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1.
In a previous work, the authors reported on the results of a color naming experiment performed on native Italian speakers regarding the location of focal colors and centroids in the Uniform Color Scales of the Optical Society of America color system. That work was aiming at comparing such data with those previously obtained by Boynton and Olson (B&O) accounting for the differences in the paradigm and the language. The number of consistency and consensus colors in the different lightness plans was also reported but no information was provided on their placement. Though, such information is very important for any subsequent modeling stage. The objective of this article is to fill such a gap and share such data with the scientific community to provide a reference database for future investigation. Three different datasets were considered: the extended OSA (E‐OSA), the reduced OSA (R‐OSA), and the B&O's (B&O) sets of reference colors. Results show a good overlap among the locations of the consensus colors in the {L, j, g} color model between B&O and the subset of E‐OSA colors overlapping with the B&O 424 colors (R‐OSA), as well as a strong agreement on consistency. Furthermore, a close proximity among the centroids of homologue regions for the majority of the classes was found. © 2012 Wiley Periodicals, Inc. Col Res Appl, 38, 437–447, 2013 相似文献
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Tarow Indow 《Color research and application》1999,24(4):266-279
The size of perceptual difference of colors (j, k) is scaled as djk by selecting a pair of Munsell grays in which the lightness difference matches in size with the color difference. Hence, d is given in terms of Munsell V. The degree of principal hue component α in a color j is scaled as ξα(j) by making marks on a line segment and the range of ξα is from 0 to 10. By plotting ξα(H V/C) on Munsell H‐circle, principal hue curves ξ¯α(H V/C) are defined, where α = R, Y, G, B, V = 4–7, and C = 2–10. In this process, similar plots of NCS codes (cϕα) are used as references. The curves ξ¯α(H V/C) tell us the appearance of Munsell colors (H V/C) and also enable us to predict color differences. The relationship between djk and ΔV = |Vj − Vk|, Δξ¯α = |ξ¯α(Hj Vj/Cj) − ξ¯α(Hk Vk/Ck)| is tested in various ways, e.g., logarithmic, power, Minkowski‐type functions. The best predictor d̃ is given by a simple linear form, d̃ = aVΔV + {d0 + ΣaαΔξ¯α}. For 899 pairs (j, k), 706 differing in H, C and 193 differing in H, V, C, aV = 0.459, d0 = 0.610, aR = 0.199, aY = 0.031, aG = 0.098, aB = 0.136, and the root‐mean‐squares of (djk − d̃jk) is 0.338 in the matched V‐unit. © 1999 John Wiley & Sons, Inc. Col Res Appl, 24, 266–279, 1999 相似文献
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Peter Bodrogi Stefan Brückner Nathalie Krause Tran Quoc Khanh 《Color research and application》2014,39(3):252-262
A series of visual experiments were carried out to rate the similarity of color appearance of two color stimuli on categorical and continuous semantic rating scales. Pairs of color stimuli included two copies of the same colored real or artificial object illuminated by a test light source and a reference light source. A formula was developed to predict a category of color similarity (e.g., “moderate” or “good”) from an instrumentally measured color difference. Given a numeric value of a color difference between the two members of a pair of colors, for example, 2.07, the formula is able to predict a category of color similarity, for example, “good.” Because color‐rendering indices are based on color differences, the formula could be applied to interpret the values of the new color‐rendering index (n‐CRI or CRI2012) in terms of such semantic categories. This semantic interpretation enables nonexpert users of light sources to understand the color‐rendering properties of light sources and the differences on the numeric scale of the color‐rendering index in terms of regular language. For example, a numeric value of 87 can be interpreted as “good.” © 2013 Wiley Periodicals, Inc. Col Res Appl, 39, 252–262, 2014; Published online 14 March 2013 in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/col.21798 相似文献
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Riemannian metric tensors of color difference formulas are derived from the line elements in a color space. The shortest curve between two points in a color space can be calculated from the metric tensors. This shortest curve is called a geodesic. In this article, the authors present computed geodesic curves and corresponding contours of the CIELAB ( ), the CIELUV ( ), the OSA‐UCS (ΔEE) and an infinitesimal approximation of the CIEDE2000 (ΔE00) color difference metrics in the CIELAB color space. At a fixed value of lightness L*, geodesic curves originating from the achromatic point and their corresponding contours of the above four formulas in the CIELAB color space can be described as hue geodesics and chroma contours. The Munsell chromas and hue circles at the Munsell values 3, 5, and 7 are compared with computed hue geodesics and chroma contours of these formulas at three different fixed lightness values. It is found that the Munsell chromas and hue circles do not the match the computed hue geodesics and chroma contours of above mentioned formulas at different Munsell values. The results also show that the distribution of color stimuli predicted by the infinitesimal approximation of CIEDE2000 (ΔE00) and the OSA‐UCS (ΔEE) in the CIELAB color space are in general not better than the conventional CIELAB (ΔE) and CIELUV (ΔE) formulas. © 2012 Wiley Periodicals, Inc. Col Res Appl, 38, 259–266, 2013 相似文献
