bluuebunny/crossref_metadata_2025 huggingface dataset:
Color tolerance feasibility study comparing crt‐generated stimuli with an acrylic‐lacquer coating
Authors: Berns Roy S.
Published: June 2007

Visual color tolerances were calculated from observations made on difference pairs around a single green color center. The comparison was made between observations done for actual acrylic‐lacquer samples and a simulation of the sample pairs on a computer‐controlled CRT display. A light booth with simulated daylight was used to illuminate the surface colors and to provide surround illumination for the CRT. The luminances of the CRT and light booth were equalized at 150 cd/m2. Fifteen observers judged color differences relative to a near‐gray anchor pair under three different conditions: CRT stimuli viewed with a dark surround, CRT stimuli viewed with a light surround generated by the light booth, and the surface colors. Probit analyses were used to transform population responses to estimates of equivalent color tolerances to the anchor pair, fiducial (confidence) limits about the tolerances, and population standard deviations. Observations were less precise (higher standard deviations) for CRT stimuli. This statistically significant difference was presumed due to differences in spatial and cognitive attributes. Despite these differences, observers' color tolerance determinations were not statistically different from one another or from previous experiments of the same color center but judged under a luminance three times higher than the current experiment. Results indicated that the experimental design was a reasonable approach to using CRT‐generated stimuli for measuring visual color tolerances in a manner that correlates to surface‐color judgments.
Formulation and testing of an incomplete‐chromatic‐adaptation model
Authors: Fairchild Mark D.
Published: June 2007

A mathematical model of chromatic adaptation for calculating corresponding colors across changes of illumination based on the Hunt color appearance model is formulated and tested. This model consists of a modified von Kries transform that accounts for incomplete levels of adaptation. The model predicts that adaptation will be less complete as the saturation of the adapting stimulus increases and more complete as the luminance of the adapting stimulus increases. An experiment is described in which achromatic appearance is measured for various adapting conditions. The model is tested with these experimental results as well as results from another study and found to be significantly better at predicting corresponding colors than other proposed models.
Propagation of random errors in spectrophotometric colorimetry
Authors: Fairchild Mark D. , Reniff Lisa
Published: June 2007

Every physical quantity with an a priori range of numerical values constituting a continuum is subject to error in its measurement. It is important to report the highest amount by which any measured quantity might be in error. Optical radiation measurements are typiclly based on determination of the ratio of the instrumental reading of a calibrated standard to the instrumental reading of the test sample. There are random and systematic errors in both the instrumental readings and the calibration values. The uncertainty in a calculated value due to random error in its constituents can be determined using well known techniques of error propagation. Examples of error propagation through spectral reflectance factor measurements and colorimetric calculations are presented. The standard deviations of CIELAB coordinates for typical measurements can be as high as 0.258 due only to random errors in the calibration chain.
Efficient uniform illuminators using diffusing optics
Authors: Venable William H.
Published: June 2007

Unless specimens are illuminated uniformly with respect to both position on the specimens and directon of incidence, reliable visual judments of and measurements of object color difference cannot be made. Devices producing illumination suitable for color difference evaluation can be made using an integrating sphere as and optical component intermediate between the primary source of light and the illuminated area. Properly designed, such sources can be as efficient as the more common sources using imaging optics. Techniques for designing such sources are described.
Efficiency and uniformity comparisons between a diffusing‐optics source and a lamp‐imaging source
Authors: Spadaro John
Published: June 2007

Integrating spheres, when used in a light source, offer a highly uniform illuminated area and, when used in conjunction with a reflective diffuse sleeve, can offer effeciencies equivalent to that of a lamp‐imaging reflector system. The diffuse sleeve provides a means for the sphere to use light normally lost while maintaining a beam that is substantially more uniform than the reflector system. This article describes a test comparison between a modified diffuse integrating sphere source and a lamp‐imaging optics source.
Determination of correlated color temperature based on a color‐appearance model
Authors: Walter Wolfgang
Published: June 2007

The present method of determining the correlated color temperature of an illuminant is based on the obsolete CIE 1960 u,v chromaticity diagram. A new method is proposed that is based on Hunt's color‐appearance model for unrelated colors. Analytic functions were derived for the blackbody locus in appearance space to simplify the computation. CCT was calculated for some light sources and the results were compared to those obtained by the present method.
Color rendering of supplementary artificial lighting
Authors: Embrechts J. J.
Published: June 2007

Many interiors may be lit by daylight and artificial light; the CIE color rendering index (CRI) of the sources alone is not a characteristic of the complex situation. It is the purpose of this article to derive the general principles leading to the determination of the CRI distribution in such an interior. the CRI is expressed as a function of the proportion α of the combination, for several types of daylight and artificial light. It is shown that the dependence of the CRI on α is linear for supplementary artificial lightings which have the same chromaticity as daylight. Otherwise, nonlinearities are introduced. the time variation of the CRI is also analyzed.
Color classification of natural color images
Authors: Tominaga Shoji
Published: June 2007

