggest that sensory estimation of surface color uses different methods, and the choice of method depends upon properties of the image. When there is significant luminance variation a categorical method is used, while in the absence of significant luminance variation judgments are continuous and consistant with the measurement approach.

  7. The color cone.

    PubMed

    Logvinenko, Alexander D

    2015-02-01

    While the notion of a color cone can be found in writings of Maxwell, Helmholtz, Grassmann, and other scientists of the nineteenth century, it has not been clearly defined as yet. In this paper, the color cone is understood as the set of points in the cone excitation space produced by all possible lights. The spectral curve representing all the monochromatic lights is shown not to entirely belong to the color cone boundary, since its ends turn into the color cone interior. The monochromatic lights represented by the fragment of the spectral curve lying on the color cone boundary make up what is called the effective visible spectrum. The color cone is shown to be a convex hull of the conical surface through the fragment of the spectral curve representing the effective visible spectrum. The effective visible spectrum ends are shown to be determined by the photopigment spectral absorbance being independent of the prereceptor filters (e.g., the spectral transmittance of the lense and macular pigment).

  8. Real-time volume rendering of 4D image using 3D texture mapping

    NASA Astrophysics Data System (ADS)

    Hwang, Jinwoo; Kim, June-Sic; Kim, Jae Seok; Kim, In Young; Kim, Sun Il

    2001-05-01

    Four dimensional image is 3D volume data that varies with time. It is used to express deforming or moving object in virtual surgery of 4D ultrasound. It is difficult to render 4D image by conventional ray-casting or shear-warp factorization methods because of their time-consuming rendering time or pre-processing stage whenever the volume data are changed. Even 3D texture mapping is used, repeated volume loading is also time-consuming in 4D image rendering. In this study, we propose a method to reduce data loading time using coherence between currently loaded volume and previously loaded volume in order to achieve real time rendering based on 3D texture mapping. Volume data are divided into small bricks and each brick being loaded is tested for similarity to one which was already loaded in memory. If the brick passed the test, it is defined as 3D texture by OpenGL functions. Later, the texture slices of the brick are mapped into polygons and blended by OpenGL blending functions. All bricks undergo this test. Continuously deforming fifty volumes are rendered in interactive time with SGI ONYX. Real-time volume rendering based on 3D texture mapping is currently available on PC.

  9. High-quality slab-based intermixing method for fusion rendering of multiple medical objects.

    PubMed

    Kim, Dong-Joon; Kim, Bohyoung; Lee, Jeongjin; Shin, Juneseuk; Kim, Kyoung Won; Shin, Yeong-Gil

    2016-01-01

    The visualization of multiple 3D objects has been increasingly required for recent applications in medical fields. Due to the heterogeneity in data representation or data configuration, it is difficult to efficiently render multiple medical objects in high quality. In this paper, we present a novel intermixing scheme for fusion rendering of multiple medical objects while preserving the real-time performance. First, we present an in-slab visibility interpolation method for the representation of subdivided slabs. Second, we introduce virtual zSlab, which extends an infinitely thin boundary (such as polygonal objects) into a slab with a finite thickness. Finally, based on virtual zSlab and in-slab visibility interpolation, we propose a slab-based visibility intermixing method with the newly proposed rendering pipeline. Experimental results demonstrate that the proposed method delivers more effective multiple-object renderings in terms of rendering quality, compared to conventional approaches. And proposed intermixing scheme provides high-quality intermixing results for the visualization of intersecting and overlapping surfaces by resolving aliasing and z-fighting problems. Moreover, two case studies are presented that apply the proposed method to the real clinical applications. These case studies manifest that the proposed method has the outstanding advantages of the rendering independency and reusability.

  10. Indexing Consistency and Quality.

    ERIC Educational Resources Information Center

    Zunde, Pranas; Dexter, Margaret E.

    A measure of indexing consistency is developed based on the concept of 'fuzzy sets'. It assigns a higher consistency value if indexers agree on the more important terms than if they agree on less important terms. Measures of the quality of an indexer's work and exhaustivity of indexing are also proposed. Experimental data on indexing consistency…

  11. Color gamut reduction techniques for printing with custom inks

    NASA Astrophysics Data System (ADS)

    Chosson, Sylvain M.; Hersch, Roger D.

