bluuebunny/crossref_metadata_2025_split huggingface dataset:
Absolute reflectance factor calibration for goniospectrophotometry
Authors: Fairchild Mark D. , Daoust Denis J. O. , Peterson Jason , Berns Roy S. 
Published: June 2007

AbstractCurrently, spectrophotometric standard reference materials are calibrated only using the CIE recommended illumination and viewing geometries. A need exists for standards that have been calibrated at many other combinations of illumination and viewing angles. The common practice has been to assume that a primary transfer standard such as BaSO4 is Lambertian even though its non‐Lambertian behavior is well documented. This study was undertaken to develop a practical standard for this type of metrology. Two diffuse materials, BaSO4 and PTFE, were characterized goniospectrophotometrically. Bidirectional absolute spectral reflectance factors were determined for 60 combinations of illumination and view angles in a single plane. Neither material was found to be Lambertian and both failed to completely depolarize reflected radiation. The results were modeled using principal components analysis. The resulting model allows the determination of bidirectional spectral reflectances factors with a minimum effort. PTFE powder can be prepared repeatably with no significant effect on the measured reflectance properties, thus indicating that it would be a suitable primary transfer standard for goniospectrophotometry.
Model of saturation and brightness: Relations with luminance
Authors: Pridmore Ralph W. 
Published: June 2007

AbstractThe model is simple: For flicker luminance stimuli and maximum purity, the hue cycle's relative luminance (computed from CIE data) is reciprocal to relative saturation. Brightness/luminance ratio B/L is proportional to relative saturation S, i.e., B/L = 1.5 S1/4. S times B/L ratio gives relative saturation for brightness stimuli; just as relative luminance times B/L ratio gives brightness. Predictions for any purity agree with data on saturation discrimination, color appearance in CIE space, B/L, and CIE brightness Vb. Predictions support Hunt's concept of “colorfulness” and indicate its causal role in proporitionality of S and B/L.
Application of neural networks to computer recipe prediction
Authors: Bishop J. M. , Bushnell M. J. , Westland S. 
Published: June 2007

AbstractConventional mechanisms for computer colorant formulation commonly employ the Kubelka‐Munk theory to relate reflectance values to colorant concentrations. However, there are situations where this approach is not applicable and hence an alternative is desirable. One such method is to utilize artificial intelligence techniques to mimic the behavior of the professional colorist. The purpose of this paper is to describe recent research being carried out at Reading University, sponsored by Courtaulds Research, that utilizes collections of cellular automata, known as neural networks, in the problem of recipe prediction.
Applications of set theoretic methods to color systems
Authors: Trussell H. J. 
Published: June 2007

AbstractA vector‐space approach to color systems has been shown to be useful in describing metameric effects and producing metamers under different illuminations. The vector‐space approach has also been used to describe color scanning and reproduction systems. This article extends the applications presented in previous work by introducing set theoretic concepts which allow the addition of realistic constraints. The set theoretic methods allow the full range of solutions of color problems to be explored by allowing a set of solutions to a particular problem formulation. The applications discussed here include producing realizable metamers and the design of scanning filters.
Optimization algorithm for designing colored glass filters to simulate CIE illuminant D65
Authors: Liu Yan , Berns Roy S. , Shu Yuexin 
Published: June 2007

AbstractAn optimization algorithm is described and was used to design colored glass filters arranged either side‐by‐side, or side‐by‐side in series for simulating CIE illuminant D65. Many optimal results were obtained in acceptable CPU time; the category of the D65 daylight simulators that were constructed was BE (CIELUV). These D65 daylight simulators have the advantages of metamerism index B in the visible range, a high color‐rendering index, and high light efficiency. Additionally, they use tungsten‐halogen lamps of low correlated color temperature.
Cesia: A system of visual signs complementing color
Authors: Caivano José Luis 
Published: June 2007

