Physics and Astronomy › Atomic and Molecular Physics, and Optics

Color Science and Applications

Works Count: 56755

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Description

This cluster of papers focuses on research related to color constancy, colorimetry, spectral reflectance, illuminant estimation, halftoning, LED lighting, spectral imaging, gamut mapping, and the application of neural networks in color science.

Keywords

Color Constancy; Colorimetry; Spectral Reflectance; Illuminant Estimation; Halftoning; Reflectance Reconstruction; LED Lighting; Spectral Imaging; Gamut Mapping; Neural Networks

Vision: Coding and efficiency

1991-01-01

Colin Blakemore , Kraig Adler , Marcia Pointon

Computational Models of Visual Processing

1991-10-24

Michael S. Landy , J. Anthony Movshon

The more than twenty contributions in this book, all new and previously unpublished, provide an up-to-date survey of contemporary research on computational modeling of the visual system. The approaches represented … The more than twenty contributions in this book, all new and previously unpublished, provide an up-to-date survey of contemporary research on computational modeling of the visual system. The approaches represented range from neurophysiology to psychophysics, and from retinal function to the analysis of visual cues to motion, color, texture, and depth. The contributions are linked thematically by a consistent consideration of the links between empirical data and computational models in the study of visual function. An introductory chapter by Edward Adelson and James Bergen gives a new and elegant formalization of the elements of early vision. Subsequent sections treat receptors and sampling, models of neural function, detection and discrimination, color and shading, motion and texture, and 3D shape. Each section is introduced by a brief topical review and summary. Contributors Edward H. Adelson, Albert J. Ahumada, Jr., James R. Bergen, David G. Birch, David H. Brainard, Heinrich H. Bülthoff, Charles Chubb, Nancy J. Coletta, Michael D'Zmura, John P. Frisby, Norma Graham, Norberto M. Grzywacz, P. William Haake, Michael J. Hawken, David J. Heeger, Donald C. Hood, Elizabeth B. Johnston, Daniel Kersten, Michael S. Landy, Peter Lennie, J. Stephen Mansfield, J. Anthony Movshon, Jacob Nachmias, Andrew J. Parker, Denis G. Pelli, Stephen B. Pollard, R. Clay Reid, Robert Shapley, Carlo L. M. Tiana, Brian A. Wandell, Andrew B. Watson, David R. Williams, Hugh R. Wilson, Yuede. Yang, Alan L. Yuille Bradford Books imprint

Introduction to Spectral Analysis

2005-02-01

Peter Stoica , Randolph L. Moses

1. Basic Concepts. 2. Nonparametric Methods. 3. Parametric Methods for Rational Spectra. 4. Parametric Methods for Line Spectra. 5. Filter Bank Methods. 6. Spatial Methods. Appendix A: Linear Algebra and … 1. Basic Concepts. 2. Nonparametric Methods. 3. Parametric Methods for Rational Spectra. 4. Parametric Methods for Line Spectra. 5. Filter Bank Methods. 6. Spatial Methods. Appendix A: Linear Algebra and Matrix Analysis Tools. Appendix B: Cramer-Rao Bound Tools. Bibliography. References Grouped by Subject. Subject Index.

Digital Color Imaging Handbook

2011-01-21

Gaurav Sharma

Color Fundamentals for Digital Imaging, Gaurav Sharma, Xerox Corporation Visual Psychophysics and Color Appearance, Garrett M. Johnson and Mark D. Fairchild, Rochester Institute of Technology Physical Models for Color Prediction, … Color Fundamentals for Digital Imaging, Gaurav Sharma, Xerox Corporation Visual Psychophysics and Color Appearance, Garrett M. Johnson and Mark D. Fairchild, Rochester Institute of Technology Physical Models for Color Prediction, Patrick Emmel, Clariant International Color Management for Digital Imaging Systems, Edward J. Giorgianni, Thomas E. Madden and Kevin E. Spaulding, Eastman Kodak Company Device Characterization, Raja Bala, Xerox Corporation Digital Color Halftones, Charles M Hains, Shen-ge Wang, and Keith T. Knox, Xerox Corporation Human Visual Model Based Color Halftoning, A. Ufuk Agar, Hewlett Packard Company, Farhan A. Baqai, Sony Electronics, and Jan P. Allebach, Purdue University Compression of Color Images, Ricardo de Queiroz, Xerox Corporation Color Quantization, Luc Brun, Universite Reims, Champagne Ardenne and Alain Tremeau, Universite Jean Monnet de Saint-Etienne Gamut Mapping, Jan Morovic, University of Derby Efficient Color Transformation Implementation, Raja Bala and R. Victor Klassen, Xerox Corporation Color Image Processing for Digital Cameras, Ken Parulski and Kevin E. Spaulding, Eastman Kodak Company

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Morphological Image Analysis: Principles and Applications

2000-09-01

Pierre Soille

From the Publisher: The purpose of this book is to provide readers with an in-depth presentation of the principles and applications of morphological image analysis. This is achieved through a … From the Publisher: The purpose of this book is to provide readers with an in-depth presentation of the principles and applications of morphological image analysis. This is achieved through a step by step process starting from the basic morphological operators and extending to the most recent advances which have proven their practical usefulness. This self-contained volume will be valuable to all engineers, scientists, and practitioners interested in the analysis and processing of digital images.

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Digital images and human vision

1994-06-01

Andrew B. Watson

Processing of digital images destined for visual consumption raises many interesting questions regarding human visual sensitivity. This talk will survey some of these questions, including some that have been answered … Processing of digital images destined for visual consumption raises many interesting questions regarding human visual sensitivity. This talk will survey some of these questions, including some that have been answered and some that have not. There will be an emphasis upon visual masking, and a distinction will be drawn between masking due to contrast gain control processes, and due to processes such as hypothesis testing, pattern recognition, and visual search.

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Reporting of Objective Color Measurements

1992-12-01

Raymond G. McGuire

The analysis of color is frequently an important consideration when determining the efficacy of a variety of postharvest treatments.Consumers can easily be influenced by preconceived ideas of how a particular … The analysis of color is frequently an important consideration when determining the efficacy of a variety of postharvest treatments.Consumers can easily be influenced by preconceived ideas of how a particular fruit or vegetable should appear, and marketers often attempt to improve upon what nature has painted.In spite of the significance of color in our work, however, many researchers continue to analyze this characteristic inappropriately.The confusion that results is unnecessary; easily computed and readily understood measures are available to clarify color descriptions for researchers and marketers alike.Specifically, many scientists in the field of market quality, who are using instruments such as the Hunter colorimeter (Hunter Assoc., Reston, Va.) and various Minolta chroma meters (Minolta, Ramsey, N.J.), analyze and publish a set of Cartesian coordinates generated directly by the instrument.These coordinates pinpoint the measured color in a three-dimensional color space.However, without further manipulation, this information does not provide an indication of hue and chroma-aspects of color that are intuitively understood by those in the marketing chain from producer to consumer.These aspects of color are addressed directly in the color chart-based Munsell notation that specifies the elements of perceived color as value (lightness, from black to white on a scale of 0 to 10), chroma (degree of departure from gray toward pure chromatic color), and hue (red, orange, yellow, green, etc.).In contrast, the instrumentally obtained coordinates, CIE 1931 (Y, x, y) or CIE 1976 (L*, a*, b*), provide information on lightness directly but require some computation to yield explicit measures of chroma and hue (Hunter and Harold, 1987).CIE refers to the Commission Internationale de l'Eclairage (International Commission on Illumination).In the CIE 1976 (L*, a*, b*) color space, abbreviated CIELAB, the lightness coefficient, L*, ranges from black = 0 to white