The present article describes a color classification method that partitions a color image into a set of uniform color regions. The input image data are first mapped from device coordinates into the CIE L*a*b* color space, an approximately uniform perceptual color space. Colors used to represent a natural color image are classified by means of cluster detection in the uniform color space. The basic process of color classification is based on histogram analysis to detect color clusters sequentially. The principal components of a color distribution are extracted for effective discrimination of clusters. We present an algorithm for sequential detection of color clusters in the uniform color space, and the related algorithms for region processing and color computation. The performance of the method is discussed in an experiment using three kinds of natural color images.
Toward a more accurate and extensible colorimetry. Part Iii. Discussion (continued)
Authors: Thornton William A.
Published: June 2007

The instrument used to gather the data of this article, a bright split‐field visual colorimeter coupled by quartz light pipe to a spectroradiometer, generated many pairs of lights visually‐matching to one of six normal human observers. an accurate absolute spectral power distribution (SPD) was obtained for every such viewed light. Three disparate primary‐sets were used. Large errors in chromaticity and brightness (represented by luminance), computed by the 1964 CIE Standard Observer, were found to pervade the results. Problems are introduced by the use of maximum‐saturation CMFs, by transformation of primaries, by the structure of the CIE chromaticity diagram, and by measurement inaccuracies of the far past. In Part III, alternative derivations of weighting functions, multiplied against the absolute SPDs of the visually‐matching lights to obtain what are called tristimulus values, are shown to reduce errors in computed chromaticity. an alternative brightness function, of complexity commensurate with that of the three‐input normal human visual system, is shown to correlate considerably better to perceived brightness of white and colored lights than does computed luminance. an alternative chromaticity diagram is constructed of two chromatic terms of the brightness function, as a constant‐perceived‐brightness plane (which conventional diagrams are not), and avoids problems inherent in the conventional diagram.
The Colorcurve Systems®
Authors: Stanziola Rulpha
Published: June 2007

The Colorcurve System is first and foremost a system for color communication. It provides a direct means of communication between spec (fiers or creators of color and the manufacturer of colored products. It is a combination of a visual and numerical system. The system is made up of four main elements: (1) Aim points in CIE L*a*h* color space; (2) Physical representation of the aim points; (3) Data tables and numerical descriptions of the aim points; and (4) Computational methods andlor computer software. A simple notation system that can be easily understood by both creative people and industrial technologists was developed. The numerical description of each aim point can aid manufacturers in getting acceptable color matches in a variety of materials because it fits in with the procedures used for computer color matching. © 1992 John Wiley & Sons, Inc.
Colour appearance of stained glass windows
Authors: Schanda J. D.
Published: June 2007

The ruby reds and the strong blues of the stained glass windows of Romanesque and Gothic cathedrals are some of the most magnificent pieces of craftsmanship mankind has produced. According to our knowledge, no colorimetric attempt has been made to understand the visual impression produced by them. Modern colour‐appearance models permit the description of the colour impression produced by chromatic stimuli under changing adaptation conditions. In the present article, an attempt is made to model the visual situation and to use the colour‐appearance model developed by Nayatani and co‐workers for colorimetrically describing the observed effects. In model experiments, “extra brightness” was found when changing the direction of view from the dark surrounding to the well lit stained glass window. Calculations based on the Nayatani model yielded similar extra brightness and extra colourfulness, in good agreement with visual observations.
Confusion lines of dichromats
Authors: Fry Glenn A.
Published: June 2007

A way has been found to plot the mixture data of a protanope or a deuteranope on a constant luminance mixture diagram to show that the confusion lines are parallel to the line tangent to the red end of the spectrum locus. In the case of a tritanope the confusion lines are parallel to each other on a constant luminance diagram. These constant luminance diagrams are projective transformations of the CIExy diagram. My confusion lines converge close to the copunctal points located by Walraven on the CIE diagram. © 1992 John Wiley & Sons, Inc.
Suggested modification of CMC formula for acceptability
Authors: Brill Michael H.
Published: June 2007

The Colour Measurement Committee [CMC] formulas for color‐difference acceptability do not describe ellipsoids in CIELAB space, but the literature describes the acceptability surfaces as ellipsoids. It turns out that the discrepancy does not affect computational results [as long as the CMC parameter c is 1]. However, if the ellipsoid equations were substituted for the existing quartic formulas, the possibility for conceptual confusion would be much reduced. © 1992 John Wiley & Sons, Inc.
Determination of colorcurve colour atlas sample deviation and comparison with NCS, DIN and OSA‐UCS atlas sample deviation
Authors: Smith N. S.
Published: June 2007