AbstractColor theory has been worked up by some researchers in order to consider factors such as transparence, brightness, opacity, etc., but no color order system has been devised to include these variables in addition to the usual three. This work proposes to treat these factors as theoretically separate from color (even if they are related with it), developing an order system for them. When it is taken parallel to color, this system helps to describe all the visual perceptions produced by light stimuli.
Effects of luminance level on the saturation function: Sensitivities based on saturation discrimination
Authors: Kimura Eiji 
Published: June 2007

AbstractThe saturation of a monochromatic light λ is defined as the reciprocal of the just noticeable colorimetric purity ΔP(λ) from a white, which is a conventional definition having been used previously often. The present study measures saturation functions of monochromatic lights at various luminance levels ranging from 10 to 1000 Td. The main result of this article is that the saturation function systematically changes in shape with the luminance level; as the luminance increases, the values of 1/ΔP(λ) relatively increase for shorter wavelengths. The chromatic sensitivity function C(λ) is defined by the reciprocal of the radiance of a monochromatic light λ added to the white field in order to detect a difference in chromaticity from the equal‐luminance reference white. The C(λ) functions at various luminance levels are shown to have three peaks at the short‐, middle‐, and long‐wavelength regions. These peaks are similar to those of the increment threshold functions, and the saturation function can be approximated by the ratio of the increment threshold spectral sensitivity to the relative luminous efficiency, except for the 570 nm data.
Psychophysical verification of the accuracy of color and color‐difference simulations of surface samples on a CRT display
Authors: Rich Danny C. , Alston David L. , Allen Larry H. 
Published: June 2007

AbstractWe describe an experiment to visually quantify the accuracy of the simulation of the color and color‐difference of surface samples on a CRT display unit. A gray‐scale‐anchored, magnitude‐estimation experiment was performed to assess the absolute quality of the simulations and a forced‐choice, paired‐comparisons experiment was performed to assess the relative quality of the simulations. Results indicate that an average color difference for overall simulation accuracy can be under 3.0 CIELAB color‐difference units for highcolor‐temperature sources, and slightly worse for low‐colortemperature sources. All simulations were well under the 6 to 12 unit differences reported for typical color reproduction. Possible reasons for the residual color differences between the current simulations and the theoretical limit are presented.
Use of calibrants in food colour measurement: An international cooperative study
Authors: Kent M. , Calvert A. , Macdougall D. , Malkin F. , Witt K. 
Published: June 2007

AbstractThe agreement between a number of laboratories and instrument types (tristimulus colorimeters, spectrophotometers) in the measurement of colours distributed around a central point in colour space was studied. The improvement gained by calibration against the central colour as opposed to calibration against a white standard is quantified and its variation with distance from the centroid is shown. In this way the limits of applicability of the so‐called hitching post procedure are defined.
Spatial sensitization and adaptation in a long‐wavelength cone pathway
Authors: Finkelstein Marcia A. 
Published: June 2007

AbstractFlashed‐field sensitivities measured with a long‐wavelength probe have a red/green shape when stimuli are presented on a steady background but resemble the L‐cone absorption spectrum in the dark [M. A. Finkelstein, M. Harrison, and D. C. Hood, Sites of sensitivity control within a long‐wavelength cone pathway, Vision Res. 30, 1145–1158 (1990)]. We previously speculated that this could be due to concealed color opponency; receptive‐field surrounds, fed by M cones, are eliminated under dark adaptation. The current study tested this hypothesis with a sensitization paradigm. Thresholds were measured for a 640‐nm probe presented on flashes of two sizes. Data were obtained in the dark and on a 4.0‐log10 td steady background. The results suggest a model in which the L cones comprise a center mechanism and both M and L cones a weaker inhibitory surround. Dark adaptation eliminates only the M component of the surround.
Color notation conversion by neural networks
Authors: Tominaga Shoji 
Published: June 2007