    2001-12-01

    Printing with custom inks is of interest both for artistic purposes and for printing security documents such as banknotes. However, in order to create designs with only a few custom inks, a general purpose high-quality gamut reduction technique is needed. Most existing gamut mapping techniques map an input gamut such as the gamut of a CRT display into the gamut of an output device such as a CMYK printer. In the present contribution, we are interested in printing with up to three custom inks, which in the general case define a rather narrow color gamut compared with the gamut of standard CMYK printers. The proposed color gamut reduction techniques should work for any combination of custom inks and have a smooth and predictable behavior. When the black ink is available, the lightness levels present in the original image remain nearly identical. Original colors with hues outside the target gamut are projected onto the gray axis. Original colors with hues inside the target gamut hues are rendered as faithful as possible. When the black ink is not available, we map the gray axis G into a colored curve G' connecting in the 3D color space the paper white and the darkest available color formed by the superposition of the 3 inks. The mapped gray axis curve G'(a) is given by the Neugebauer equations when enforcing an equal amount a of custom inks c1, c2 and c3. Original lightness values are mapped onto lightness values along that curve. After lightness mapping, hue and saturation mappings are carried out. When the target gamut does not incorporate the gray axis, we divide it into two volumes, one on the desaturated side of the mapped gray axis curve G' and the other on the saturated side of the G' curve. Colors whose hues are not part of the target color gamut are mapped to colors located on the desaturated side of the G' curve. Colors within the set of printable hues remain within the target color gamut and retain as much as possible their original hue and saturation.

  12. Color in Astronomy

    NASA Astrophysics Data System (ADS)

    Brecher, K.

    2002-05-01

    The vocabulary of astronomy is riddled with color terms. Stars are referred to as red or blue - even brown -- though rarely green. Astronomers say light from a star can be "blueshifted" or that it can be "reddened". Color, however, is not a simple one-dimensional physical parameter equal to wavelength or frequency. It is a complex, psychophysical phenomenon involving at least three degrees of freedom - hue, saturation and brightness -- as well as observational context. Nonetheless, many astronomers treat hue alone or hue plus saturation as the same thing as color. A recent report on "the color of the universe" is a case in point (Baldry and Glazebrook, Bull. Am. As. Soc., 34, No. 1, 571, 2002). Even discounting the authors' initial and (possibly) subsequent errors in arriving at a "color" associated with the composite spectrum derived from the 2dF Galaxy Redshift Survey (first reported as "pale turquoise", then "beige"), the method of viewing the light was left vague, and context is important. For example, consider the question "What color is the Moon?" When viewed from Earth, the Moon appears white against the black sky. Place a piece of "average" lunar material in a lighted room, and it will appear dark gray. To most human observers, the 2000 or so naked eye stars observable from the northern hemisphere all appear white, with the few exceptions which look reddish/orange such as Betelgeuse, Arcturus, Aldeberan, Antares and Pollux. Yet the dimmer double star companion to Alberio can appear bluish when viewed beside its much brighter yellowish/orange neighbor if both are viewed by eye through a small aperture, slightly defocused telescope. This presentation will explore several visual phenomena that can help clarify the concept of color in astronomy. Supported in part by NSF grant # DUE-9950551 for "Project LITE: Light Inquiry Through Experiments".

  13. Color Addition and Subtraction Apps

    NASA Astrophysics Data System (ADS)

    Ruiz, Frances; Ruiz, Michael J.

    2015-10-01

    Color addition and subtraction apps in HTML5 have been developed for students as an online hands-on experience so that they can more easily master principles introduced through traditional classroom demonstrations. The evolution of the additive RGB color model is traced through the early IBM color adapters so that students can proceed step by step in understanding mathematical representations of RGB color. Finally, color addition and subtraction are presented for the X11 colors from web design to illustrate yet another real-life application of color mixing.

  14. Metacontrast masking is processed before grapheme-color synesthesia.

    PubMed

    Bacon, Michael Patrick; Bridgeman, Bruce; Ramachandran, Vilayanur S

    2013-01-01

    We investigated the physiological mechanism of grapheme-color synesthesia using metacontrast masking. A metacontrast target is rendered invisible by a mask that is delayed by about 60 ms; the target and mask do not overlap in space or time. Little masking occurs, however, if the target and mask are simultaneous. This effect must be cortical, because it can be obtained dichoptically. To compare the data for synesthetes and controls, we developed a metacontrast design in which nonsynesthete controls showed weaker dichromatic masking (i.e., the target and mask were in different colors) than monochromatic masking. We accomplished this with an equiluminant target, mask, and background for each observer. If synesthetic color affected metacontrast, synesthetes should show monochromatic masking more similar to the weak dichromatic masking among controls, because synesthetes could add their synesthetic color to the monochromatic condition. The target-mask pairs used for each synesthete were graphemes that elicited strong synesthetic colors. We found stronger monochromatic than dichromatic U-shaped metacontrast for both synesthetes and controls, with optimal masking at an asynchrony of 66 ms. The difference in performance between the monochromatic and dichromatic conditions in the synesthetes indicates that synesthesia occurs at a later processing stage than does metacontrast masking.