This article presents an evaluation of the deviation of the Colorcurve atlas samples from their designated aim points. Sample deviations are evaluated in terms of hue, chroma, and lightness. In addition, the deviation of the Colorcurve samples from their respective aim points are graphically represented for eighteen lightness levels, Comparison is provided with NCS, DIN, and OSA‐UCS atlas sample deviation.
Comparison of colorimetric and spectrophotometric algorithms for computer match prediction
Authors: Sluban Boris
Published: June 2007

The article discusses two types of colour‐formulation strategies: the tristimulus colorimetric strategy (ΔX,ΔY,ΔZ) → (0,0,0) and the least‐squares curve fitting Σjw2j[ΔR(λj)]2 → min. Then a new matching strategy (ΔED65)2 + (ΔEA)2 + (ΔEWWF)2 → min is stated, which tries to combine the advantages of the first two strategies: more “balanced” colour differences for several different illuminants (the case of curve fitting) and small colour differences for the illuminant involved in the matching process (the case of tristimulus matching). An algorithm following this new general strategy is constructed using the case of single‐constant Kubelka‐Munk theory as an example. Results of a few numerical experiments are included for illustration.
Colorcurve and coloroid notations for the OSA‐UCS atlas samples
Authors: Smith N. S.
Published: June 2007

Colorcurve (D65/1964) and Coloroid (C/1931) notations of the 558 OSA‐UCS atlas samples are presented in two tables. One table provides the Colorcurve and Coloroid notations for the 424 regular samples; the other for the 134 near‐neutral (half‐step) samples. Colorcurve notations are derived from the OSA‐UCS aim points, and Coloroid notations are derived from colorimetric data of the OSA‐UCS samples contained in MacAdam's copy of the OSA‐UCS colour atlas.
Measuring color‐matching functions. Part I
Authors: North Amy D. , Fairchild Mark D.
Published: June 2007

A visual colorimeter was designed to implement a new model for the determination of color‐matching functions developed in the Munsell Color Science Laboratory. An instrument utilizing laser primaries was originally developed. The instrument was later improved to incorporate CRT primaries and seven interference filters to make matches to simulated daylight in a 2° bipartite field. The system was designed to minimize the strain on observers. Color‐matching functions of naïve observers can be measured in approximately 30 minutes. Results from an individual observer correlate well with data collected on the National Research Council of Canada's Trichromator. Part II of this article gives the color‐matching functions results for 18 observers and 20 repetitions by a single observer.
Illuminance dependency of L/Y (lightness/luminance‐factor)‐ratio effect
Authors: Nayatani Yoshinobu , Sobagaki Hiroaki , Hashimoto Kenjiro
Published: June 2007

Using a modified model for predicting the perceived lightness of chromatic object colors for various adapting illuminances, the following two kinds of predictions were done for seven illuminance levels from 2 to 3000 lx on the basis of the Wysecki data. One concerned the contour lines of equal L/Y (lightness/luminance‐factor) ratios in the whole chromaticity gamut, and the other the values of L/Y ratios for spectral colors. All the colors predicted have tristimulus value Y = 20. The computed results confirmed that the difference of L/Y‐ratio effect found between the Wysecki and the Sanders‐Wyszecki experiment was caused by the difference of the test adapting illuminance between them.
Image color‐appearance specification through extension of CIELAB
Authors: Fairchild Mark D. , Berns Roy S.
Published: June 2007

An extension of the CIE 1976 (L*, a*, b*) color space, CIELAB is described for applications in color reproduction. This extension incorporates a more accurate model of chromatic adaptation, capability to distinguish between the modes of appearance of reflective and self‐luminous stimuli, and adjustments to account for changes in surround. The extension of CIELAB is referred to as the RLAB color space. This color space can be used for calculating metrics of lightness, chroma, hue, and color difference. It can also be used to determine the required colors for reproduction across changes in media and viewing conditions. A pilot experiment testing the RLAB model for cross‐media color reproduction is also described.
Quantifying colour appearance. part IV. Transmissive media
Authors: Luo M. Ronnier , Gao X. Wang , Rhodes Peter A. , Xin H. John , Clarke Anthony A. , Scrivener Stephen A. R.
Published: June 2007

The experimental data from this study extends the LUTCHI colour‐appearance data to cover transmissive media. Two further experiments were carried out: one used a large cut‐sheet transparency viewed using a back‐lit illuminator, and another used a 35‐mm slide projected onto a white screen. These new data were used to reveal the changes in colour appearance caused by different viewing parameters studied, and to evaluate the predictive accuracy of five uniform colour spaces and colour‐appearance models. The results show that Hunt's 91 model (developed to fit earlier experimental results) did not perform as well as it did in the previous studies using nontransmissive media. This implies that there are large differences in perceived colour appearance between transmissive and nontransmissive media viewing conditions. Some modifications were subsequently made to Hunt's 91 model and the predictive accuracy was greatly improved.
Problems connected with the concept of gloss
Authors: Sève Robert
Published: June 2007