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Color Difference Thresholds in Dentistry

2015-03-01

Rade D. Paravina , Razvan Ghinea , Luis Javier Herrera +7 more

Abstract Purpose The aim of this prospective multicenter study was to determine 50:50% perceptibility threshold ( PT ) and 50:50% acceptability threshold ( AT ) of dental ceramic under simulated … Abstract Purpose The aim of this prospective multicenter study was to determine 50:50% perceptibility threshold ( PT ) and 50:50% acceptability threshold ( AT ) of dental ceramic under simulated clinical settings. Materials and Methods The spectral radiance of 63 monochromatic ceramic specimens was determined using a non‐contact spectroradiometer. A total of 60 specimen pairs, divided into 3 sets of 20 specimen pairs (medium to light shades, medium to dark shades, and dark shades), were selected for psychophysical experiment. The coordinating center and seven research sites obtained the Institutional Review Board (IRB) approvals prior the beginning of the experiment. Each research site had 25 observers, divided into five groups of five observers: dentists— D , dental students— S , dental auxiliaries— A , dental technicians— T , and lay persons— L . There were 35 observers per group (five observers per group at each site ×7 sites), for a total of 175 observers. Visual color comparisons were performed using a viewing booth. T akagi– S ugeno– K ang ( TSK ) fuzzy approximation was used for fitting the data points. The 50:50% PT and 50:50% AT were determined in CIELAB and CIEDE 2000. The t ‐test was used to evaluate the statistical significance in thresholds differences. Results The CIELAB 50:50% PT was Δ E ab = 1.2, whereas 50:50% AT was Δ E ab = 2.7. Corresponding CIEDE 2000 (Δ E 00 ) values were 0.8 and 1.8, respectively. 50:50% PT by the observer group revealed differences among groups D , A , T , and L as compared with 50:50% PT for all observers. The 50:50% AT for all observers was statistically different than 50:50% AT in groups T and L . Conclusion A 50:50% perceptibility and AT s were significantly different. The same is true for differences between two color difference formulas Δ E 00 /Δ E ab . Observer groups and sites showed high level of statistical difference in all thresholds. Clinical Significance Visual color difference thresholds can serve as a quality control tool to guide the selection of esthetic dental materials, evaluate clinical performance, and interpret visual and instrumental findings in clinical dentistry, dental research, and subsequent standardization. The importance of quality control in dentistry is reinforced by increased esthetic demands of patients and dental professionals.

Edge-Based Color Constancy

2007-08-22

Joost van de Weijer , T. Gevers , Arjan Gijsenij

Color constancy is the ability to measure colors of objects independent of the color of the light source. A well-known color constancy method is based on the gray-world assumption which … Color constancy is the ability to measure colors of objects independent of the color of the light source. A well-known color constancy method is based on the gray-world assumption which assumes that the average reflectance of surfaces in the world is achromatic. In this paper, we propose a new hypothesis for color constancy namely the gray-edge hypothesis, which assumes that the average edge difference in a scene is achromatic. Based on this hypothesis, we propose an algorithm for color constancy. Contrary to existing color constancy algorithms, which are computed from the zero-order structure of images, our method is based on the derivative structure of images. Furthermore, we propose a framework which unifies a variety of known (gray-world, max-RGB, Minkowski norm) and the newly proposed gray-edge and higher order gray-edge algorithms. The quality of the various instantiations of the framework is tested and compared to the state-of-the-art color constancy methods on two large data sets of images recording objects under a large number of different light sources. The experiments show that the proposed color constancy algorithms obtain comparable results as the state-of-the-art color constancy methods with the merit of being computationally more efficient.

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Human Vision and the Spectrum

1945-06-29

George Wald

Spectral Distribution of Typical Daylight as a Function of Correlated Color Temperature

1964-08-01

Deane B. Judd , David L. MacAdam , Günter Wyszecki +4 more

Spectral distributions of 622 samples of daylight (skylight, and sunlight plus skylight) have been subjected to characteristic vector analysis, as composite data and in three subgroups (99 distributions measured by … Spectral distributions of 622 samples of daylight (skylight, and sunlight plus skylight) have been subjected to characteristic vector analysis, as composite data and in three subgroups (99 distributions measured by Budde; 249, by Condit; and 274, by Henderson and Hodgkiss). The chromaticity coordinates (x,y) computed from these distributions have been compared with direct visual determinations of chromaticity coordinates of daylight by Nayatani and Wyszecki, and by Chamberlin, Lawrence, and Belbin. It was found that the chromaticities indicated by the spectral distributions and by direct visual colorimetry cluster about the curve: y = 2.870x−3.000x2−0.275. This curve of typical daylight chromaticities falls slightly on the green side of the Planckian locus. From the mean and the first two characteristic vectors of the composite data, spectral distribution curves have been reconstituted by choice of scalar multiples of the vectors such that the chromaticity points fall on the curve of typical daylight chromaticities at places corresponding to correlated color temperatures of 4800°, 5500°, 6500°, 7500°, and 10 000°K. The representative character of these reconstituted spectral-distribution curves has been established by comparison with the measured curves from each subgroup yielding the closest approximation to the same chromaticities. The agreement so found suggests that this family of curves is more representative of the various phases of daylight between correlated color temperatures 4800° and 10 000°K than any previously derived distributions.

The CIEDE2000 color-difference formula: Implementation notes, supplementary test data, and mathematical observations

2004-01-01

Gaurav Sharma , Wencheng Wu , Edul N. Dalal

This article and the associated data and programs provided with it are intended to assist color engineers and scientists in correctly implementing the recently developed CIEDE2000 color-difference formula. We indicate … This article and the associated data and programs provided with it are intended to assist color engineers and scientists in correctly implementing the recently developed CIEDE2000 color-difference formula. We indicate several potential implementation errors that are not uncovered in tests performed using the original sample data published with the standard. A supplemental set of data is provided for comprehensive testing of implementations. The test data, Microsoft Excel spreadsheets, and MATLAB scripts for evaluating the CIEDE2000 color difference are made available at the first author's website. Finally, we also point out small mathematical discontinuities in the formula. © 2004 Wiley Periodicals, Inc. Col Res Appl, 30, 21–30, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20070

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Visual Sensitivities to Color Differences in Daylight*

