bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determining dimensioned values of kubelka–munk scattering and absorption coefficients
Authors: Marcus Robert T. 
Published: June 2007

AbstractIf hiding computations are to be made in conjunction with computer color matching, the Kubelka–Munk absorption and scattering coefficients, K and S, must be dimensioned (absolute) coefficients. Two procedures for calculating the dimensioned coefficients were compared. In the first, the coefficients were calculated directly by two different methods from films applied at incomplete hiding over white and black substrates. In the second, previously calculated dimensioned coefficients for titanium dioxide formed the basis of determining the coefficients for the remaining pigments from films applied at complete hiding. Experimental results showed the second procedure superior to either method of the first procedure, except for determining dimensioned K and S for titanium dioxide.
The chemistry behind the artist's palette
Authors: Orna Mary Virginia 
Published: June 2007

AbstractThe origin of color in organic and inorganic artists' pigments is discussed and, where possible, is related to their physical properties such as lightfastness and brilliance. Included in the discussion are the nature of color, the types of chemical species that exhibit color, and the structural features of these compounds that make them colored. The compounds are categorized according to the structural properties that enable them to absorb visible radiation.
Proposal for an empirical approach to color reproduction
Authors: Rhodes Warren L. 
Published: June 2007

AbstractThis article is a review of conventional approaches to color transformations between originals and reproductions, and it explores new methods and transformations made possible by point‐by‐point scanning. “Color correction” has traditionally been based on colorimetric matching between an original and its reproduction. “Corrections” have been based either on additivity and proportionality laws or on Neugebauer's equations which assume additivity of tristimulus values. These approaches were appropriate because photographic masking and early color scanners had to rely on analog methods. Digital methods were too slow. Digital processing speeds may have increased enough to allow point‐by‐point processing of the 2 X 107 points scanned in an 8 in X 10 in. original. Several workers have proposed transformations which are not colorimetric matches. Their experiments have been constrained by the need for analog processing and by conventional process characteristics. By using point‐by‐point table lookup, any transformation, including spatial as well as colorimetric, is possible. It will be interesting to study color reproduction using this new tool.
Reply to ohta–wyszecki on location of nodes of metameric stimuli
Authors: Thornton W. A. 
Published: June 2007

AbstractThe simplest spectral‐power distributions of lights which match to a human observer intersect in three specific wavelength bands near 448, 537, and 612 nm. Simple lights which match to a detector intersect near the wavelength of peak spectral response of that detector. By analogy, the three specific wavelength bands must mark the peaks of spectral response of the normal human visual system. More complex spectral‐power distributions of matching lights may mask the relation between intersection behavior and visual system response.
Properties of standard materials for reflection
Authors: Erb W. , Budde W. 
Published: June 2007

AbstractThis article gives a short survey of some literature on the calibration, suitability, properties, and use of various materials which are used as standards of reflectance. The classical ultimate reference standard, smoked magnesium oxide, is discussed briefly, and information is given on the properties of materials presently used: BaSO4, Russian opal glasses, ceramic tiles, and Halon.Halon is a registered trade name of the Allied Chemical Corporation.
The suitability of these materials for use as transfer standards or working standards is discussed.
Changes in color appearance with variations in chromatic adaptation
Authors: Bartleson C. J. 
Published: June 2007

AbstractChromatic adaptation has been studied by applying methods of direct scaling to color appearances of invariant stimuli seen under different conditions of adaptation. The influence on color appearance of correlated color temperature of illumination, sample luminance factor, illuminance, and surround induction was studied. Perceived hue [expressed as proportions of unitary hues] varies with color temperature of illumination but not significantly with luminance factor or illuminance for the conditions of these experiments. Colorfulness varies with color temperature and also with luminance factor and illuminance, although relative colorfulness does not change significantly with illuminance. Lightness varies with luminance factor but is essentially independent of color temperature and illuminance over the ranges investigated here. Achromatic and chromatic lightnesses for samples of equal luminance differ in systematic ways that depend upon dominant wavelength and excitation purity. Color appearance data for daylight adaptation are highly correlated with Munsell Renotation specifications. The results may be used to determine corresponding colors for the adaptation conditions studied [equivalent to CIE Illuminants D65, D50, A, and dark adaptation]. They may also be used to determine color appearances under those conditions throughout a color solid. It is anticipated that they will be used as the basis for developing mathematical expressions for predictions of corresponding colors under other illumination conditions as well.
Predicting corresponding colors with changes in adaptation
Authors: Bartleson C. J. 
Published: June 2007