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Changjun Li Zhiqiang Li Zhifeng Wang Yang Xu Ming Ronnier Luo Guihua Cui Manuel Melgosa Michael H. Brill Michael Pointer 《Color research and application》2017,42(6):703-718
The CIECAM02 color‐appearance model enjoys popularity in scientific research and industrial applications since it was recommended by the CIE in 2002. However, it has been found that computational failures can occur in certain cases such as during the image processing of cross‐media color reproduction applications. Some proposals have been developed to repair the CIECAM02 model. However, all the proposals developed have the same structure as the original CIECAM02 model and solve the problems concerned at the expense of losing accuracy of predicted visual data compared with the original model. In this article, the structure of the CIECAM02 model is changed and the color and luminance adaptations to the illuminant are completed in the same space rather than in two different spaces, as in the original CIECAM02 model. It has been found that the new model (named CAM16) not only overcomes the previous problems, but also the performance in predicting the visual results is as good as if not better than that of the original CIECAM02 model. Furthermore the new CAM16 model is simpler than the original CIECAM02 model. In addition, if considering only chromatic adaptation, a new transformation, CAT16, is proposed to replace the previous CAT02 transformation. Finally, the new CAM16‐UCS uniform color space is proposed to replace the previous CAM02‐UCS space. A new complete solution for color‐appearance prediction and color‐difference evaluation can now be offered. 相似文献
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Rolf G. Kuehni 《Color research and application》2000,25(2):123-131
Five color order systems (Munsell Renotations, Munsell Re‐renotations, OSA‐UCS, NCS, and Colorcurve) have been compared by optimizing the powers applied to individual opponent‐color functions. The results indicate general similarities in that powers applied to the red and green functions tend to be closer to 1, while those applied to the blue function and the yellow function are generally smaller. Specifically, there are many individual differences that make each system unique. The results inspire confidence in the veracity of the opponent‐color system methodology. © 2000 John Wiley & Sons, Inc. Col Res Appl, 25, 123–131, 2000 相似文献
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The present study investigated Italian basic color terms (BCTs). It is an extension of our previous work that explored Italian basic color categories (BCCs) using a constrained color‐naming method, with 11 Italian BCTs allowed, including blu for naming the BLUE area. Since a latter outcome indicated a categorization bias, here monolexemic color‐naming method was employed, enabling also use of azzurro, deeply entrenched Italian term that designates light blue. In Experiment 1, colors (N = 367), sampling the Munsell Mercator projection, were presented on a CRT; color names and reaction times of vocalization onset were recorded. Naming consistency and consensus were estimated. Consistency was obtained for 12 CTs, including the two blue terms; consensus was found for 11 CTs, excluding rosso “red.” For each consensus category, color with the shortest response time was considered focal. In Experiment 2, consensus stimuli (N = 72) were presented; on each trial, observers indicated the focal color (“best example”) in an array of colors comprising a consensus category. For each of the 12 Italian CCs, centroid was calculated and focal color (two measures) estimated. Compared to English color terms, two outcomes are specific to Italian color naming: (i) naming of the RED‐PURPLE area is highly refined, with consistent use of emergent non‐BCTs; (ii) azzurro and blu both perform as BCTs dividing the BLUE area along the lightness dimension. The findings are considered in the framework of the weak relativity hypothesis. Historico‐linguistic, environmental, and pragmatic communication factors are discussed that conceivably have driven the extension of the BCT inventory in Italian. © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 402–415, 2016 相似文献
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The Optical Society of America Uniform Color Scales (OSA‐UCS) possesses many salutary properties, but it is presently under‐utilized. The authors believe the reason may be that the transformation from CIE notation to the OSA system presently has no known inverse. In an effort to rectify that lack, the OSA system is presented in its forward transformation, and then an inverse transformation using a Newton–Raphson iterative algorithm is described. The authors' experience with parameters associated with implementing the algorithm is related, and a few worked examples are provided to assist potential users in their implementation. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2011 相似文献