1942-05-01

David L. MacAdam

An apparatus is described which facilitates the presentation of pairs of variable colors without variation of luminance. With this instrument, various criteria of visual sensitivity to color difference have been … An apparatus is described which facilitates the presentation of pairs of variable colors without variation of luminance. With this instrument, various criteria of visual sensitivity to color difference have been investigated. The standard deviation of color matching was finally adopted as the most reproducible criterion. The test field was two degrees in diameter, divided by a vertical biprism edge, and was viewed centrally with a surrounding field of forty-two degrees diameter uniformly illuminated so as to have a chromaticity similar to that of the I.C.I. Standard Illuminant C (average daylight). The luminance of the test field was maintained constant at 15 millilamberts, and the surrounding field was 7.5 millilamberts. These fields were viewed monocularly through an artificial pupil, 2.6 mm in diameter. Over twenty-five thousand trials at color matching have been recorded for a single observer, and the readings are analyzed in detail and compared with previously available data. The standard deviations of the trials are represented in terms of distance in the standard 1931 I.C.I. chromaticity diagram. These increments of distance are represented as functions of position alongstraight lines in the chromaticity diagram, and also as functions of direction of departure from points representing certain standard chromaticities. Such representations are simpler than the traditional representations of wave-length thresholds and purity thresholds as functions of wave-length, and the accuracy of the representations is improved by this simplicity. Chromaticity discrimination for non-spectral colors is represented simultaneously and on the same basis as for spectral colors. Small, equally noticeable chromaticity differences are represented for all chromaticities and for all kinds of variations by the lengths of the radii of a family of ellipses drawn on the standard chromaticity diagram. These ellipses cannot be transformed into equal-sized circles by any projective transformation of the standard chromaticity diagram. The consistency of these data with the results of other investigators is exhibited in terms of the noticeabilities of wave-length differences in the spectrum and of the noticeabilities of purity differences from a neutral stimulus, as functions of dominant wave-length.

Color Adaptation of Edge-Detectors in the Human Visual System

1965-09-03

Celeste McCollough

An aftereffect of color which depends on the orientation of lines in the test field may be obtained by presenting a horizontal grating of one color alternately with a vertical … An aftereffect of color which depends on the orientation of lines in the test field may be obtained by presenting a horizontal grating of one color alternately with a vertical grating of a different color. Like the aftereffect of adaptation to chromatic fringes produced by prismatic spectacles, this aftereffect is visible in monochromatic light and fails to show inter-ocular transfer. It is suggested that both effects are to be understood in terms of color adaptation of orientation-specific edge-detectors.

Evaluation of linear models of surface spectral reflectance with small numbers of parameters

1986-10-01

Laurence T. Maloney

Recent computational models of color vision demonstrate that it is possible to achieve exact color constancy over a limited range of lights and surfaces described by linear models. The success … Recent computational models of color vision demonstrate that it is possible to achieve exact color constancy over a limited range of lights and surfaces described by linear models. The success of these computational models hinges on whether any sizable range of surface spectral reflectances can be described by a linear model with about three parameters. In the first part of this paper, I analyze two large sets of empirical surface spectral reflectances and examine three conjectures concerning constraints on surface reflectance: (1) that empirical surface reflectances fall within a linear model with a small number of parameters, (2) that empirical surface reflectances fall within a linear model composed of band-limited functions with a small number of parameters, and (3) that the shape of the spectral-sensitivity curves of human vision enhance the fit between empirical surface reflectances and a linear model. I conclude that the first and second conjectures hold for the two sets of spectral reflectances analyzed but that the number of parameters required to model the spectral reflectances is five to seven, not three. A reanalysis of the empirical data that takes human visual sensitivity into account gives more promising results. The linear models derived provide excellent fits to the data with as few as three or four parameters, confirming the third conjecture. The results suggest that constraints on possible surface-reflectance functions and the "filtering" properties of the shapes of the spectral-sensitivity curves of photoreceptors can both contribute to color constancy. In the last part of the paper I derive the relation between the number of photoreceptor classes present in vision and the "filtering" properties of each class. The results of this analysis reverse a conclusion reached by Barlow: the "filtering" properties of human photoreceptors are consistent with a trichromatic visual system that is color constant.

The Measurement of Appearance

1976-07-01

David Foster

"The Measurement of Appearance." Optica Acta: International Journal of Optics, 23(7), pp. 595–596 "The Measurement of Appearance." Optica Acta: International Journal of Optics, 23(7), pp. 595–596

Correlated color temperature as an explicit function of chromaticity coordinates

1992-04-01

C. S. McCamy

A simple equation to compute correlated color temperature (CCT) from CIE 1931 chromaticity coordinates x and y is given. Over the range of interest in color science, the errors are … A simple equation to compute correlated color temperature (CCT) from CIE 1931 chromaticity coordinates x and y is given. Over the range of interest in color science, the errors are negligible. It was derived from the fact that the isotemperature lines for CCTs of principle interest nearly converge toward a point on the chromaticity diagram and the assumption that CCT may be represented by a third-order polynomial function of the reciprocal of the slope of the line from that point to the chromaticity of the light. the equation is useful in designing sources to simulate CIE colorimetric illuminants.

A simple digital imaging method for measuring and analyzing color of food surfaces

2003-07-22

Kit L. Yam , Spyros Papadakis

A spatial processor model for object colour perception

1980-07-01

Gershon Buchsbaum

Gabor filters as texture discriminator

1989-06-01

I. Fogel , Dov Sagi

The Retinex Theory of Color Vision

1977-12-01

Edwin H. Land

Color gamut transform pairs

1978-08-23

Alvy Ray Smith

Digital control of color television monitors—in particular, via frame buffers—has added precise control of a large subset of human colorspace to the capabilities of computer graphics. This subset is the … Digital control of color television monitors—in particular, via frame buffers—has added precise control of a large subset of human colorspace to the capabilities of computer graphics. This subset is the gamut of colors spanned by the red, green, and blue (RGB) electron guns exciting their respective phosphors. It is called the RGB monitor gamut. Full-blown color theory is a quite complex subject involving physics, psychology, and physiology, but restriction to the RGB monitor gamut simplifies matters substantially. It is linear, for example, and admits to familiar spatial representations. This paper presents a set of alternative models of the RGB monitor gamut based on the perceptual variables hue (H), saturation (S), and value (V) or brightness (L). Algorithms for transforming between these models are derived. Particular emphasis is placed on an RGB to HSV non-trigonometric pair of transforms which have been used successfully for about four years in frame buffer painting programs. These are fast, accurate, and adequate in many applications. Computationally more difficult transform pairs are sometimes necessary, however. Guidelines for choosing among the models are provided. Psychophysical corrections are described within the context of the definitions established by the NTSC (National Television Standards Committee).

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Color appearance models

1998-08-01

Michael H. Brill

Galaxy Colors in Various Photometric Band Systems

1995-10-01

M. Fukugita , Kazuhiro Shimasaku , Takashi Ichikawa

A study is made of stellar and galaxy colors using a spectrophotometric synethesis technique. We show that use of good color response functions and a modern determination of the spectroscopic … A study is made of stellar and galaxy colors using a spectrophotometric synethesis technique. We show that use of good color response functions and a modern determination of the spectroscopic energy distribution for a alpha-Lyr gives synthetic colors in a good agreement with photometric observations to about 0.05 mag. The synthetic method then is applied to sutdy galaxy colors using the spectrophotometric atlas of Kennicutt (1992), and a comparison is made with observed galaxy colors. The K-correction is calculated and compared with that of Coleman, Wu and Weedman (1980). We then study colors of galaxies in various photometric band systems and obtain color transformation laws, which enable us to find offsets among different systems. We include 48 photometric bands in our study.

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A spatial extension of CIELAB for digital color‐image reproduction

1997-03-01

Xiaohan Zhang , Brian A. Wandell

Abstract— We describe a spatial extension to the CIELAB color metric that is useful for measuring color reproduction errors of digital images. To compute the error, digital color images are … Abstract— We describe a spatial extension to the CIELAB color metric that is useful for measuring color reproduction errors of digital images. To compute the error, digital color images are spatially filtered using a pattern‐color separable method and then converted into the CIELAB representation. Over patterned regions of the image, the reproduction errors measured using the spatial extension of CIELAB correspond to perceived color errors better than errors computed without the spatial extension. Over uniform spatial regions of the image, errors computed with the extension are equal to errors computed using the standard CIELAB formulae.