A summary of the most recent ideas about gloss is presented with specific attention to the problems raised by the evaluation of perceived gloss with physical quantities. Research work published on the problem of multidimensionality of gloss, as well as methods using several parameters to characterize gloss, are first mentioned. Then physical phenomena related to gloss are discussed from the points of view of physical optics, geometrical optics, and photometry. Experimental results are related to the theory. It is shown that a mirror element reflects light in such a way that its radiant intensity in the specular direction is independent of its area, contrary to the radiant intensity scattered by an isotropic diffuser. The consequences of this fact for the current measurement of gloss are developed, mainly, the arbitrary choice of any gloss scale. A proposal is made to relate the measured gloss to the luminance factor in the specular direction. Problems raised by the terminology are also discussed: terms are needed for the general phenomenon of gloss, for the perceptual aspect of gloss, and for the most widely measured photometric quantity related to gloss. Proposals for future work are made.
Objective evaluation of color design. II
Authors: Kawamoto Naoki , Soen Toshiichi
Published: June 2007

A method to predict psychological values of color design was derived from our experimental data on 30 random color patterns previously published. This method, based on the two‐dimensional Fourier transform of color patterns, was designed to evaluate psychological values of the pattern in terms of 13 rating scales such as “beautiful‐ugly,” “warm‐cold,” “hard‐soft,” and so on. It was found that the psychological values of random color patterns could be evaluated in terms of zero‐frequency (average color) and low‐, medium‐, and high‐frequency components of the Fourier transform of the patterns. Applicability of the evaluation method to predict psychological impressions of real color design was tested with results from a new experiment on some fabric design that is described in this article.
Color‐rendering capacity of light
Authors: Xu H.
Published: June 2007

Two types of questions, both related to color‐rendering properties of light, can be identified. Type A: Given a spectral reflectance chip under illumination of a certain spectral power distribution, What color can appear? Does the appearing color, in comparison with a reference one, look right or distorted? Type B: Given a great many chips of different spectral reflectance functions under illumination of a certain spectral power distribution, How many different colors, no matter what colors, can appear? Are there a great many different colors or just a few different colors appearing? Questions of type A reflect an important aspect of color‐rendering properties and can be tackled with an established measure, the CIE color‐rendering index. Questions of type B, related to quite another aspect of color‐rendering properties, have particular relevance when illumination's function of making things visible is of most concern. This article discusses a new measure, the color‐rendering capacity (CRC), developed for dealing with questions of type B, and explains the measure's derivation, calculation, and implications.
Categorized color space on CRT in the aperture and the surface color mode
Authors: Shinoda Hiroyuki , Uchikawa Keiji , Ikeda Mitsuo
Published: June 2007

The study was made for structure of categorized color space in the aperture and the surface color modes. The color appearances of two modes were reproduced on a CRT display with or without a surround configuration. Subjects made categorical color naming with 11 basic color terms. The (x,y,L) color space divided with these terms showed structural difference between the two modes. This result indicates that color is categorized by only chromaticity in the aperture color mode but by luminance and chromaticity in the surface color mode. © 1993 John Wiley & Sons, Inc.
On obtaining shape from color shading
Authors: Petrov A. P.
Published: June 2007

Color and Grassmann‐Cayley Coordinates of Shape are considered in this article. The image irradiance equation for colored surfaces and the Grassman manifold λ of orbits Q = {B · h + c; detB ≠ 0} Where c is a vector sweeping the color space H, B is a 3 × 3 matrix, and h(x, y) is the color image of a Lambertian surface assumed to be a linear vector‐function of the normal vectors. Different orbits Q(n) correspond to different shapes but they are invariant under color and illuminant transformation. Coordinates of an orbit Q in λ can be computed as 3 × 3 (2 × 2, sometimes) determining the elements of which are values of some linear functionals (receptive fields) of h(x, y). Based on the approach, a shape‐from‐shading algorithm was developed and successfully tested on the threeband color images of various real objects (an egg, cylinders and cones made of paper, etc.). © 1993 John Wiley & Sons, Inc.
Intersections of matching spectra: Applications
Authors: Thornton William A.
Published: June 2007

Results of the preceding article are used to develop (1) a “characteristic” SPD of a light; (2) a method of spectral correction to remove the simple color difference in a pair of lights or reflectances that embody both metamerism and simple color difference; (3) characterization of typical spectral differences between SPDs of lights that match; and (4) a definition and procedure for specifying “degree of metamerism” of a pair of matching lights or reflectances. © 1993 John Wiley & Sons, Inc.
Lightness and reflectance of munsell gray samples
Authors: Xu H.
Published: June 2007

