bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chromatic Difference Steps of Moderate Size Measured along Theoretically Critical Axes
Authors: Boynton Robert M. , Kambe Naotake 
Published: June 2007

AbstractA new method of measuring chromatic discrimination steps is described where observers must indicate in which direction a change has occurred, as well as the fact of its occurrence. This procedure seems to stabilize the subject's criterion of difference and yields step sizes more akin to those of Wright's “dashes” than MacAdam's ellipses. Tests have been made along two critical dimensions of variation: (1) the tritan axis, where discriminations depend initially only on variations in blue‐cone (B) excitation and (2) the red‐green axis, where discriminations depend on the substitution of red‐cone (R) excitation for that of green cones (G), or vice versa. Discriminations dependent on blue cones are affected by the level of B‐cone excitation but are independent of R/G. After individual differences are taken into account by a simple scaling factor, an equation of the form ΔB/ B + Bo = K accounts well for the data. Blue‐cone discrimination is found to be independent of the ratio of red‐to‐green‐cone excitation, with an optimal Weber fraction of about 18%. Discriminations dependent on the exchange of red‐and green‐cone excitation yield an optimal Weber fraction of about 2%. This ratio is increased, though not greatly, by an imbalance of the red‐green ratio relative to a neutral condition, and by increasing the level of blue‐cone excitation. At 120 td, the ratio between a MacAdam step and ours is approximately constant at about 13:1.
The Color Rule: A Device for Color‐Vision Testing
Authors: Kaiser Peter K. , Hemmendinger Henry 
Published: June 2007

AbstractThe D & H Color Rule, available since 1967, is useful as a color‐vision test and to check on the specification of secondary standard illuminants. The data of several authors are combined for ready availability as a diagnostic aid. Normal trichromats make responses with the Color Rule that are dependent on age. The apparent yellowing of the lens results in the same change in responses on the Color Rule as by an illuminant change of 50–75 MK−1.
Evaluation of Automotive Color Matches
Authors: Longley William V. 
Published: June 2007

AbstractSuppliers of color‐matched automotive parts are sometimes frustrated when match tolerances set by automotive stylists seem inconsistent or unrealistic. The stylist, on the other hand, sees a perplexingly wide range of quality and is aware of vast differences in expertise among those supplying material or parts. Here we explore the parameters affecting color match and discuss the role of color measurement in facing the problems.
OSA uniform color scale samples: A unique set
Authors: Nickerson Dorothy 
Published: June 2007

AbstractThe Optical Society of America, in early 1977, published a set of uniformly scaled coor samples based on specifications developed after long years of study by its Committee on Uniform Color Scales. The model for arranging and specifying the samples is based on an octahedral unit which consists of a cluster of 12 colors equally different from a central color and from each of its nearest neighbors. This space lattice, extended to accommodate all samples that can be produced within the gamut of present‐day colorants, is described, together with the adopted system of notation. The lattice provides three sets of square grids and four sets of triangular grids that correspond to the seven pairs of parallel faces of a cuboctahedron. Horizontal, vertical, and oblique cleavage planes through the lattice are described and illustrated. The OSA‐UCS set consists of 558 samples: 424 represent a regular 2‐unit sampling of OSA‐UCS committee space; 134 additional samples are provided in the much used, near‐neutral, central‐lightness region of color space. The set is unique because each sample in the regular set is represented in six different uniform color scales. These appear as linear arrays that pass in six different directions through each sample. The samples are intended for use by artists and designers as well as by scientists. With a relatively small number of samples, material is provided for constructing color scales and charts with colors uniformly spaced in six directions in any chosen part of color space. The OSA‐UCS set provides a “storehouse of color‐contrast information in efficient form.” It provides useful color research material such as has never before been available.
Formulation of a Nonlinear Model of Chromatic Adaptation
Authors: Nayatani Yoshinobu , Takahama Kotaro , Sobagaki Hiroaki 
Published: June 2007