AbstractThis article describes a new method for color‐notation conversion between the Munsell and CIE color systems by means of neural networks. A multilayer feedforward network is regarded as a nonlinear transformer which is trained to learn a mapping between the two color spaces. We adopt the backpropagation learning rule for the training. The mapping is then realized in a simple network architecture in which nonlinear units are linked in parallel and in layers. The tables of data by Newhall, Nickerson, and Judd are used in computer simulations of training and testing phases. We determine an effective network structure and training strategy based on experiments under different conditions. The conversion accuracy is demonstrated in both directions, Munsell‐to‐CIE and CIE‐to‐Munsell. In the neural network method, it is not necessary to use a special database. The knowledge of the mapping is stored in a small set of weighting parameters in the network. We point out that the proposed method for color‐notation conversion provides several potential advantages over the conventional approach based on interpolation of the data tables.
CRT colorimetry. Part II: Metrology
Authors: Berns Roy S. , Gorzynski Mark E. , Motta Ricardo J. 
Published: June 2007

AbstractThe colorimetric characterization of computer‐controlled CRT displays require radiometric measurements with high precision and accuracy in order to achieve acceptable colorimetric accuracy in defining stimuli generated with this type of imaging modality. Precision and accuracy requirements for photometers, colorimeters, and spectroradiometers were evaluated. When models are used to relate digital counts defining a stimulus and resulting spectral radiant exitance, displays are assumed to exhibit channel and spatial independence. A variety of tests and the results of evaluating four imaging systems are described. From these analyses, measurement accuracy is mainly limited by wavelength scale in the case of spectro‐radiometers and filter fit in the case of colorimeters. Measurement precision is limited by the number of significant figures for fixed‐range devices and signal‐to‐noise limitations for low‐luminance stimuli. Display accuracy is limited by a lack of channel and spatial independence. Display precision is mainly limited by the electronic design of the display and the stability and load independence of the gun amplifiers. © 1993 John Wiley & Sons, Inc.
Rod contribution to large‐field color matching
Authors: Shapiro Arthur G. , Pokorny Joel , Smith Vivianne C. 
Published: June 2007

AbstractThe linear algebraic features of foveal colorimetry do not apply to 10° degree colorimetric fields. A light presented as a foveal 2° field stimulates the three classes of cone photoreceptors, and a light presented as a 10° field stimulates the cone and rod photoreceptors. While no more than three primary lights are required to match either of these lights, large‐field color matches with three primaries do not obey Grassmann's laws of linearity because the relative contribution of the rod signal to a color match changes with retinal illuminance. A three‐primary set of color‐matching functions (CMFs) affected by rodintrusion, therefore, cannot serve as the basis for colorimetry. Stiles and Burch removed the effects of rod activity from their 10° color‐matching data to create a set of CMFs that have the same linear algebraic features as foveal, 2° colorimetry. They did this by selecting the primaries appropriately, making the matches at high retinal illuminance levels, and removing the small residual effects with numerical techniques. the resulting CMFs formed the major portion of the CIE 1964 10° Standard Observer. These CMFs describe color matches at the level of the cone‐photoreceptor and, therefore, can be generalized to predict color matches with any set of primaries, but they cannot account for the effects of rod activity in the matching sample. If two colorimetric fields differ in the amount of rod activity they produce, calculations with the 1964 Standard Observer may predict their metamerism inaccurately. This article summarizes Stiles and Burch's methods for removing the effect of rods, gives examples of the implications for colorimetry, and suggests procedures for preventing the adverse effects of rod activity in applied situations. It also shows that three recently published sets of 10° CMFs may be influenced by the effects of rod activity. © 1994 John Wiley & Sons. Inc.
A comparative study of color measurement lntstrumentation
Authors: Rodgers James , Wolf Kaye , Willis Norm , Hamilton Don , Ledbetter Ralph , Stewart Curtis 
Published: June 2007