Generalized Assorted Pixel Camera: Postcapture Control of Resolution, Dynamic Range, and Spectrum

2010-03-30

Fumihito Yasuma , Tomoo Mitsunaga , Daisuke Iso +1 more

We propose the concept of a generalized assorted pixel (GAP) camera, which enables the user to capture a single image of a scene and, after the fact, control the tradeoff … We propose the concept of a generalized assorted pixel (GAP) camera, which enables the user to capture a single image of a scene and, after the fact, control the tradeoff between spatial resolution, dynamic range and spectral detail. The GAP camera uses a complex array (or mosaic) of color filters. A major problem with using such an array is that the captured image is severely under-sampled for at least some of the filter types. This leads to reconstructed images with strong aliasing. We make four contributions in this paper: 1) we present a comprehensive optimization method to arrive at the spatial and spectral layout of the color filter array of a GAP camera. 2) We develop a novel algorithm for reconstructing the under-sampled channels of the image while minimizing aliasing artifacts. 3) We demonstrate how the user can capture a single image and then control the tradeoff of spatial resolution to generate a variety of images, including monochrome, high dynamic range (HDR) monochrome, RGB, HDR RGB, and multispectral images. 4) Finally, the performance of our GAP camera has been verified using extensive simulations that use multispectral images of real world scenes. A large database of these multispectral images has been made available at http://wwwl.cs.columbia.edu/ CAVE/projects/gap_camera/ for use by the research community.

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Color constancy: a method for recovering surface spectral reflectance

1986-01-01

Laurence T. Maloney , Brian A. Wandell

Human and machine visual sensing is enhanced when surface properties of objects in scenes, including color, can be reliably estimated despite changes in the ambient lighting conditions. We describe a … Human and machine visual sensing is enhanced when surface properties of objects in scenes, including color, can be reliably estimated despite changes in the ambient lighting conditions. We describe a computational method for estimating surface spectral reflectance when the spectral power distribution of the ambient light is not known.

Properties and performance of a center/surround retinex

1997-03-01

Daniel J. Jobson , Zia Ur Rahman , Glenn A. Woodell

The last version of Land's (1986) retinex model for human vision's lightness and color constancy has been implemented and tested in image processing experiments. Previous research has established the mathematical … The last version of Land's (1986) retinex model for human vision's lightness and color constancy has been implemented and tested in image processing experiments. Previous research has established the mathematical foundations of Land's retinex but has not subjected his lightness theory to extensive image processing experiments. We have sought to define a practical implementation of the retinex without particular concern for its validity as a model for human lightness and color perception. We describe the trade-off between rendition and dynamic range compression that is governed by the surround space constant. Further, unlike previous results, we find that the placement of the logarithmic function is important and produces best results when placed after the surround formation. Also unlike previous results, we find the best rendition for a "canonical" gain/offset applied after the retinex operation. Various functional forms for the retinex surround are evaluated, and a Gaussian form is found to perform better than the inverse square suggested by Land. Images that violate the gray world assumptions (implicit to this retinex) are investigated to provide insight into cases where this retinex fails to produce a good rendition.

The CIE 1976 Color‐Difference Formulae

1977-03-01

Alan Robertson

The International Commission on Illumination (CIE) has recommended the use of two approximately uniform color spaces and associated color‐difference formulae chosen from among several of similar merit to promote uniformity … The International Commission on Illumination (CIE) has recommended the use of two approximately uniform color spaces and associated color‐difference formulae chosen from among several of similar merit to promote uniformity of practice. In this paper, the various features of the two formulae are discussed and compared. It is shown that the two are approximately equal in their degree of agreement with visual judgements of color difference. Choice of which formula to use in a particular situation will often depend not so much on scientific merit as on other factors such as familiarity and conformance to common practice in a particular industry or group.

A novel algorithm for color constancy

1990-08-01

David Forsyth

The Amsterdam Library of Object Images

2004-09-28

Jan‐Mark Geusebroek , Gertjan J. Burghouts , A.W.M. Smeulders

The development of the CIE 2000 colour‐difference formula: CIEDE2000

2001-08-28

Ming Ronnier Luo , Guihua Cui , B. Rigg

Abstract A colour‐difference equation based on CIELAB is developed. It includes not only lightness, chroma, and hue weighting functions, but also an interactive term between chroma and hue differences for … Abstract A colour‐difference equation based on CIELAB is developed. It includes not only lightness, chroma, and hue weighting functions, but also an interactive term between chroma and hue differences for improving the performance for blue colours and a scaling factor for CIELAB a * scale for improving the performance for gray colours. Four reliable colour discrimination datasets based upon object colours were accumulated and combined. The equation was tested together with the other advanced CIELAB based equations using the combined dataset and each individual dataset. It outperformed CMC and CIE94 by a large margin, and predicted better than BFD and LCD. The equation has been officially adopted as the new CIE colour‐difference equation. © 2001 John Wiley & Sons, Inc. Col Res Appl, 26, 340–350, 2001

Color image quantization for frame buffer display

1982-07-01

Paul S. Heckbert

Algorithms for adaptive, tapered quantization of color images are described. The research is motivated by the desire to display high-quality reproductions of color images with small frame buffers. It is … Algorithms for adaptive, tapered quantization of color images are described. The research is motivated by the desire to display high-quality reproductions of color images with small frame buffers. It is demonstrated that many color images which would normally require a frame buffer having 15 bits per pixel can be quantized to 8 or fewer bits per pixel with little subjective degradation. In most cases, the resulting images look significantly better than those made with uniform quantization.

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Color-based object recognition

1999-03-01

Theo Gevers , A.W.M. Smeulders

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Physics of color centers

1968-01-01

W. B. Fowler

Multichannel texture analysis using localized spatial filters

1990-01-01

Alan C. Bovik , Marianna Clark , Wilson S. Geisler

A computational approach for analyzing visible textures is described. Textures are modeled as irradiance patterns containing a limited range of spatial frequencies, where mutually distinct textures differ significantly in their … A computational approach for analyzing visible textures is described. Textures are modeled as irradiance patterns containing a limited range of spatial frequencies, where mutually distinct textures differ significantly in their dominant characterizing frequencies. By encoding images into multiple narrow spatial frequency and orientation channels, the slowly varying channel envelopes (amplitude and phase) are used to segregate textural regions of different spatial frequency, orientation, or phase characteristics. Thus, an interpretation of image texture as a region code, or carrier of region information, is emphasized. The channel filters used, known as the two-dimensional Gabor functions, are useful for these purposes in several senses: they have tunable orientation and radial frequency bandwidths and tunable center frequencies, and they optimally achieve joint resolution in space and in spatial frequency. By comparing the channel amplitude responses, one can detect boundaries between textures. Locating large variations in the channel phase responses allows discontinuities in the texture phase to be detected. Examples are given of both types of texture processing using a variety of real and synthetic textures.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>

Color gamut transform pairs

1978-08-23

Alvy Ray Smith

Digital control of color television monitors—in particular, via frame buffers—has added precise control of a large subset of human colorspace to the capabilities of computer graphics. This subset is the … Digital control of color television monitors—in particular, via frame buffers—has added precise control of a large subset of human colorspace to the capabilities of computer graphics. This subset is the gamut of colors spanned by the red, green, and blue (RGB) electron guns exciting their respective phosphors. It is called the RGB monitor gamut . Full-blown color theory is a quite complex subject involving physics, psychology, and physiology, but restriction to the RGB monitor gamut simplifies matters substantially. It is linear, for example, and admits to familiar spatial representations. This paper presents a set of alternative models of the RGB monitor gamut based on the perceptual variables hue (H), saturation (S), and value (V) or brightness (L). Algorithms for transforming between these models are derived. Particular emphasis is placed on an RGB to HSV non-trigonometric pair of transforms which have been used successfully for about four years in frame buffer painting programs. These are fast, accurate, and adequate in many applications. Computationally more difficult transform pairs are sometimes necessary, however. Guidelines for choosing among the models are provided. Psychophysical corrections are described within the context of the definitions established by the NTSC (National Television Standards Committee).