AbstractA chromatic‐adaptation model which consists of a modified von Kries and a succeeding nonlinear transformation is formulated provided that a medium‐gray background is always used as an adapting field. The formulation uses (1) the absolute tristimulus values in luminance units, (2) the principles of brightness and achromaticness constancy for a medium‐gray sample on the same medium‐gray background, (3) a simple power law whose exponent increases with an increase of the effective adapting level of each of three visual mechanisms, and (4) the noise components. Predictions are compared between the new nonlinear model and the linkage model of Takahama et al. for the chromatic‐adaptation effect between CIE Illuminants D65 and A and also for the Hunt effect.
Assessment of Color‐Measuring Instruments
Authors: Billmeyer Fred W. , Alessi Paula J. 
Published: June 2007

AbstractThe U.S. Army has undertaken a program to develop an instrumental method for assessing the acceptability of textiles for color difference from a standard. This article reports the results of the first phase of the program, an assessment of three commercial color‐measuring instruments (Diano Match‐Scan, Hunter D‐54P‐5, Macbeth MS‐2000) for objective textile acceptability judgment. It is concluded that the three instruments are essentially equivalent in the precision and accuracy of the measurement of color and color difference using a wide variety of samples, at least over periods of up to seven weeks. All measures of repeatability lead to the conclusion that the uncertainties involved are well below the just‐perceptible color difference. Levels of absolute accuracy achieved depend greatly on the details of operation, data treatment, and calibration, but are considered satisfactory for each of the instruments tested. With respect to certain other parameters, the performance of the instruments is less satisfactory. Rejection of the specular component differs significantly among the three, as does the selection of weights for tristimuus calculations. One instrument, as tested, exhibited significant sensitivity to weave orientation in textile samples. Finally, we find that the distributions of tristimulus values obtained with each of the instruments show large deviations from normality, severely limiting the significance of conventional statistical treatment of such data.
Comparison of correcting methods for chromatic adaptation used for color‐rendering specification
Authors: Fuchida Takayoshi , Mori Leo 
Published: June 2007

AbstractRecently, several methods for correcting for chromatic adaptation have been proposed by Richter, Bartleson, Nayatani, and others. Psychometric‐chroma coordinates are calculated according to these methods for surface colors illuminated by various light sources, and are compared with the results of subjective experiments on color appearance. For this purpose some experiments using saturated color illuminants are included. The nonlinear transformation proposed by Nayatani and others applied in CIELAB space correlates best with the subjective appearance of surface colors.
Energy transfer between fluorescent organic pigments
Authors: Billmeyer Fred W. , Hepfinger Lisa B. 
Published: June 2007

AbstractEnergy transfer between fluorescent organic pigments (fluorophors) dispersed in a paint vehicle was studied for mixtures of a yellow, a red, and an orange fluorescent pigment, and for mixtures of these with titanium dioxide. Radiative energy transfer occurs among the fluorophors, but not between them and titanium dioxide A shift to longer wavelengths of the emission peak of a fluorophor with increasing paint‐film thickness was noted and was ascribed to reabsorption and reemission of fluoresced radiation within the overlapping excitation and emission region typical of these organic fluorophors.
Colors of dope and yamn of spun‐dyed cellulose acetate
Authors: Nava Alberto , Bianchi Donate , Pitea Demetrio 
Published: June 2007

AbstractA method of color control of bulk‐dyed cellulose acetate is described, based on the transmittance spectrum of the dope. Control can be effected only if the spectrum is recorded from thick samples which amplify the absorption from small amounts of impurities that later cause unacceptable color differences on the yarn. The calculation of the reflectance spectrum, and hence the color, of the yarn from the transmittance spectrum of the dope by Kubelka‐Munk theory is not satisfactory due to faint turbidity of the ‘bright’ dope. The reflectance spectrum of the yarn can be calculated from a series expansion of the experimental Lambert law absorption coefficient with very satisfactory results. A fully computer‐managed color‐control method is employed successfully in industrial practice.
A flaw in equations for predicting chromatic differences
Authors: Boynton Robert M. , Nagy Allen L. , Olson Conrad X. 
Published: June 2007