AbstractA method is proposed for determining chromaticity coordinates of stimuli that elicit the same colors over changes in chromatic adaptation. The method uses equations derived from a recent study of the influence of chromatic adaptation on color appearance. A single set of König‐type fundamental primaries is used, and the “red” and “green” fundamentals are altered by changes in adaptation according to a coefficient rule while, in addition, the “blue” fundamental is modified through a power transform. No ulterior information is required beyond a knowledge of the chromaticities of samples and illuminants. The method agrees well with the experimental data from which it was derived, with predictions from a number of other transformation methods, and with raw data from five independent studies of chromatic adaptation. The method thus offers utility and a reasonable compromise between generality and simplicity on the one hand and accuracy on the other.
Cube‐Root Color Spaces and Chromatic Adaptation
Authors: Richter Klaus 
Published: June 2007

AbstractThe recommendations of the International Commission on Illumination (CIE) on the CIELUV 1976 and CIELAB 1976 color spaces are discussed. A cube‐root chromaticity diagram (a',b') for CIELAB 1976 is added. A slightly modified cube‐root chromaticity diagram (A',B') is proposed which takes care of the CIE corrections (1978) for saturated yellow and red colors in CIELAB 1976 color space. Important advantages of the corresponding cube‐root color space labeled LABHNU 1977 are shown and compared to the CIELUV 1976 and CIELAB 1976 color spaces. Chromatic adaptation can be described approximately as an equal (cube‐root) chromaticity shift for all test colors defined by the two chromaticities of the adaptation illuminants. These properties are discussed and compared to our own chromatic‐adaptation data and data published by Bartleson (1978). Color‐appearance attributes and differences are studied for CIE standard illuminants D65 and A. The Munsell data and OSA data and the main properties of different experiments of Evans and Swenholt (1968) and Pointer (1974) lead to the LABHNU 1977 color space which is evaluated for chromatic adaptation to different illuminants and is compared to the CIELAB 1976 and CIELUV 1976 color spaces.
Evaluation of Different Color‐Difference Formulae by Means of an Experiment on Color Scaling: Final Report
Authors: Lozano Roberto D. 
Published: June 2007

AbstractEleven color‐difference formulae were tested for medium and large color differences in a psychophysical experiment on color scaling. A preliminary report has been published and one more formula has been added since then. A third experiment is included in this report dealing with variations of the field size and background. The results were tested statistically for conformance to three different types of mathematical law (linear, exponential, and potential) and with a few exceptions, linear approximation showed the higher regression coefficient. For color differences as large as 17 ± 11 CIELAB units, this experiment suggests that the CIELAB formula is a good recommendation, but it is no better than the new proposal of Richter or the well‐known cube root and Adams‐Nickerson formulae.
A Color Metric from Opponent‐Color Visual Channels
Authors: Rich Danny C. 
Published: June 2007

AbstractA Euclidean metric for colorimetric evaluations based on an opponent‐color system was described by Ingling and Tsou. The metric was shown to work well for predicting the results of the standard color‐discrimination experiment. The metric is applied to the surface‐color data of the Munsell collection, the Morley, Munn, and Billmeyer data, and the data from the ISCC Committee on Color Difference Problems.
Color Differences Caused by Dye Weighing Errors
Authors: Stanziola Ralph 
Published: June 2007