AbstractA multiplant Quality Improvement Team [QIT] was firmed to develop and implement an evaluation program for various color measurement .systems as potential replacements for the then‐current aging systems. The emphasis qf this article is the analytical methodology utilized to evaluate the various color systems. The evaluation program consisted cf two phases. Phase I was a general overview/review of several systems, while Phase II was an extensive internal comparative evaluation measurement systems. These were Milton‐Roy's ColorMate HDS, HunterLab's Ultrascan, Datacolor's CS‐5, and BYK‐Gardner's The Color Sphere [TCS]. The main comparison criteria were interinstrument agreement [agreement between two instruments ofthe same system], user‐friendly software and computer interface capability, vendor amenability to a long‐term logistical and maintenance relationship, and price. All systems were evaluated by duplicate measurements on various color tiles, yarns, and polymer flakes‐over 1600 measurements on each system. The systems were compared with an instrument matrix, a decision matrix, and a product matrix. The instrument matrix was a comparison qfinstrument parameters, software/math treatments, and economics. The decision matrix was a forced ranking of each system by each criteria category [1–4 scale, with 1 representing the best and 4 representing the worst]. The product matrix accentuated the relative importance ofone criterion category over another by multiplying the forced ranking by the criticality of the category. The criticality of a given category wus determined by consensus within the QIT. Thr combination qf the three matrices allowed the evaluator[.s] t o select the color rneasuremmt system that best satixfied the color measurement needs and requirements of their facility and their products. For this evaluation, all ofthe evaluated systems were superior to the then‐current agingsystems. As a result of this methodology, one instrument emerged as clearly superior. © 1994 John Wrley & Sons, Inc.
Color Matching in Paints Using a Method of Linear Programming
Authors: Bai Fengxiang , Zeng Hua , Yi Jidong , Liao Ningfang , Guo Lurong 
Published: June 2007

AbstractThis note is based on 2‐constant Kubelka‐Munk theory and the first‐order approximat ion ofspectrum, presenting a method of linear programming to compute the recipes and to get the basic database quickly. A lot of experimental results in paints have shown that matching precision may be achieved by following this practice. © 1994 John Wiley & Sons. Inc.
Match prediction of highly fluorescent colors
Authors: Simon Frederick T. , Funk Robert A. , Laidlaw Ann Campbell 
Published: June 2007

AbstractColor formulation of fluorescent materials is not feasible with the usual methods used for nonfluorescent colors. Realizing the need for certain textiles that are dyed with fluorescent colorants, a technique was developed based on using certain dual‐monochromator measurements of the spectra of fluorescent colorants. to accomplish this formulation, a new spectral quantity independent of illuminant was developed for all fluorescent colorants. This is termed RELEX, which describes the relative excitation of the colorant. When this quantity is weighted by the spectral power distribution for a specific illuminant and factored for absorption by all ingredients in a mixture of colorants, the proper fluorescent emission is obtained, which can be added to the spectral reflected radiance factor, βs, for that mixture. Consequently, match prediction can be done for spectral radiance factor, βT, curves of fluorescent materials using an iterative estimation algorithm.
The calibration of instruments for the measurement of paper whiteness
Authors: Bristow J. Anthony 
Published: June 2007

AbstractThe pulp and paper industry traditionally measures a property called ISO‐brightness based on a filter function with an effective wavelength of 457 nm, but this is not a satisfactory measure of the appearance of the material. Currently there is a growing interest in determining a whiteness value based on the CIE‐whiteness equation with respect both to an indoor illumination and to the standardized D65 illuminant. This is not, however, merely a question of using the relevant mathematical functions. Many papers contain fluorescent whitening agents and this means that reproducible values can be obtained only if the instruments used are adjusted so that the relative UV‐content in the illumination falling on the sample is controlled to correspond to the chosen illuminant. the paper industry employs instruments with a well‐defined d/0° geometry, and the relevant ISO‐Standards also define a hierarchical calibration system, which enables all instruments to be calibrated with traceability to the perfect reflecting diffuser through a reference instrument. This calibration service has now been extended to include fluorescent standards assigned whiteness [D65/10°] values. This article describes the development of this calibration routine based on the absolute two‐monochromator instrument at BAM, Berlin.
Objective evaluation of color design. III
Authors: Kawamoto Naoki 
Published: June 2007