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<i>Color in Business, Science, and Industry</i>

1963-12-01

Deane B. Judd , Günter Wyszecki , W. T. Wintringham

This book is divided into three parts. Part I outlines the elementary principles of the eye as a sense organ and the basic facts of color vision, including types of … This book is divided into three parts. Part I outlines the elementary principles of the eye as a sense organ and the basic facts of color vision, including types of color blindness and methods of testing. Part II deals with tools and techniques, such as spectrophotometry, standards in colorimetry, and the reproduction of pictures in color. Part III deals with physics and the psychophysics of colorant layers. The book will be useful for all who deal in colors, particularly the manufacturer. The book is a happy combination of science and common sense and is written by one of the outstanding scientists in this field.

A Novel Electrophotographic System

1969-01-01

S. K. Deb

A novel electrophotographic system is described which consists of a thin film of a transition metal oxide and a thin film photoconductive layer sandwiched between a pair of electrodes. When … A novel electrophotographic system is described which consists of a thin film of a transition metal oxide and a thin film photoconductive layer sandwiched between a pair of electrodes. When an electric field is applied across this composite structure and an optical image is projected on it, the resulting modulation of the conductivity pattern in the photoconductive layer causes a similar coloration pattern in the oxide layer, thereby forming a visible image. The formation of color centers and the associated optical and electrical properties are discussed.

Color Science, Concepts and Methods. Quantitative Data and Formulas

1967-10-01

W. D. Wright

This remarkable and unusual book is by two outstanding authorities on the science of colour: Dr. Stiles, for many years a senior member of the Light Division at the National … This remarkable and unusual book is by two outstanding authorities on the science of colour: Dr. Stiles, for many years a senior member of the Light Division at the National Physical Laboratory, and Dr. Wyszecki, currently in charge of the Radiation Optics Section of the Canadian National Research Council. The authors' aim has been to provide a comprehensive source book of data required by the practical and theoretical worker in the field of colour and they have achieved this aim so successfully that their book is likely to become the standard work on the subject and to remain so for a good many years.

Color standards and color nomenclature /

1912-01-01

Robert Ridgway

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Handbook of Transparent Conductors

2010-09-10

David S. Ginley , 秀雄細野 , David C. Paine

The effect of starch‐based sizing techniques on colour measurements in electrophotographic printing

2025-06-25

Ufuk Yılmaz | Coloration Technology

Abstract This study examines the effects of starch‐based coating techniques used in electrophotographic printing on colour measurements. After the coating process using five different types of starch (tapioca, corn, wheat, … Abstract This study examines the effects of starch‐based coating techniques used in electrophotographic printing on colour measurements. After the coating process using five different types of starch (tapioca, corn, wheat, potato, rice), optical and physical tests were performed on the samples, followed by printing using the electrophotographic printing technique. The printing results were then analysed within the colour spectrum, and comparative colour measurements were conducted. The research findings demonstrate that the type of starch used has a significant impact on CMYK (cyan, magenta, yellow, key) colour quality in electrophotographic printing. According to the research results, potato starch performed better than other types of starch in terms of colour harmony, colour saturation, colour consistency, and colour difference. Tapioca and wheat starch were identified as the starch types yielding the worst results.

Structural rigidity in autonomous vehicle camera mounting: Critical determinant of perception system accuracy and safety

2025-06-24

Nikunjbhai Manilal Karoliya | World Journal of Advanced Engineering Technology and Sciences

This article examines the critical role of camera mounting systems in autonomous vehicles, analyzing their fundamental importance to perception reliability and vehicle safety. The article shows optimal camera placement strategies … This article examines the critical role of camera mounting systems in autonomous vehicles, analyzing their fundamental importance to perception reliability and vehicle safety. The article shows optimal camera placement strategies for achieving 360-degree environmental awareness through strategic field-of-view configurations and redundancy principles. It addresses the engineering challenges in structural mounting, including vibration isolation techniques, material selection considerations, and design parameters necessary for maintaining calibration integrity. The article quantifies the effects of mounting structural degradation on perception accuracy, demonstrating the relationship between mounting integrity and sensor fusion performance while documenting real-world failure cases. Environmental factors affecting camera mount performance are analyzed, including thermal expansion effects, vibration profiles across different road conditions, and weatherproofing requirements. Finally, the study explores emerging technologies in camera mounting systems, including active stabilization mechanisms, self-calibrating arrays, advanced composite materials, and integrated maintenance solutions that promise to enhance long-term system reliability.

Predicting the Responses in Color Matching Experiments From the Symmetries of Color Space

2025-06-23

Nicolás Vattuone , Inés Samengo | Color Research & Application

ABSTRACT In conceptual spaces, the distance between concepts is represented by a metric that cannot usually be expressed as a function of a few salient physical properties of the represented … ABSTRACT In conceptual spaces, the distance between concepts is represented by a metric that cannot usually be expressed as a function of a few salient physical properties of the represented items. For example, the space of colors can be endowed with a metric capturing the degree to which two chromatic stimuli are perceived as different. As many optical illusions have shown, the color with which a stimulus is perceived depends, among other contextual factors, on the chromaticity of its surround, an effect called “chromatic induction”. Heuristically, the surround pushes the color of the stimulus away from its own chromaticity, increasing the salience of the boundary. Previous studies have described how the magnitude of the push depends on the chromaticity of both the stimulus and the surround, concluding that the space of colors contains anisotropies and inhomogeneities. The importance of contextuality has cast doubt on the practical or predictive utility of perceptual metrics, beyond a mathematical curiosity. Here we provide evidence that the metric structure of the space of colors is indeed useful and has predictive power. By using a notion of distance between colors emerging from a subjective metric, we show that the anisotropies and inhomogeneities reported in previous studies can be eliminated. The resulting symmetry allows us to derive a universal curve for the average chromatic induction that contains no fitting parameters and is confirmed by experimental data. The theory also predicts the magnitude of chromatic induction for every possible combination of stimulus and surround, demonstrating that, at least in the case of colors, the metric captures the symmetries of perception and augments the predictive power of theories.