AbstractThis is the first in a series of short communications which we believe will be of immediate practical use to industrial colorists in applying color technology to their daily work. The series is edited by Ralph Stanziola, who replaces James G. Davidson as Special Editor for Industrial Applications at this time. Dr. Davidson now becomes a regular member of our Editorial Board.Readers who wish to contribute ideas for future Industrial Notes are encouraged to contact Mr. Stanziola at the address given next to the Table of Contents—F.W.B.
Calculation of the Spectral Radiance Factors of Luminescent Samples
Authors: Billmeyer Fred W. , Chong Tak‐Fu 
Published: June 2007

AbstractIt is often desirable to calculate the spectral radiance factor (SRF, the sum of the reflected and fluorescent radiances) which a photoluminescent—commonly called a fluorescent—sample would exhibit if it were irradiated by a standard illuminant, such as CIE D65, which is not available as a source for direct measurement. Several methods described in the literature for calculating the desired SRF from measurements made using available sources are tested experimentally using measurements made on commonly available one‐monochromator integrating‐sphere spectrophotometers. The choice of the calculation method is shown to be less important than the closeness of the match of the spectral distribution of irradiance on the sample to that from the standard illuminant. This is influenced by both the selection of the experimental source and the effects of the integrating sphere. With all variables properly controlled, comparison of calculated and directly measured SRFs leads to color differences less than one CIELAB unit.
Three are Not Enough: An INDSCAL Analysis Suggesting that Color Space Has Seven (£1) Dimensions
Authors: Chang J. J. , Carroll J. D. 
Published: June 2007

AbstractForty‐five subjects, including color normals, protanomalous, deuteranomalous, protanopes, and deuteranopes, judged dissimilarities of 26 Munsell color chips chosen to span the full color space (i.e., all three parameters—hue, saturation, and lightness—were varied). Each of the 325 pairs of colors was mounted on a standard grey background board. They were presented to subjects in different random orders and were viewed under a Macbeth daylight lamp. For each pair the subject circled a number varying from 0 (for “identical”) to 9 (for “maximally dissimilar”). Fifty data matrices obtained from 45 subjects (5 were from the same subject on different dates and 2 were from another subject) were analyzed by the INDSCAL method. The three‐dimensional solution yielded the “standard” three dimensions (lightness, red‐green, and yellow‐blue) with the classical “color circle” emerging, in a slightly distorted form, in the plane of the second and third dimensions. Seven dimensions seemed necessary to account fully for these data, however. In seven dimensions each of the “standard” dimensions is paired with a “folded” version. Accompanying lightness is a “folded” lightness dimensions, which we have called “lightness contrast.” The light and dark colors are at one end, contrasted with medium colors at the other. Similarly, “folded” red‐green roughly contrasts red and green with blue, yellow, and the greys, while “folded” yellow‐blue contrasts blue and yellow with red, green, and the greys. The seventh dimension, which may be artifactual, was called “split yellow.” It contrasts very brilliant (high Munsell value and chroma) yellow and orange colors with all the other colors. It is speculated that some of these extra dimensions may relate to anomalous receptor processes characteristic of deviant subjects. The INDSCAL subject space enables discrimination among all five subject types. Specifically, one of the “natural planes” (the red‐green versus “folded” yellow‐blue plane) of the seven‐dimensional solution can be divided into contiguous and fairly compact regions, with each subject type occupying a unique region.
Colour‐Rendering Assessment of Ultraviolet Emission in Light Sources
Authors: Henderson S. T. , Halstead Margaret B. 
Published: June 2007

AbstractA number of different ways for the assessment of the ultraviolet emission of light sources are surveyed. A method of assessment using a set of three hypothetical near‐white fluorescent samples is described in which the sum of the excitation curves for the fluorescent samples has been made to resemble the spectral emission curve of Standard Illuminant D65 when plotted on a quantum scale of ordinates. The chromaticity shift of each fluorescent sample produced when the reference illuminant D65 is replaced by the test illuminant is used to produce a special fluorescent‐rendering index in a manner analogous to that used for colour‐rendering indices. The index is scaled in such a way that values greater than 100 indicate an excess of ultraviolet for the test lamp compared with the reference illuminant. Special fluorescent‐rendering indices are given for a number of real lamps, and they accord reasonably well with the known performance of the lamps.
Formulations for the OSA uniform color scales committee samples
Authors: Davidson Hugh R. 
Published: June 2007