AbstractMany formulas for predicting perceived color differences require that three terms be squared prior to the extraction of the square root of their sums. Two of these terms relate to chromatic differences measured along tritan and red‐green axes. The root‐mean‐square calculational procedure predicts that the relative directions of simultaneous chromaticity changes along these principal axes should not affect the perceived color difference. Experimental data are presented which strongly disconfirm this prediction.
Formulation of blends of precolored nylon fiber
Authors: Burlone Dominick A. 
Published: June 2007

AbstractTwo‐constant Kubelka‐Munk formalism was used to describe the color of blends of precolored nylon fibers. Pseudo‐Kubelka‐Munk absorption constants K and pseudo‐Kubelka‐Munk scattering constants S were calculated using masstone samples and blends of colored fiber with white. A masstone means 100% colored fiber in which no white or black is mixed. Various mixtures with white were tried and no systematic dependence of the calculated optical parameters on composition was discernable. With some colors, notably yellow and orange, mixtures with black were required for the calibration. Accurate color matches were obtained using the two‐constant formalism especially when the proposed match contained the same primary fibers as did the standard. For matches in which the primary fibers used in the sample differed from those in the standard, the closeness of the visual match depended on how closely the primary colors in the sample resembled those in the standard. Since the eye can discern individual colors in a fiber blend, it was possible to have a visual mismatch despite colorimetric equivalence. With a large enough group of primary colors, it was generally possible to find one or more alternative formulations which matched the standard. Sample‐preparation and measurement errors were found to be critical for determining color‐matching accuracy. All of the color‐matching error could be accounted for in terms of the sample‐preparation and measurement errors alone. This suggests that the sampling error was, in fact, a limiting factor in determining color‐matching accuracy.
The distimulus method of assessing luminous efficiency of the spectrally pure stimuli
Authors: Fry Glenn A. 
Published: June 2007

AbstractIn the tristimulus method of photometry, the luminance of any monochromatic stimulus can be assessed by matching it in hue and brightness to a mixture of two primaries and then reducing the saturation of the test stimulus to obtain a complete match. The luminances of the stimuli are considered to be additive, and the luminances of the two mixtures to be equal. In this article it is shown that if the primaries are properly chosen, it is not necessary to desaturate the test stimulus. The difference in saturation between the test stimulus and the mixture of the two primaries can be ignored and it may be assumed that the luminance of the test stimulus is equal to the sum of the luminances of the two primaries when the mixture and the test stimulus match in hue and brightness. Luminous efficiencies assessed in this way agree well with assessments based on flicker photometry. Flicker photometry has been used to assess the luminances of the primaries.
Carbon black as a dulling agent for nylon 6 filaments and the lightfastness of dyes on dulled filaments
Authors: Datye Keshav V. , Mishra Sachi , Srivastava Jitendra 
Published: June 2007

AbstractNylon 6 filaments containing 0–1.5% carbon‐black pigment are dyed to different depths of shade. The colour on the substrate is evaluated on CIELAB a* b* diagrams at given concentrations of carbon black and dye. The carbon‐black pigment acts essentially as a neutral dulling agent and only with a few dyes does it appear to alter the hue angle slightly. Thus, it is possible to use nylon 6 filaments containing carbon‐black pigment to produce dull shades by the overdyeing process. The dyed samples thus produced are exposed to mercury‐lamp light as well as daylight. The lightfastness is evaluated visually using the Blue Wool Scale. There is a remarkable improvement in the lightfastness of all dyes on nylon 6 containing carbon‐black pigment. The carbon black in the filament appears to protect both the dye and the polymer from the degrading action of actinic radiation. However, the remarkable improvement in the lightfastness is essentially due to the optical effect.
Theoretical and practical aspects of selected fiber‐blend color‐formulation functions
Authors: Burlone Dominick A. 
Published: June 2007