  15. Color-dulling solid-state sources of light.

    PubMed

    Žukauskas, Artūras; Vaicekauskas, Rimantas; Shur, Michael

    2012-04-23

    The spectral power distributions (SPDs) of solid-state sources were optimized for rendering the highest number of colors with a perceptually noticeable reduction in chroma (dulling) while maintaining the hue distortion below an acceptable threshold. Statistical color rendition indices derived from the analysis of color-shift vectors of 1269 Munsell samples were used in the objective functions for the optimization of SPDs of the color-dulling sources. The starting optimization point was the SPD composed of narrow yellow and blue (YB) emissions, which both dulls colors and distorts hues. Two methods were applied to reduce the hue-distorting effect of the narrow-band YB source. The first method, broadening the spectral bands, yields SPDs similar to that of a dichromatic white light-emitting diode (LED) with the partial conversion of narrow-band blue electroluminescence to wide-band yellow photoluminescence. The second method, multiplying the spectral bands, results in the SPDs similar to those of trichromatic clusters of red, yellow, and blue (RYB) and amber, green, and blue (AGB) LEDs. PMID:22535067

  16. Simulating coronas in color.

    PubMed

    Gedzelman, Stanley D; Lock, James A

    2003-01-20

    Coronas are simulated in color by use of the Mie scattering theory of light by small droplets through clouds of finite optical thickness embedded in a Rayleigh scattering atmosphere. The primary factors that affect color, visibility, and number of rings of coronas are droplet size, width of the size distribution, and cloud optical thickness. The color sequence of coronas and iridescence varies when the droplet radius is smaller than approximately 6-microm. As radius increases to approximately 3.5 microm, new color bands appear at the center of the corona and fade as they move outward. As the radius continues to increase to approximately 6 microm, successively more inner rings become fixed in the manner described by classical diffraction theory, while outer rings continue their outward migration. Wave clouds or rippled cloud segments produce the brightest and most vivid multiple ringed coronas and iridescence because their integrated dropsize distributions along sunbeams are much narrower than in convective or stratiform clouds. The visibility of coronas and the appearance of the background sky vary with cloud optical depth tau. First the corona becomes visible as a white aureole in a blue sky when tau approximately 0.001. Color purity then rapidly increases to an almost flat maximum in the range 0.05 < or = tau < or = 0.5 and then decreases, so coronas are almost completely washed out by a bright gray background when tau > or = 4.

  17. Manifesting color-kinematics duality in the scattering equation formalism

    NASA Astrophysics Data System (ADS)

    Bjerrum-Bohr, N. E. J.; Bourjaily, Jacob L.; Damgaard, Poul H.; Feng, Bo

    2016-09-01

    We prove that the scattering equation formalism for Yang-Mills amplitudes can be used to make manifest the theory's color-kinematics duality. This is achieved through a concrete reduction algorithm which renders this duality manifest term-by-term. The reduction follows from the recently derived set of identities for amplitudes expressed in the scattering equation formalism that are analogous to monodromy relations in string theory. A byproduct of our algorithm is a generalization of the identities among gravity and Yang-Mills amplitudes.

  18. Color Memory of University Students: Influence of Color Experience and Color Characteristic

    ERIC Educational Resources Information Center

    Bynum, Carlisle; Epps, Helen H.; Kaya, Naz

    2006-01-01

    The ability to select a previously viewed color specimen from an array of specimens that differ in hue, value, or chroma varies among individuals, and may be related to one's basic color discrimination ability or to prior experience with color. This study investigated short-term color memory of 40 college students, 20 of whom were interior design…

  19. Hard color-shrinkage for color-image processing of a digital color camera

    NASA Astrophysics Data System (ADS)

    Saito, Takahiro; Ueda, Yasutaka; Fujii, Nobuhiro; Komatsu, Takashi

    2010-01-01

    The classic shrinkage works well for monochrome-image denoising. To utilize inter-channel color correlations, a noisy image undergoes the color-transformation from the RGB to the luminance-and-chrominance color space, and the luminance and the chrominance components are separately denoised. However, this approach cannot cope with signaldependent noise of a digital color camera. To utilize the noise's signal-dependencies, previously we have proposed the soft color-shrinkage where the inter-channel color correlations are directly utilized in the RGB color space. The soft color-shrinkage works well; but involves a large amount of computations. To alleviate the drawback, taking up the l0-l2 optimization problem whose solution yields the hard shrinkage, we introduce the l0 norms of color differences and the l0 norms of color sums into the model, and derive hard color-shrinkage as its solution. For each triplet of three primary colors, the hard color-shrinkage has 24 feasible solutions, and from among them selects the optimal feasible solution giving the minimal energy. We propose a method to control its shrinkage parameters spatially-adaptively according to both the local image statistics and the noise's signal-dependencies, and apply the spatially-adaptive hard color-shrinkage to removal of signal-dependent noise in a shift-invariant wavelet transform domain. The hard color-shrinkage performs mostly better than the soft color-shrinkage, from objective and subjective viewpoints.

  20. Precision of Synesthetic Color Matching Resembles That for Recollected Colors Rather than Physical Colors

    ERIC Educational Resources Information Center

    Arnold, Derek H.; Wegener, Signy V.; Brown, Francesca; Mattingley, Jason B.

    2012-01-01

    Grapheme-color synesthesia is an atypical condition in which individuals experience sensations of color when reading printed graphemes such as letters and digits. For some grapheme-color synesthetes, seeing a printed grapheme triggers a sensation of color, but "hearing" the name of a grapheme does not. This dissociation allowed us to compare the…