A procedure has been designed, on the basis of the general‐type luminance difference threshold data, to find the maximum possible number of the distinguishable luminance levels (the MAX‐NUM‐OF‐LEVELS) between two given luminances with respect to observers under a certain adaptation state. Taking the MAX‐NUM‐OF‐LEVELS as a measure of visibility and applying the procedure to a study of lightness and reflectance of gray samples, it is found that the existing Munsell gray samples with Munsell values 1 to 9, which intend to appear equally spaced, can hardly be regarded as equally‐spaced in lightness, and a group of rearranged reflectances for these gray samples may improve the situation. © 1993 John Wiley & Sons, Inc.
Fuzzy set theory on car‐color design
Authors: Hsiao Shih‐Wen
Published: June 2007

The relationship between some colors of cars and their image sensation are investigated by using the fuzzy set theory. The color image a person has of a car is quantified using the membership function. A computer program is constructed to calculate and analyze the similarity relations of various colors and further to arrange the corresponding membership functions of colors to one image word by size. The results show that the man‐machine matching in color image is mostly dominated by the hue. The orderly table can be suggested to the designer for what color should be used if he can input the demanded image word (or words) for specifying the characteristic of a car in the stage of concept design. In such a way, not only can the error of a design decision be reduced, but the efficiency of the decision making can also be improved. Thus, it is indeed a powerful and valuable method for designing a product.
Modified CIELAB formula tested using a textile pass/fail data set
Authors: Witt Klaus
Published: June 2007

The proposed new color‐difference formula of CIE TC 129, which is a modified version of CIELAB, was tested with a recently published data set of textile pass/fail judgments. Goodness of fit is improved, if the parameter of lightness is set near 2, and if, additionally, a weight function for lightness is defined that reduces the weight of a lightness difference with lightness level in relation to chroma or hue scaling. © 1994 John Wiley & Sons, Inc.
Dichromatic reflection models for a variety of materials
Authors: Tominaga Shoji
Published: June 2007

This article proposes dichromatic reflection models adequate for describing surface‐spectral reflectances of a variety of materials. the standard dichromatic reflection model for inhomogeneous materials assumes that light reflected from an object's surface is decomposed into two additive components: the body reflection and the interface reflection, which is independent of wavelength. First, we present a method for testing the adequacy of this standard model based on the observations of surface‐spectral reflectances. the standard dichromatic reflection model is adequate for many materials. However, the test results point out that there are some cloths for which the standard model is inadequate, and metals that have only the interface reflection. Next, we extend the standard model to have an interface reflection component that depends on wavelength. an algorithm is presented for estimating two reflectance functions in the generalized model. Moreover, a dichromatic reflection model specialized for only the specular reflection is defined for approximating metal's reflection. the reflection characteristics are analyzed using a chromaticity diagram. It is concluded that surfacespectral reflectances of most materials are described by three types of the dichromatic reflection model. © 1994 John Wiley & Sons, Inc.
Spatial integration with chromatic stimuli in dichromatic vision
Authors: Kawabata Yasuhiro
Published: June 2007

The critical area of spatial integration was examined in dichromatic vision (protanope and deuteranope) by means of chromatic thresholds at equiluminance. The results showed that the critical area became smaller as the chromatic saturation of the background field was increased. Here, the chromatic saturation was defined by the colorimetric purity of the background field, multiplied by the saturation coeficient (Cs) of each dominant wave‐length. For the 470‐nm field condition, the trend of dichromatic data was similar to that of the previous data with normal subjects. For the 590‐nm condition, however, the decrease of integration area was less than that of the normal. This discrepancy can be attributed to the diference of saturation coeficients between normals and dichromats. © 1994 John Wiley & Sons, Inc.
Assessment of whiteness and tint of fluorescent substrates with good interinstrument correlation
Authors: Griesser Rolf
Published: June 2007

White is primarily a sensation like blue, green, or red and, as such, is not measurable directly. Only a physical property, the spectral reflectance of a sample, can be measured directly. But this is not a standard, fixed quantity; it depends on a number of individual properties of the measuring instrument used. the entire geometry of the illuminating chamber—generally speaking a sphere is used for samples with a structured surface—is incorporated in the measuring results. the size of the aperture and the exclusion or inclusion of gloss also influence reflectance. High whiteness is obtainable only with the aid of fluorescent whitening agents [FWAs], and is hence a fluorescent color, which demands specific qualities of the illumination. the sample illumination must be identical with that for which the colorimetric values have been calculated. Nowadays, however, this is usually standard illuminant D65, which can be simulated only approximately in measuring instruments. In addition, all lamps used are subject to changes in spectral energy distribution. the problem is how to obtain constant, comparable results, namely whiteness, tint, and lightness for fluorescent materials using measuring instruments of different designs incorporating different means of simulating standard illuminant D65 or other D illuminants. This article presents a method that has been in use in industry for about 20 years. the method in question comprises two parts: first, on the hardware side, sample illumination that has to meet specific requirements, match the UV excitation required, and remain stable; second, on the software side, the two critical dimensions of whiteness and tint are calculated indirectly from the measuring results. Only in this way is it possible to achieve a large measure of comparability between different instruments. In principle, the method is also suitable for different illuminants and for any white preference. In all other methods of assessment the parameters are not matched to the instrument characteristics. If the results obtained with different measuring instruments are to be compared, difference values have to be used, entailing the need for standards and involving all the drawbacks associated with them.
Effects of observer metamerism in the determination of human color‐matching functions
Authors: Rich Danny C. , Jalijali Jocelyn
Published: June 2007