Prediction of Color Coordinates of Polyester Fabrics Dyed with Madder Using Mamdani-Fuzzy Logic and Optimization Algorithm

2025-06-21

Morteza Vadood , Aminoddin Hajı | Fibers and Polymers

Spectral Limit of the Optical Behavior Between Film and Substrate for a Fluorine-Doped Tin Oxide (FTO) Transparent Conductive Layer

2025-06-19

David Barrios-Puerto | Deleted Journal

The optical constants of a fluorine-doped tin oxide (FTO) transparent conductive layer (of 400 nm thickness), deposited over a glass (G) substrate, were determined from the collimated transmittance (T) and … The optical constants of a fluorine-doped tin oxide (FTO) transparent conductive layer (of 400 nm thickness), deposited over a glass (G) substrate, were determined from the collimated transmittance (T) and reflectance (R) optical measurements of a bilayer FTOG sample in the solar wavelength range (from 250 nm to 2500 nm). The three-extinction matching requirement (3εMR) phenomenon was used as a feedback system to validate the accuracy of the optical constants results, obtained by fitting to the collimated T and R solutions of the four-flux model (4FM). The same extinction coefficients (ε) were observed than the obtained when computing light fluxes at the interfaces and substituting into the 4FM collimated differential equations (CDE). The compression of the wavelength of the incident light inside G and FTO layers was validated by computing ε from optical constants. Despite a layer is considered a thin film when its thickness is lower than the wavelength of incident light beam, and a substrate when higher, the 3εMR allowed to determine the spectral limit of the FTO layer behavior, as a substrate and as a film, at 1200 nm (instead of at 400 nm, i.e., three times higher). FTO layer behaves as a substrate, for the shorter wavelength range of the solar spectrum (SWRSS), and as a film, for the longer wavelength range of the solar spectrum (LWRSS). The thickness gradients of the forward and backward (for&back) collimated light fluxes were determined at the glass substrate of the G and FTOG samples and for the SWRSS of the FTO as a substrate layer. Then, for the LWRSS, the thickness gradients for the complex magnitude and phase (Bode plots) of for&back electric fields of the FTO film layer have been spectrally determined and represented by means of imaginary versus real parts (Nyquist plots) depending on wavelength. Received: 12 February 2025 | Revised: 9 May 2025 | Accepted: 29 May 2025 Conflicts of Interest The author declares that he has no conflicts of interest to this work. Data Availability Statement Data sharing is not applicable to this article as no new data were created or analyzed in this study. Author Contribution Statement David Barrios-Puerto: Conceptualization, Methodology, Software, Validation, Formal analysis, Investigation, Resources, Data curation, Writing – original draft, Writing – review & editing, Visualization, Supervision, Project administration.

Image Processing Smart Glasses for Visually Impaired

2025-06-19

K. Kanchana , V. Srikanth Babu , S. Nithyasree | CRC Press eBooks

A Generic Model to Improve Color Reproduction Accuracy of Mobile Displays: A Case Study on Apple Devices

2025-06-19

Aurora Larrosa , Eric Kirchner , Esther Perales +3 more | Applied Sciences

Color visualization on websites and in apps usually tacitly assumes device-independent sRGB color space, bypassing the essential step of characterization—a process that requires expensive equipment and significant time. This work … Color visualization on websites and in apps usually tacitly assumes device-independent sRGB color space, bypassing the essential step of characterization—a process that requires expensive equipment and significant time. This work proposes a pseudo-device-independent approach applicable to Apple displays, one of the most renowned brands in this area, eliminating the need for characterization by leveraging the Mobile Display Characterization and Illumination Model (MDCIM). For this purpose, 11 Apple mobile displays were characterized, analyzing variations in parameters from spectroradiometer measurements and improving their sRGB tone rendering curves. Tested on an iPhone XS Max, the Color for the Average Apple Display model (CAAD) improved reasonable to good color matches from 4.0% to 84.3%, while incorrect matches dropped from 85.3% to 4.9% when compared to sRGB. These results are nearly as strong as those of the device-specific MDCIM, suggesting that an average model is a practical alternative to individual display characterization.

Directionality, Dimensionality, and Distortion

2025-06-19

O.P. Mishra , D.C. Naskar | CRC Press eBooks

Semitransparent perovskite solar panel with front spectral conversion glass for photovoltaic window application

2025-06-19

Pei Song , Chaomin Zhang , Pengfei Zhu | Journal of Photonics for Energy

Decolorization with Warmth–Coolness Adjustment in an Opponent and Complementary Color System

2025-06-18

Oscar Sanchez-Cesteros , M. Rincón | Journal of Imaging

Creating grayscale images from a color reality has been an inherent human practice since ancient times, but it became a technological challenge with the advent of the first black-and-white televisions … Creating grayscale images from a color reality has been an inherent human practice since ancient times, but it became a technological challenge with the advent of the first black-and-white televisions and digital image processing. Decolorization is a process that projects visual information from a three-dimensional feature space to a one-dimensional space, thus reducing the dimensionality of the image while minimizing the loss of information. To achieve this, various strategies have been developed, including the application of color channel weights and the analysis of local and global image contrast, but there is no universal solution. In this paper, we propose a bio-inspired approach that combines findings from neuroscience on the architecture of the visual system and color coding with evidence from studies in the psychology of art. The goal is to simplify the decolorization process and facilitate its control through color-related concepts that are easily understandable to humans. This new method organizes colors in a scale that links activity on the retina with a system of opponent and complementary channels, thus allowing the adjustment of the perception of warmth and coolness in the image. The results show an improvement in chromatic contrast, especially in the warmth and coolness categories, as well as an enhanced ability to preserve subtle contrasts, outperforming other approaches in the Ishihara test used in color blindness detection. In addition, the method offers a computational advantage by reducing the process through direct pixel-level operation.

Perceived Colorfulness of High‐Brightness Color Stimuli

2025-06-17

Yongmin Park , Michael J. Murdoch | Color Research & Application

ABSTRACT Perceived colorfulness (or color saturation) of a new high‐brightness color stimuli dataset was measured in a psychophysical scaling experiment. Stimuli created with a 7‐primary LED system covered a broad … ABSTRACT Perceived colorfulness (or color saturation) of a new high‐brightness color stimuli dataset was measured in a psychophysical scaling experiment. Stimuli created with a 7‐primary LED system covered a broad range of luminance from 50 to 2000 cd/m 3 and reached chromaticities beyond Rec. 2100. Experimental results reveal that previous color appearance models, such as CIECAM16 and CIELAB, do not accurately describe the measured colorfulness results, but predictions can be improved with simple power functions. Testing shows that applying a simple model results in statistically significant improvements in the performance of the predictors. This work will not only help understand the color perception of future HDR displays and advanced lighting system with narrow‐band primaries, but also contribute to future improvements to CAMs.

Colour map displays

2025-06-17

Nandita M. deSouza , Miha Fuderer , Nico Sollmann +2 more | Insights into Imaging

Evaluation of classic colour constancy algorithms on spectrally rendered ground-truth

2025-06-16

Matteo Toscani , Tao Chen , Giuseppe Claudio Guarnera | Perception

The limited availability of spectral images poses a significant challenge to the field of colour science. To address this issue, we spectrally rendered naturalistic images, enabling us to investigate the … The limited availability of spectral images poses a significant challenge to the field of colour science. To address this issue, we spectrally rendered naturalistic images, enabling us to investigate the performance of classic colour constancy algorithms, including Grey-World , White-Patch , Grey-Edge , Shades-of-Grey , and Gamut-Mapping . We generated 4,096 physically based rendered scenes under different coloured illuminations, including a spectrally neutral illumination. We evaluated each algorithm by (1) comparing the illuminant estimated by the algorithm with the actual illuminant used for rendering and (2) assessing the performance based on the entire scene rendered under the neutral illuminant. The White-Patch algorithm consistently performed relatively well, while Gamut-Mapping emerged as the top-performing algorithm when evaluating the whole scene. However, it exhibited poor performance in estimating the ground-truth illuminant. We conducted a perceptual experiment to measure human colour constancy across a representative selection of scenes from our database using an asymmetric colour matching task. The results indicated that predictions from the algorithms that performed best when evaluated on the whole scene – white patch and gamut mapping – best approximate human performance. Indeed, the function of colour constancy is to stabilise the colour of all surfaces in a scene, rather than to estimate the colour of the illumination.