AbstractA psychological test was performed by using computergenerated color patterns, which were composed of ordered repeats of random color arrangements, and the effects of the repeat number were investigated. the results were analyzed in terms of power spectra of the Fourier transform of the color patterns, and it was clearly found that the psychological evaluation depended strongly not only on the amount but also on the degree of concentration (or scatter) of the power spectrum. Furthermore, in order to predict the psychological values of the color patterns, multiple regression analyses were done by using three models with 13, 14, and 15 specified variables that were obtained from the Fourier transform. It was found that the multiple correlation coefficient increased considerably by introducing the second‐order term of a variable that indicates the degree of concentration of the dynamic components, especially for the evaluation of beautifulugly or interesting‐boring. © 1995 John Wiley & Sons, Inc.
Assessment of the influence of paper formation on the fluorescence contribution to brightness
Authors: Kulikova Yana Y. , Schaepe Michael K. , Robbins Wayne B. 
Published: June 2007

AbstractPaper was produced under controlled conditions with a range of resultant formation and a constant level of fluorescent dye. Brightness and CIE‐Whiteness and the fluorescent contribution to brightness or whiteness were measured by directional and diffuse illuminations. Brightness, whiteness, and fluorescence variability were evaluated as the illuminated sample aperture diameter was varied from a maximum of 12.7 mm to a minimum of 6.0 mm over a broad range of paper formation. an increase in the variance of CIE‐Whiteness both including and excluding fluorescence is observed as formation degrades. the variance of the fluorescent contribution also increased, but not in a manner to suggest it is independent of the whiteness including or excluding fluorescence measurements. A higher level of instrument noise prevented a similar definitive concl usion for the fluorescent contribution to directional brightness, even though similar trends were observed. an increase in variance was observed for all whiteness and brightness measurements as viewing aperture size diminished. This suggests an opportunity to understand subjective appearance as a function of viewing aperture size. © 1995 John Wiley & Sons, Inc.
Testing colour‐appearance models: Guidelines for coordinated research
Authors: Fairchild Mark D. 
Published: June 2007

AbstractThese guidelines provide an overview of the many issues involved in generating visual data that can be used to evaluate the performance of colour‐appearance models. the three main sections of these guidelines outline the parameters that must be evaluated and controlled in experimental setups for colour‐appearance experiments, suggested psychophysical techniques for gathering the data, and some suggested techniques for data analysis. Experimental parameters addressed include models to be tested, illumination conditions, background and surround conditions, types of stimuli to be used, and issues relating to viewing technique. the psychophysical techniques of magnitude estimation, matching, and direct model testing (paired comparison) are described. Data analysis techniques for the evaluation of colour‐appearance scales, corresponding‐colours data, and model performance scales are suggested.
Considering the surround in device‐independent color imaging
Authors: Fairchild Mark D. 
Published: June 2007

AbstractWhen viewing images, the relative luminance of the surround has a profound impact on the apparent contrast of the image. For this reason, photographic transparencies intended for projection in a darkened room are produced with an objective contrast substantially higher than that necessary for optimum reproduction as prints viewed in an illuminated surround. the dark surround causes the image elements to appear lighter and this effect is stronger for darker colors resulting in a loss in perceived contrast. This effect is also of great importance in deviceindependent color imaging since resultant images might be observed in a wide variety of media and viewing conditions. Research on psychophysical scaling of brightness and lightness and the effects of background and surround relative luminance on lightness and chroma is reviewed. the importance of this research for device‐independent color imaging systems is described along with the prediction of these effects using the RLAB color‐appearance model. Finally, experiments testing the use of RLAB and other color‐appearance models in cross‐media color reproduction applications are described.