AbstractPigment formulations used in producing the 558 samples illustrating the OSA Uniform Color Scales Committee color space are presented. The 15 pigments used, never more than four at a time, are identified and calibration data for computer formulation are given. The information should allow the reproduction of close approximations to the original OSA samples.
Color scales in simulated daylight
Authors: Macadam David L. 
Published: June 2007

AbstractThe pigmentation plan used for production of the color cards made available by the Optical Society of America (OSA) for its Committee on Uniform Color Scales (UCS) was designed in such a manner that the color scales should, within the production tolerances, appear uniform in all phases of daylight. The production specifications were based on D65 of the Commission International de L'Eclairage (CIE) and the CIE supplementary observer (1964) for 10° visual‐field subtense. To test for the intended invariance of uniformity of the scales in daylight, for normal observers, the effects on color differences between all nearest neighbors of the OSA colors have been studied for CIE Illuminant C with the 1931 observer, and for a “daylight” fluorescent luminaire (color temperature 6500 K) with both the 1931 and 1964 CIE observers. Although the colorimetric specifications (Y, x, y) of each color card are different for those three illuminant + observer combinations, the color differences computed with the formula of the OSA‐UCS committee are, within the production tolerances, unchanged. The purpose of this article is to show how well the aim and expectation is fulfilled—that the uniformity of color differences between nearest neighbors in the scales of the OSA‐UCS colors be essentially unchanged for normal observers and for ordinary variations of the quality of natural and artificial daylight. This invariance is found, even for daylight‐quality fluorescent‐lamp light.
Low‐Reflectance Backing Materials for Use in Optical Radiation Measurements
Authors: Wightman T. E. , Grum F. 
Published: June 2007

AbstractMaterials having a very low reflectance over a large spectral region are necessary for many scientific application, especially in aerospace, spectrophotometry, spectroradiometry, and photography. This article surveys black absorbing materials and devices being used throughout the industry. Also described is a new black backing device with reflectances of less than 0.1% i.e., 99.9% absorptance, that can be used as a sample backing and for determining the zero photometric scale in spectrophotometry and photometry. The reflectance of the device is nearly perfectly flat between 0.200 and 2.5 μm.
On Chromatic Adaptation and Persistence
Authors: Bartleson C. J. 
Published: June 2007

AbstractPersistence or invariance over changes in adaptation is examined for color matches, near‐threshold color differences, and large color differences. Persistence is usually thought to obtain for matches involving equiluminance samples under restricted but broadly useful conditions. Both small and large color differences vary over chromatic adaptation. Small differences vary less than large differences and both vary more with widely disparate conditions of adaptation than when adaptations are similar. A consequence of this finding is that color‐difference equations relate strictly to only one condition of adaptation. A corollary is that no single uniform‐chromaticity diagram can be expected to display color differences properly for different conditions of adaptation, although a uniform‐perceptual diagram could do so. What is needed to resolve the problem is an accurate method of chromatic‐adaptation transformations.
The Determination of Weights for Use in Calculating Tristimulus Values
Authors: Stearns E. I. 
Published: June 2007

AbstractMultiplication of weights by spectral radiance factors and summation is the usual method of calculating tristimulus values. The spectral‐radiance‐factor data may vary in abridgement (omission of intermediate data), truncation (omission of data at the extremes of the visual range), and in the case of fluorescent‐lamp illuminants, omission of mercury‐line data. This article sets forth recommendations for the calculation of weights for any set of spectral‐radiance‐factor data.
The future of color science
Authors: Robertson Alan R. 
Published: June 2007