Chromaticity Space Uniformity and Gamut: Analysis and Visualization

2025-06-15

Kenichiro Masaoka | Journal of the Society for Information Display

ABSTRACT The perceptual uniformity of the CIE 1931 ( x , y ) and CIE 1976 ( u' , v' ) chromaticity spaces is examined using the latest color difference … ABSTRACT The perceptual uniformity of the CIE 1931 ( x , y ) and CIE 1976 ( u' , v' ) chromaticity spaces is examined using the latest color difference metric. A honeycomb sampling method reveals that the u'v' space is less uniform than the xy space, highlighting the need to abandon the u'v' space and adopt gamut rings for color gamut visualization.

Dynamic Structural Colors in Cholesteric Cellulose Composites: Achieving Spatial and Temporal Control

2025-06-14

Simona G. Fine , Chenyu Guo , Cécile A. C. Chazot | Advanced Optical Materials

Abstract Structurally‐colored cholesteric cellulose ether materials offer a sustainable alternative to traditionally‐dyed plastics. These materials are produced by dissolving high concentrations of cellulosic polymers in a monomeric solvent, forming a … Abstract Structurally‐colored cholesteric cellulose ether materials offer a sustainable alternative to traditionally‐dyed plastics. These materials are produced by dissolving high concentrations of cellulosic polymers in a monomeric solvent, forming a liquid crystalline mesophase, and polymerizing to kinetically trap the ordered arrangement in a composite. Despite significant advancements in fabricating colorimetric films and devices using this method, the lack of critical design rules for predicting color evolution upon polymerization hinders large‐scale deployment and rational design. In this work, ethyl cellulose‐poly(acrylic acid) films are used as a model system to explore how the balance between polymer chain mobility and solvent photopolymerization kinetics affect the preservation of cholesteric texture and optical properties. These findings reveal that the observed blue‐shift in reflectivity is linked to the realignment or disruption of chiral nematic order during poly(acrylic acid) chain growth. Time‐resolved studies during UV curing, including in situ reflection spectroscopy and rheometry, demonstrate that rapid polymerization and reduced polysaccharide mobility are key to maintaining the color and angle‐dependent optical appearance in the final films. Applying these fundamental design principles, we create composites with spatially‐controlled photopatterned colors, tailored angle‐resolved reflectivity that resists photobleaching, and reversible colorimetric functions that are unattainable with pigmented plastics.

Characteristic Line Rendering Method of Ink Painting Based on Adaptive Multiscale Morphological Filtering

2025-06-13

Zengyu Liu , Yingchao Zhao | International Journal of High Speed Electronics and Systems

This paper introduces an innovative technique to render different traces located in ink artwork, leveraging adaptive multiscale morphological filtering generation. Ink portray, a traditional Oriental artwork form, is renowned for … This paper introduces an innovative technique to render different traces located in ink artwork, leveraging adaptive multiscale morphological filtering generation. Ink portray, a traditional Oriental artwork form, is renowned for its precise expression via traces and the use of ink. Within the realm of digitization, authentically reproducing these unique progressive elements poses a huge undertaking. Our approach goals to faithfully simulate ink portray’s line tendencies while retaining its revolutionary appeal and cultural importance, using device studying and image processing strategies. We display the efficacy of our technique in rendering numerous types of ink-drawn lines. The results exhibit that our method adeptly replicates the street fashion determined in conventional ink portray. Furthermore, it complements the creative expression of virtual ink portray at the equal time as retaining a high degree of visible authenticity. The adaptable nature of our technique renders it appropriate for numerous creative patterns and varied software situations. This research not only charts a powerful technical pathway for digitally rendering ink artwork but also offers an easy mind-set on amalgamating traditional artwork with modern era. It is predicted to make a widespread impact within the geographical areas of resourceful advent and cultural data maintenance.

Correction: Recent progress in printable structural colors

2025-06-13

Huan Xiao , Johnny Austin Lomas , Ying Diao | MRS Communications

An infinite spectrum of colours 2

2025-06-09

Arianna Vergari , M. Elena D’Amelio , V. Re +1 more | Academic Quarter | Akademisk kvarter

This text outlines and contextualizes the methodological and stylistic choices underpinning the video essay An Infinite Spectrum of Colours. Teaching Gender Issues Through Prisma, whose theoretical implications are further developed … This text outlines and contextualizes the methodological and stylistic choices underpinning the video essay An Infinite Spectrum of Colours. Teaching Gender Issues Through Prisma, whose theoretical implications are further developed in the homonymous essay included in this special issue. Focusing on the representation of coming out in the television series Prisma (Amazon Prime Video, 2022-2024), it discusses the montage strategies, aesthetic decisions, and intertextual references employed to construct a critical and pedagogical discourse on non-binary and fluid gender identities. By embracing the video essay as a form of cinécriture, the text reflects on its potential as a tool for research, teaching, and media education—capable of combining analytical rigor with emotional engagement.

An infinite spectrum of colours 1

2025-06-09

Arianna Vergari , M. Elena D’Amelio , V. Re +1 more | Academic Quarter | Akademisk kvarter

This article presents the research underpinning the video essay An Infinite Spectrum of Colours: Teaching Gender Issues through Prisma (also included in this special issue) and aims to explore the … This article presents the research underpinning the video essay An Infinite Spectrum of Colours: Teaching Gender Issues through Prisma (also included in this special issue) and aims to explore the value of serial dramas as tools for discussing gender issues and enhancing media literacy in high school students. Through interviews with industry professionals, textual analysis and analysis of promotional materials, this work explores Prisma (2022-2024), an Italian coming-of-age series co-produced by Amazon Prime Video and Cross Productions. Prisma builds on the “SKAM methodology,” which includes in-depth research, youth interviews, and consultant advice to engage viewers with authentic narratives around gender, identity, inclusivity, and disability. Its thoughtful and educational approach to gender-related topics makes it a valuable case study. In particular, the article focuses on the “coming out” theme, examining it through three lenses: a) narrative techniques that challenge stereotypes by subverting the viewers’ expectations; b) media literacy, comparing coming out scenes from other series; and c) gender insights, exploring how this theme resonates with non-binary and fluid identities.