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Psychophysical experiments of color discrimination threshold and suprathreshold color‐difference comparison were carried out with CRT‐generated stimuli using the interleaved staircase and constant stimuli methods, respectively. The experimental results ranged from small (including threshold) to large color difference at the five CIE color centers, which were satisfactorily described by chromaticity ellipses as equal color‐difference contours in the CIELAB space. The comparisons of visual and colorimetric scales in CIELAB unit and threshold unit indicated that the colorimetric magnitudes typically were linear with the visual ones, though with different proportions in individual directions or color centers. In addition, color difference was generally underestimated by the Euclidean distance in the CIELAB space, whereas colorimetric magnitude was perceptually underestimated for threshold unit, implying the present color system is not a really linear uniform space. Furthermore, visual data were used to test the CIELAB‐based color‐difference formulas. In their original forms CIEDE2000 performed a little better than CMC, followed by CIELAB, and with CIE94 showing the worst performance for the combined data set under the viewing condition in this study. © 2002 Wiley Periodicals, Inc. Col Res Appl, 27, 349–359, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10081 相似文献
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Retroreflective markings on clothing and carried articles can enhance the safety of pedestrians in traffic at night, and the use of color can contribute to the appeal of such markings. Based on experimental work on conspicuity judgment of chromatic vs. achromatic markings, conspicuity is interpreted in terms of color difference from black in uniform color space. © 1996 John Wiley & Sons, Inc. 相似文献
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Tarow Indow 《Color research and application》2002,27(6):425-429
A relationship between assessed color differences and assessed components of colors is presented. The perceptual difference between colors j and k is converted to a lightness difference of two Munsell grays, VA and VB, and djk = |VA ? VB|. Scaled values of principal hue components of a color ξ α(H|V/C), α = R, Y, G, and B, are read from charts based on assessments of observers. Previous charts (Color Research and Application, 1999, 24, 266–279) are enlarged and extended. A linear combination of ΔV = |Vj ? Vk| and Δξ α = |ξ α(Hj|Vj/Cj) ? ξ α(Hk|Vk /Ck)|, d?jk, is the best to predict djk. The root‐mean‐squares of (djk ? d?jk) is 0.34 V, about one third of the lightness difference from V to V + 1 on the Munsell Value Scale. 相似文献
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Rolf G. Kuehni 《Color research and application》2008,33(1):5-9
Some 100 years before Albert Munsell developed his color order system, French silk merchant and inventor of a technology for producing works of art in silk velours, Gaspard Grégoire, introduced a color order system based on the color attributes hue, (relative) chroma, and lightness. Conceived in the mid‐1780s, an atlas with 1350 samples was produced before 1813 and found use in French Royal manufacturing operations and educational institutions. It was followed a few years later by one with 343 samples. Grégoire's work was subsequently overshadowed by Michel‐Eugene Chevreul's more complicated and less intuitive hemispherical system of 1839. © 2007 Wiley Periodicals, Inc. Col Res Appl, 33, 5–9, 2008 相似文献
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A new colour rendering index, CRI‐CAM02UCS, is proposed. It predicts visual results more accurately than the CIE CIR‐Ra. It includes two components necessary for predicting colour rendering in one metric: a chromatic adaptation transform and uniform colour space based on the CIE recommended colour appearance model, CIECAM02. The new index gave the same ranks as those of CIE‐Ra in the six lamps tested regardless the sample sets used. It was also found that the methods based on the size of colour gamut did not agree with those based on the test‐sample method. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2012 相似文献
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Binghua Chai Ningfang Liao Dazun Zhao Weiping Yang 《Color research and application》2006,31(3):218-228
In this study, we tried to consider various color appearance factors and device characterization together by visual experiment to simplify the across‐media color appearance reproduction. Two media, CRT display (soft‐copy) and NCS color atlas (hard‐copy), were used in our study. A total of 506 sample pairs of RGB and HVC, which are the attributes of NCS color chips, were obtained according to psychophysical experiments by matching soft copy and hard copy by a panel of nine observers. In addition, a set of error back‐propagation neural networks was used to realize experimental data generalization. In order to get a more perfect generalizing effect, the whole samples were divided into four parts according to different hues and the conversion between HVC and RHVCGHVCBHVC color space was implemented. The current results show that the displays on the CRT and the color chips can match well. In this way, a CRT‐dependent reproduction modeling based on neural networks was formed, which has strong practicability and can be applied in many aspects. © 2006 Wiley Periodicals, Inc. Col Res Appl, 31, 218–228, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20209 相似文献