This article addresses the results of the recent North and Fairchild article on observer metamerism. It reports on the results of a different experiment that produced similar results to those of North and Fairchild. The history of observer metamerism is outlined briefly and some possible sources of the large variations in inter‐observer matches are suggested. Finally, a plea for a commercially viable special index of metamerism for change in observer is formulated. © 1995 John Wiley & Sons, Inc.
Results of the ASTM field test of tristimulus weighting functions
Authors: Fairman Hugh S.
Published: June 2007

In 1993, the American Society for Testing and Materials carried out a field test of newly calculated tristimulus weighting factors. These weighting factors had been calculated by a method proposed by Venable. the test also included a method of correction for bandpass dependence put forth by Stearns. the purpose of the trial was to assess the possible reduction in bandpass dependence introduced by each of these sets of weights. A large number of sets of spectral data were gathered from the cooperators in the field test. Results of integration by the various sets of tristimulus weighting factors were calculated. A total of 15 120 color differences were calculated and statistics were derived to test the probable error resulting from each method of correction. Errors attributable to bandpass dependence were on the order of a few tenths to as much as one CIELAB unit when uncorrected weight sets were used. These errors could be reduced to a few hundreths of a CIELAB unit, and in some cases to a few thousandths of a unit, by employing one correcting strategy or the other. an overall mix of strategies was ultimately chosen to minimize the bandpass dependence over the entire range of weight sets. Utilizing this mixed strategy, the median error introduced into 10‐nm integration by bandpass dependence was only 0.004 CIELAB units. © 1995 John Wiley & Sons, Inc.
Automotive color certification
Authors: Longley William V.
Published: June 2007

Because of the subjective nature of determining visual color‐match acceptability, we have for many years hoped that color measurement would provide objectivity for clear‐cut decisions. Despite impressive advances in spectrophotometers and computer software, few produceruser programs have been successful using only numerical data and with no visual override. Most companies “accumulate data” but make final decisions visually. Considering the many observers making color‐match decisions at color producer sites, molding plants and assembly plants, Ford set out to establish a plan for fully objective analysis. While developing the plan, certain guidelines became critical to good correlation of visual to measured data. A pilot program is described in which the resin producers certify batches of color concentrate or precolored resin as meeting certain measured criteria. the parts are then molded and installed in vehicles and are not challenged visually but are monitored for the record. Good color match quality has resulted. © 1995 John Wiley & Sons, Inc.
Predicting the colour of trichromatic prints
Authors: Kulube Herbert M. , Hawkyard Chris J.
Published: June 2007

The colour resulting from the partial overlap of tiny dots of cyan, magenta, and yellow inks in a matrix is difficult to predict. A method of simulating it on the macro‐scale has been devised by measuring discs with coloured sectors using a spectrophotometer. Here the separate colours are mixed within the integrating sphere of the instrument. Although subtractive mixing occurs where colours overlap, the overall result to the eye/brain is interpreted by additive means. The result of mixing known areas of coloured surfaces additively was predicted successfully by Maxwell in the last century. His method, combined with the use of the CIE System, has been successfully used to predict the coordinates of the mixture of coloured sectors measured on the spectrophotometer. The theoretical model developed applies to trichromatic or polychromatic printing, whatever the substrate. © 1995 John Wiley & Sons, Inc.
Visibility of durable fluorescent materials for signing applications
Authors: Burns David M. , Pavelka Lee A.
Published: June 2007

Increasing visual complexity in the roadway environment is making the task of driving a greater challenge for the motorist. Recent advances make it possible to produce fluorescent retroreflective materials suitable for long‐term outdoor signing applications. This article presents the results of a field study investigating the relative advantage of fluorescent colors over standard colors for detection, color recognition, and conspicuity against a complex dark background. These fluorescent retroreflective materials are detected with higher frequency, and recognized with greater accuracy at further distances than the corresponding standard highway colors. They also have greater attention‐getting properties (more conspicuous) during daylight than the corresponding standard highway colors. The luminance contrast ratio of the sample to the camouflage background appears to correlate with the visibility/conspicuity results obtained in this study, particularly within a given color series. © 1995 John Wiley & Sons, Inc.
Adaptation of CIELAB CMC Acceptability Formulase to the Problem of Metamerism ( a 3‐Light Special Index of Metamerism)
Authors: Carstensen Lawrence D.
Published: June 2007