AbstractColor matching blends of precolored fiber using three different methods was studied. Best color‐matching accuracy was obtained using a two‐constant Kubelka‐Munk (KM) procedure. First‐formula color differences averaged 1.6 CIELAB units and were found to be within the experimental error of 1.6 CIELAB units. Useful approximations were obtained using the methods proposed by Friele and by Stearns. First‐formula color matches averaged 2.4 CIELAB units for the Stearns and 2.7 CIELAB units for the Friele methods. The methods are mathematically compared and the merits of each are discussed. Where possible, interpretation of the empirical parameters each method employs is attempted. It is pointed out that absorption and scattering constants calculated for fibers using the KM formalism are not true KM absorption and scattering constants. It is demonstrated that too literal an interpretation of these constants leads to apparent anomalies. It is shown that the fiber KM scattering constants which are normally considered unchanged as dye is applied cannot be considered unchanged if these same fibers are subsequently to be used in blends with other colored fibers.
Perceptual factors affecting colour order systems
Authors: Hunt Robert W. G. 
Published: June 2007

AbstractThe perceptual colour attributes relevant for ordering unrelated, related, luminous, and nonluminous colours are different insome respects. Colour order systems for related nonluminous colours have been the most fully developed, but different systems depend on different types of experimental data, such as equalization of small perceptual differences, colour scaling, and some relationships to properties of the stimuli. The resulting systems have both similarities and differences, which are worthy of careful study. Chromatic adaptation is an important factor affecting and appearances of samples of colour order systems viewed in illuminants of various colours, and requires further study.
Reader survey results
Authors: Alman David H. 
Published: June 2007

AbstractA survey of the subscribers to Color Research and Application was conducted by the publisher in January, 1983. The results of the survey are reported here with special emphasis on those sections of the survey which indicate the readers' views on editorial content. Based on our analysis of the survey results, the editorial board is announcing several changes in policy and content. The intent of these changes is to tune the information presented in Color to better meet the readers' needs as indicated by the survey.
Color samples for colorimetric fidelity testing in television
Authors: Hisdal B. 
Published: June 2007

AbstractThe case for testing television (TV) colorimetric reproduction performance for groups of colors is discussed. The groups consist of colors which have some characteristic in common, like strong or moderate saturation. Such groups actually contain a large number of discernible colors but these are for testing purposes represented by a set with a limited number of reference samples. In recommended methods the evaluation of the performance for the group is based on the average of the individual color differences for the samples in the set. This average is here based on the CIE 1976 color difference ΔEuv* and designated ΔEa*. The question investigated is what properties the reference samples in the set should have to make D̊Ea* the best estimator of performance for the whole group. It is shown that the samples should be chosen for evenness in distribution and uniformity in lightness, preferably representative of average scene lightness. These points seem to have been overlooked for some presently recommended sets as illustrated by an example. Experimental data for TV cameras indicate that a collection of 10 color samples might be satisfactory for colorimetric acceptance testing.
Image reproduction colorimetry
Authors: Pearson Milton 
Published: June 2007

AbstractThe field of colorimetry appears to be arbitrarily divided into two areas, matching‐and‐formulation colorimetry and image‐reproduction colorimetry. It is believed that the end uses for the colorimetric data and the methods of color generation are sufficiently different in these two areas to warrant this division. Conditions that contribute to this division are the need for metamerism and the use of limited sets of primaries in reproduction work, the compromise of lightnesses due to tone reproduction, the availability and proper use of instrumentation compared to that desired, and the viewing conditions of the standard observer. All these contribute to produce significantly larger color differences in image‐reproduction work than in matching and formulation. However, workers in reproduction studies can still draw useful conclusions when these conditions are properly understood.
A FORTRAN program for predicting the effects of chromatic adaptation on color appearance based on current CIE recommendations
Authors: Berns Roy S. 
Published: June 2007