Evaluating Color Spaces for Evolutionary Image Contrast Enhancement: An Empirical Study

2025-06-08

Rafael Solar-Hernández , Saúl Zapotecas–Martínez , Leopoldo Altamirano-Robles +2 more | 2022 IEEE Congress on Evolutionary Computation (CEC)

COLOR PLATE CREDITS

2025-06-03

| Princeton University Press eBooks

Pelican Optimization based Histogram Equalization for Contrast Enhancement and Brightness Preservation

2025-06-02

Niveditta Thakur , Nafis Uddin Khan , Sunil Sharma +1 more | International Journal of Image Graphics and Signal Processing

Improved image display by identifying the RGB family color space

2025-06-01

Elvis Togban , Djemel Ziou | Displays

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Comparative Study on Monolithic Zirconia and Lithium Disilicate

2025-06-01

A. S. Patil , Manish Bhise , Shivsharan B. Dhadde +3 more | Journal of Pharmacy And Bioallied Sciences

A BSTRACT Background: In recent years, patient awareness and demands for dental aesthetic have increased tremendously. Aim: To compare between MZ and DL for SR and CR. Material and Method: … A BSTRACT Background: In recent years, patient awareness and demands for dental aesthetic have increased tremendously. Aim: To compare between MZ and DL for SR and CR. Material and Method: A total of 64 samples were included and divided into two groups, i.e. A and B. Result: Significant difference in LD for SR and CS for MZ and LD while nonsignificant for MZ for SR. Conclusion: Minimum change in CS and SR was shown by 0.1% CD in both MZ and LD groups.

Study of color mixing by amplitude modulation driving technique of an RGB LED

2025-05-30

A. Simon , Árpád Mike , A. Tunyagi | Romanian Reports in Physics

In this paper the possibilities of additive color mixing are studied using a single RGB LED driven by the amplitude modulation technique. In order to approach the color mixing in … In this paper the possibilities of additive color mixing are studied using a single RGB LED driven by the amplitude modulation technique. In order to approach the color mixing in a more pedagogical way, the LED is characterized from both electrical and spectral point of views, then several mixing scenarios are established and critically tested.

Integration of Internal Structure in Ink Figure Painting

2025-05-30

Weiping Zeng , Jianlan Zeng | Journal of Education and Educational Research

This paper explores the internal structural integration of ink figure painting, with a particular focus on freehand depictions of ethnic minority figures. It analyzes the organic fusion of compositional language, … This paper explores the internal structural integration of ink figure painting, with a particular focus on freehand depictions of ethnic minority figures. It analyzes the organic fusion of compositional language, modeling language, brush-ink language, and personal language. By comparing compositional concepts from both Chinese and Western traditions—where traditional Chinese painting emphasizes artistic conception and scattered perspective, while Western painting prioritizes linear perspective—the study examines how modeling training and innovations in brush and ink facilitate mutual influence. Flexible compositional language can break away from outdated symmetrical or centered patterns, enabling open spatial structures and expressive brushwork that contribute to the development of personal style. The innovation of this research lies in its systematic articulation of the compositional mechanisms in ethnic minority freehand figure painting, highlighting the critical role of integrating traditional ink painting elements with personal language, thereby offering a new perspective for related theoretical exploration.

The Seven Types of Frieze Patterns

2025-05-28

John H. Conway , Heidi Burgiel , Chaim Goodman-Strauss | A K Peters/CRC Press eBooks

Yarn Formation Mechanism and Application of Rotor Spinning Wide-Color Gamut-Blended Yarn for Ostwald Color Solid

2025-05-27

Jinjian Li , Yuan Xue , Yourong Chen +2 more | Journal of Natural Fibers

Photochromic Sensors for Paper Marking

2025-05-26

Elżbieta Sąsiadek , Malwina Jaszczak , Mariusz Dudek +2 more

This study presents UV radiation sensors for use as paper marking. The sensors turn pink under exposure to UVA radiation and the color change is reversible. Additionally, a UV radiation … This study presents UV radiation sensors for use as paper marking. The sensors turn pink under exposure to UVA radiation and the color change is reversible. Additionally, a UV radiation retarder was applied to the sensor to delay the reaction and weaken the change in sensor color. The color changes of the sensors were analyzed depending on the absorbed dose of UVA radiation using reflectance spectrophotometry. Furthermore, the chemical analysis and surface morphology of the samples were performed using Raman Spectroscopy and Scanning Electron Microscopy, respectively. In addition, the structure of the sensors on the paper surface was assessed using X-ray Micro-Computed Tomography. Finally, possible potential applications for these types of sensors were presented, including marking, securing, and protecting against the counterfeiting of documents, paper packaging, and other paper products, and creating decorative elements, as well as measuring the 2D/3D dose distribution of UV radiation on paper products.

Bilayer Smart and Multifunctional Camouflage Textiles Integrating Adaptive Visible Stealth, Infrared Concealment, and Electromagnetic Interference Shielding

2025-05-25

Pan Yao , Xiangning Hu , Changhuai Ye +1 more

Analysis of the Structural and Photophysical Properties of Dyes

2025-05-23

Ms. Kritika , Sudhir Kumar Pathak , S. K. Kaushik | International Journal For Multidisciplinary Research

Dyes and pigments have the power to make the world a more beautiful place. With a long history of use, they have diverse applications in various industries, including food, textiles, … Dyes and pigments have the power to make the world a more beautiful place. With a long history of use, they have diverse applications in various industries, including food, textiles, artifacts, and paper. This has led to extensive research on developing natural colorants from natural sources. The benefits of using natural colorants are numerous. They are eco-friendly, safe, and easily obtained from renewable sources. Natural colorants are also soft, lustrous, and soothing to the human eye. Additionally, they do not pose health hazards and offer no disposal problems. India is a rich source of natural colorants, with an estimated 500 varieties of colorant-producing plants. This mini-review explores fundamental aspects of colorants, including their classification, chemical constituents, newer methods of production and extraction, and prospects. Furthermore, coumarin and its derivatives have emerged as versatile compounds with various biological and pharmacological applications, including anti-inflammatory, antifungal, and antibacterial properties. This review highlights the use of coumarin derivatives as dyes and their impacts on the environment and human health.

Harmonic classification of different lighting technologies using empirical mode decomposition and support vector machines

2025-05-23

Ahmad Farid Abidin , Mohd Abdul Talib Mat Yusoh , Abdul Hafiz Kassim +1 more | TURKISH JOURNAL OF ELECTRICAL ENGINEERING & COMPUTER SCIENCES

The Geometry of Color in the Light of a Non‐Riemannian Space

2025-05-23

Roxana Bujack , Emily S. Teti , Terece L. Turton +2 more

Abstract We formalize Schrödinger's definitions of hue, saturation, and lightness, building on the foundational idea from Helmholtz that these perceptual attributes can be derived solely from the perceptual metric. We … Abstract We formalize Schrödinger's definitions of hue, saturation, and lightness, building on the foundational idea from Helmholtz that these perceptual attributes can be derived solely from the perceptual metric. We identify three shortcomings in Schrödinger's approach and propose solutions to them. First, to encompass the Bezold‐Brücke effect, we replace the straight‐line definition of stimulus quality between a color and black with the geodesic path in perceptual color space. Second, to model diminishing returns in color perception, we employ a non‐Riemannian perceptual metric, which introduces a potential ambiguity in defining lightness, but our experiments show that this ambiguity is inconsequential. Third, we provide a geometric definition of the neutral axis as the closest color to black within each equal‐lightness surface—a definition feasible only in a non‐Riemannian framework. Collectively, our solutions provide the first comprehensive realization of Helmholtz's vision: formal geometric definitions of hue, saturation, and lightness derived entirely from the metric of perceptual similarity, without reliance on external constructs.