I have used the metamerism equation for the past two years on hundreds of colors. I have found the equation's agreement with visual evaluation to be a useful tool in color‐matching situations. I would appreciate any feedback on the use of this equation. I can be reached at (614) 297‐6138 or fax your comments to (614) 297‐2912.
A general form of color difference formula based on color discrimination ellipsoid parameters
Authors: Cui Chengwu , Hovis Jeffery K.
Published: June 2007

A general color difference formula has been derived based on the parameters of color discrimination ellipsoids in the CIE 1976 L*a*b* color space. By using different orders of approximation, the general formula resembles the basic forms of the current formulae. The method described in this article suggests a framework for modifying the CIE 1976 L*a*b* color difference formula.
A systematic method for color planning in product design
Authors: Hsiao Shih‐Wen
Published: June 2007

A quantitative approach for color planning in product design is addressed in this article. the color image that a product has is quantified by using the membership function of a fuzzy set. the color plan for designing an ice shaver is used as an example to show the procedure. the Hue and Tone System and the Color Image Scale are used to transform colors into images or images into colors. the composite operation for fuzzy sets is used to simulate a color projection technique to get the semantic equivalence of words and colors. A computer program is built to get the membership functions between the colors and image words. the membership functions are arranged by size and suggested to the designer to help make a decision on what color should be used. In this manner, the psychology of customers can easily be captured by the designer, consequently increasing the efficiency of the decision process. Though a simple product is taken as an example here, this systematic method can be used to design other more complicated products. In addition, the results can be used to investigate the color psychology.
The colour sensitivity of a colour matching recipe
Authors: Sluban Boris , Nobbs James H.
Published: June 2007

The article examines the concepts of the following three quantities: partial colour sensitivity of a recipe to a particular colorant, colour balance of a recipe, and the overall colour sensitivity and the related property of colour robustness of a recipe. the way to calculate numerical estimates of the above quantities is extended from the case of CIE L *a*b* to the case CMC(l:c) colour difference formula. Results of a few numerical experiments are included for illustration and some possible practical consequences are discussed.
Anomalies in additive colour matches
Authors: Ábrahám Gy , Körösi H. , Schanda J. , Shapiro A. G. , Wenzel K.
Published: June 2007

W.A. Thornton [W. A. Thornton, Toward a more accurate and extensible colorimetry, Parts I–III, Color Res. Appl. 17, 79–122, 162–186, 240–261 (1992).] reported significant discrepancies in Maxwell colour matches when using different sets of primary lights. His experiments were performed by a small, mainly older group of observers. the aim of this investigation was to test these findings over wider age ranges. We matched a broad‐band white light of constant luminance with two sets of three monochromatic primaries. These sets were similar to Thornton's AP set (497, 579, and 653 nm) and Thornton's PC set (452, 533, and 607 nm). Thirty‐two observers performed the tests with 10° fields. the chromaticities of the matches made with the AP set had a large variance and were centered around the chromaticity of the reference white. the chromaticities of the PC‐primary matches were clustered closely together and were centered at a point significantly different from the chromaticity of the reference white. the magnitudes, but not the directions, of the dispersions of the matching chromaticities were consistent with age related changes in the spectral transmission of the lens.
Abnormal Hue‐Angle change of the gemstone tanzanite between CIE illuminants d65 and a in CIELAB color space
Authors: Liu Yan , Shigley James , Fritsch Emmanuel , Hemphill Scott
Published: June 2007

The blue‐to‐purple color appearance change observed in some rare specimens of the gemstone tanzanite between daylight and incandescent light is contrary to the hue‐angle change calculated between CIE illuminants D65 and A in CIELAB color space. This abnormal calculated hue‐angle change for tanzanite can be corrected by using the spectral sensitivity functions of the three kinds of cone photoreceptors to directly calculate color. This study suggests that the cone spectral sensitivity functions are more fundamental in color calculations than the CIE color‐matching functions.
Sample‐independent color rendering index
Authors: Xu H.
Published: June 2007

The Sample‐Independent Color Rendering Index (CRI) is a measure that is independent of the choice of test color samples and that can be used for assessing one important aspect of color‐rendering properties of illumination, the aspect of accuracy of color rendering in a broad sense. This Sample‐Independent CRI works by measuring the degree of conformity between the maximum color solid attainable under a test illuminant and that under a reference illuminant. the derivation of the Sample‐Independent CRI, the calculation procedure involved, and some calculated results are presented.
Various chromatic‐adaptation transformations tested using new colour appearance data in textiles
Authors: Kuo Wen‐Guey , Luo M. Ronnier , Bez Helmut E.
Published: June 2007