AbstractThe CIE has recently recommended for field trial a method for predicting corresponding colors with a change in chromatic adaptation. To aid the CIE in collecting results illustrating the accuracy of these predictions, a FORTRAN program currently used by the Munsell Color Science Laboratory is listed along with test data. This chromatic‐adaptation transform can be used to calculate CIELAB or CIELUV metrics for non‐daylight illuminants, indices of illuminant metamerism, and indices of color constancy. Including this transform in these calculations, it is hoped, will result in metrics with better correlation to visual assessments. It is hoped that readers will implement this method, compare the effectivness of this chromatic‐adaptation transform to visual evaluations, and report their results to CIE Technical Committee 1–06.
Colour and appearance in nature
Authors: Hutchings John B. 
Published: June 2007

AbstractGeneral IntroductionAfter spending many years working on colour and appearance in industry, I became aware of a gross ignorance of the origin of the colour and beauty existing around me in nature. The results of the succeeding awakening formed the theme of my retiring address as Chairman of The Colour Group (Great Britain) on 13th May, 1981, at the Royal Institution, London. Life, it seems, was destined to become coloured from the start and it has become a more and more colourful place as evolution has continued. Colour and design are vital, in different ways, to the life and perpetuation of different biological systems. I have attempted to amalgamate the views of the biologist, biochemist, anthropologist, and physicist (among others), to give a personal overall view of the driving forces and principles of appearance and colouration in the world of nature. The three articles to follow consider, first, the mechanisms which result in the colour of primary producers using the photosynthetic process; second, the mechanisms which produce colouration and total appearance in flowering plants and animals; and third, human colouration and man's use of colour, stopping short of modern technology. I hope that these findings will add to the everyday joy which you can experience in your natural environment.
Computer simulation of the error sensitivity of colorant mixtures
Authors: Alman David H. 
Published: June 2007

AbstractComputer simulation of colorant mixtures is employed in this study to investigate color sensitivity to composition errors in four‐component blends. Color sensitivity as related to mixture composition is reported for concentration‐dependent strength errors and for concentration‐independent weighing errors. Color sensitivity to both types of errors varies regularly with the mixture‐composition variables. A conclusion of the study is that predictable changes in the color sensitivity to composition errors are observed in different regions of colorant‐mixture‐composition space.
Evidence for the three spectral responses of the normal human visual system
Authors: Thornton W. A. 
Published: June 2007

AbstractSkilled human color‐matching experts developed 317 sample pairs that matched to them in daylight (the Bayer sample sets MV68 and AA17 of about 1970). One hundred of these pairs intersect only at three well‐defined wavelengths, near 458 nm, 541 nm, and 611 nm, and thus indicate visualsystem response peaks.
The effect of background luminance on color recognition
Authors: Jacobsen Alan R. 
Published: June 2007

AbstractThe effect of background raster luminance on the ability to learn and recall color‐coded information was studied via a paired‐associates paradigm. Twenty variously colored circles, paired with two‐digit numbers, were presented on a color‐graphics CRT terminal. On test trials each colored circle was presented by itself and observers were required to recall verbally the two‐digit number that was previously paired with the target color. Time to recall as well as actual responses were both recorded. Two raster luminance levels were tested: dark or perceptual black and one that appeared to be a shade of middle gray. Ten out of 10 observers reached the learning criterion with the middle‐gray background, while only 10 out of 15 were able to reach the criterion with the black background. In addition, those observers who reached the criterion on the black background still made significantly more errors than the observers presented with the middle‐gray background. There were no significant differences, however, in time to recall between the two types of backgrounds for observers who reached the learning criterion. These results are discussed in light of the CIELUV color‐difference metric AE*uv.