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Relationships between suprathreshold chroma tolerances and CIELAB hue‐angles have been analyzed through the results of a new pair‐comparison experiment and the experimental combined data set employed by CIE TC 1–47 for the development of the latest CIE color‐difference formula, CIEDE2000. Chroma tolerances have been measured by 12 normal observers at 21 CRT‐generated color centers L*10 = 40, C*ab,10 = 20 and 40, and hab,10 at 30° regular steps). The results of this experiment lead to a chroma‐difference weighting function with hue‐angle dependence WCH, which is in good agreement with the one proposed by the LCD color‐difference formula [Color Res Appl 2001;26:369–375]. This WCH function is also consistent with the experimental results provided by the combined data set employed by CIE TC 1–47. For the whole CIE TC 1–47 data set, as well as for each one of its four independent subsets, the PF/3 performance factor [Color Res Appl 1999;24:331–343] was improved by adding to CIEDE2000 the WCH function proposed by LCD, or the one derived by us using the results of our current experiment together with the combined data set employed by CIE TC 1–47. Nevertheless, unfortunately, from the current data, this PF/3 improvement is small (and statistically nonsignificant): 0.3 for the 3657 pairs provided by CIE TC 1–47 combined data set and 1.6 for a subset of 590 chromatic pairs (C*ab,10>5.0) with color differences lower than 5.0 CIELAB units and due mainly to chroma. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 420–427, 2004; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/col.20057 相似文献
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Rolf G. Kuehni 《Color research and application》2000,25(3):186-192
A structural comparison has been made of the lightness, chroma, and hue scales of the Munsell system, as expressed in the Munsell Renotations, and of the OSA‐UCS system. While the lightness scales are similar (except for the adjustment for the Helmholtz–Kohlrausch effect and the inclusion of a “crispening” effect in OSA–UCS), there are significant differences in the chroma scales along the major chromatic axes. Unlike in CIELAB, the increments in X and Z along these axes for equal chroma steps in both systems do not fall on a continuous function. In the two systems, as well as in CIELAB lines connecting colors of equal chroma differences at different Y values point to nonreal origins. These differ among the three systems. A major difference between Munsell and OSA–UCS is the size of the first chroma step away from gray. An experiment has been performed with the result that the OSA–UCS system is in much better agreement with the average observer in this respect than the Munsell system. OSA–UCS exhibits considerably more internal uniformity in terms of X and Z increments between steps than the Munsell system. © 2000 John Wiley & Sons, Inc. Col Res Appl, 25, 186–192, 2000 相似文献
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The major issues of using less storage space and wanting higher transmission rates for information in the form of high quality color images was taken into consideration. Two experiments were conducted in order to investigate and compare performance of compression standard including JPEG 1992 and JPEG 2000, and a newly developed CSI‐JPEG. The CSI‐JPEG is an amalgamation of Cubic Spline Interpolation (CSI) with baseline JPEG 1992 algorithm. The performance of different image compression algorithms was evaluated using different color models/spaces in terms of compression rate, color accuracy, and visual quality. The results from three assessment methods consistently showed that JPEG 2000 and CSI‐JPEG performed significantly better compared with JPEG 1992 for small color differences (in the range of acceptability). Moreover, the CAM02‐UCS performed best among other selected models in terms of compression rate and image performance for all three image compression algorithms. The results from the visual assessment also confirmed this. It was also found that CIEDE2000 can be reliably used for assessing quality of compressed images with low levels of distortion. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 460–473, 2017 相似文献
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In this article, we report new color discrimination ellipsoids calculated from two normal observers, using a CRT device and five values of luminance at each of the five centers recommended by the CIE in 1978 (Col Res Appl 1978;3:149–151). Our main goal was to test the weighting function for lightness adopted by the CIE94 color‐difference model (CIE Publication 116, 1995). Although some of the experimental conditions employed here (CRT monitor, small size of the visual field, and controlled exposure time) did not fit those recommended by this model, our results support the weighting function for lightness proposed by CIE94. The only robust trends observed in the ellipsoids obtained were a confirmation of Weber's law and a decrease in the area of the x, y chromaticity ellipses, when the luminance of each reference stimulus increased towards the one of the surround. © 1999 John Wiley & Sons, Inc. Col Res Appl, 24, 38–44, 1999 相似文献