AbstractColor science is a unique and stimulating blend of many scientific disciplines. Physicists, physiologists, psychologists, psychophysicists, mathematicians, and chemists have all contributed to our understanding of how we see color. Tools and techniques have been developed to help those who work with color in their everyday lives, whether it be in manufacturing, in design, in communication, or in any other field. Some tools, such as the CIE Standard Observer, were derived from empirical color‐matching data but can now be explained, at least approximately, on the basis of our knowledge of the physiology of the visual system. Others, such as most color‐difference formulae, are still purely empirical and explanations in terms of the actual functioning of the human visual system are largely unknown. It is likely that improved tools and techniques will come in the future as we increase our knowledge of the visual system and how it works. Such increased knowledge will come most readily if there is more cooperation between the various disciplines and less tendency to think along narrow discipline‐limited lines.
Practical transformations of CIE color‐matching functions
Authors: Ohta Noboru 
Published: June 2007

AbstractBy using the CIE color‐matching functions, we describe a numerical method to derive new color‐matching functions C(Λ) which satisfy the conditions (1) C(Λ) ≥ 0, (2) C(Λ) with a single peak, and (3) C(Λ)'s with the least overlaps.
On the merits of model making in understanding color‐vision phenomena
Authors: Vos J. J. 
Published: June 2007

AbstractSince 1962, I have intermittently been engaged in problems of color‐vision modeling, intrigued by some apparent inconsistencies in the original Walraven color‐vision model. This has carried me into problems of receptor action spectra and densities, of gain control and chromatic adaptation, and of the concept of luminance as a linear or nonlinear combination of receptor inputs. By taking a simple physical model as a start and adding physiological elements whenever the quantitative predictions failed, we hope to have gained some insight into the color‐vision mechanisms. This review is intended to enable a discussion of the limitations and merits of this rather theoretical approach.
Analysis of colour‐appearance grids and chromatic‐adaptation transforms
Authors: Pointer M. R. 
Published: June 2007

AbstractTen pairs of colour‐appearance grids, some derived experimentally and some theoretically, have been analysed using 18 sets of scaled data. The hue and colourfulness of the scaled data are compared with those values predicted by the grids. The results of the analysis suggest that Munsell Renotation data (for Munsell Value 5) can provide an adequate grid of loci of constant hue and colourfulness from which other grids, for other illuminants, can be derived. The results also support the suggestion that two types of grid are necessary to predict some data satisfactorily, depending on how those data were derived.
Color‐matching performance of polypropylene producers
Authors: Longley William V. 
Published: June 2007

AbstractProducers of colored injection‐molded polypropylene plastic parts for automotive interior use were assessed for color‐matching performance on the basis of calculated color difference, spectrophotometric similarity to the standard (freedom from metamerism), and visual color match. Considerable disparity was found among the efforts of the nine producers participating in the study.
Recent results from single‐cell microspectrophotometry: Cone pigments in frog, fish, and monkey
Authors: Hárosi Ferenc I. 
Published: June 2007

AbstractA modified design of a previous microspectrophotometer (DMSP) is described that utilizes a phase‐modulated light beam. Applied to rod and cone outer segments, it can simultaneously measure optical density (OD) and linear dichroism (LD) spectra. LD spectra were found to be largely unaffected by the presence of light scattering and the absorption of the less anisotropic photoproducts. The bullfrog was found to have blue‐absorbing cones in addition to other previously known photoreceptors in amphibians. Four visual pigments of the sea raven are described. Preliminary data are presented on the four pigments in rhesus and cynomolgus monkeys.
Color information coding of horizontal‐cell responses in fish retina
Authors: Fukurotani Kenkichi 
Published: June 2007

AbstractRetinal horizontal cells responded linearly to weak monochromatic lights. Their spectral responses were analyzed in the linear range. Mutually orthogonal relations were found among the three different types of spectral response curves. According to communication theory, the interactions between cones and horizontal cells are interpreted as an orthogonalizing process which provides the optimal coding for the transmission of color information to the central nervous system.