A new set of colour appearance data was obtained from a series of experiments in which 240 wool samples having a large size of 3 x 3 in. square that subtends 10° at the observer's eye, and covering a large colour gamut were used. Each colour was assessed by a panel of five observers using a magnitude estimation method under three light sources, D65, TL84, and A. In total, 10,770 estimations were made, and these form a set of new colour appearance data in textiles. Data analysis was carried out and shows that the accuracy of the visual results for different observers is quite good. the colour appearance data were used to test the performance of seven chromatic‐adaptation transformations, i.e., BFD, Bartleson, von Kries, CIE, Hunt, CIEL*a*b*, and Fairchild. the results show that the BFD transformation gives the most accurate prediction to the visual results between all transformations studied. All transformations can have a better fit to the experimental grid under TL84 than that under A. However, the results given by the best chromatic‐adaptation transformation are still unsatisfied in colour industries, especially in the textile industry. the two sets of experimental grids respectively derived from this work and by Luo et al. (1991) were also studied. an expected difference between the two sets of experimental grids was found. the difference may mainly result from two factors: the experimental method in assessment and the size of the samples. © 1995 John Wiley & Sons, Inc.
Considerations on the calibration of color displays assuming constant channel chromaticity
Authors: Jiménez Barco L. Del , Díaz J. A. , Jiménez J. R. , Rubiño M.
Published: June 2007

To calibrate a CRT color monitor, several assumptions are often made about its performance, one of the most accepted being constanel channel chromaticity. However, when the measurements are taken in a extended field of CRT screen, where it is assumed that only one primary phosphor is excited, the relative spectral radiance of the other primary phosphors that are contained in that field also contributes, if the background luminance is not zero. This contribution is greater at low levels of RGB channel stimulation and would invalidate the results obtained with calibration methods based on the hypothesis of constancy of chromaticity coordinates of RGB channels. We have studied this effect on the calibration of the CRT color monitor and, as a result, we propose a calibration that takes this effect into account. to evaluate the accuracy of the method, we have calculated color differences between the chromaticity that we wanted to reproduce and the one displayed with the CIELUV color‐difference formula, and the color tolerances with the line element of MacAdam ellipses.
Nickel Complexes Bearing 2‐(Benzimidazol‐2‐yl)‐1,10‐phenanthrolines: Synthesis, Characterization and Their Catalytic Behavior Toward Ethylene Oligomerization
Authors: Zhang Min , Zhang Shu , Hao Peng , Jie Suyun , Sun Wen‐Hua , Li Peizhou , Lu Xiaoming
Published: June 2007

A series of 2‐(benzimidazol‐2‐yl)‐1,10‐phenanthrolines and their nickel(II) complexes were synthesized and characterized by elemental and spectroscopic analysis along with single‐crystal X‐ray crystallography. X‐ray diffraction analysis revealed that complexes 1a and 6a have a six‐coordinate distorted octahedral geometry due to the coordination of solvent molecules, whereas 3a is a centrosymmetric dimer in the solid state and 5b displays a five‐coordinate distorted trigonal‐bipyramidal geometry. Upon activation with diethylaluminum chloride (Et2AlCl), high catalytic activity up to 1.27 × 107 g·mol–1(Ni)·h–1 and high selectivity for 1‐butene (90.5 %) could be achieved. A higher activity up to 3.95 × 107 g·mol–1(Ni)·h–1 was observed in the 7a/Et2AlCl system with addition of 20 equiv. of PPh3 as an auxiliaryligand. Reaction conditions and the ligand environmentsignificantly influenced the catalytic properties of the complexes.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Improved seismic hazard model with application to probabilistic seismic demand analysis
Authors: Bradley Brendon A. , Dhakal Rajesh P. , Cubrinovski Misko , Mander John B. , MacRae Greg A.
Published: June 2007

An improved seismic hazard model for use in performance‐based earthquake engineering is presented. The model is an improved approximation from the so‐called ‘power law’ model, which is linear in log–log space. The mathematics of the model and uncertainty incorporation is briefly discussed. Various means of fitting the approximation to hazard data derived from probabilistic seismic hazard analysis are discussed, including the limitations of the model. Based on these ‘exact’ hazard data for major centres in New Zealand, the parameters for the proposed model are calibrated. To illustrate the significance of the proposed model, a performance‐based assessment is conducted on a typical bridge, via probabilistic seismic demand analysis. The new hazard model is compared to the current power law relationship to illustrate its effects on the risk assessment. The propagation of epistemic uncertainty in the seismic hazard is also considered. To allow further use of the model in conceptual calculations, a semi‐analytical method is proposed to calculate the demand hazard in closed form. For the case study shown, the resulting semi‐analytical closed form solution is shown to be significantly more accurate than the analytical closed‐form solution using the power law hazard model, capturing the ‘exact’ numerical integration solution to within 7% accuracy over the entire range of exceedance rate. Copyright © 2007 John Wiley & Sons, Ltd.