共查询到20条相似文献，搜索用时 15 毫秒
1.
Yoshinobu Nayatani 《Color research and application》2004,29(2):135-150
A new theoretical color order system is proposed on the basis of various studies on color appearance and color vision. It has three orthogonal opponent‐colors axes and an improved chromatic strength of each hue. The system has color attributes whiteness w, blackness bk, grayness gr, chroma C, and hue H. A method is given for determining Munsell notations of any colors on any equi‐hue planes in the system. A method is also given for determining grayness regions and grayness values on hue‐chroma planes in the system. It is concluded that colors with the same color attributes [w, gr, bk, C] but with different hues in the theoretical space have approximately the same perceived lightness, the same degree of vividness (“azayakasa” in Japanese), and also the same color tone. The tone concept, for example used in the Practical Color Coordinate System (PCCS), is clarified perceptually. The proposed system is a basic and latent color‐order system to PCCS. In addition, the concept of veiling grayness by a pure color with any hue is introduced. Further, relationships are clarified between generalized chroma c(gen) and grayness. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 135–150, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10234 相似文献
2.
3.
4.
Yoshinobu Nayatani 《Color research and application》2002,27(3):171-179
In the proposed modified opponent‐colors system, the hue regular rectangles show the chromatic coordinates of any chromatic colors better than hue circles. In the hue rectangles equihue and equichroma loci are shown together with equigrayness loci. In the color perception space of the modified opponent‐colors system, a city‐block metric must be used instead of a Euclidean one for distance. The reason for this is described in detail. The proposed color perception space constitutes a regular octahedron. © 2002 Wiley Periodicals, Inc. Col Res Appl, 27, 171–179, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10046 相似文献
5.
6.
Although gray is defined as an achromatic color sensation varying only in lightness, in practice, grayness can be tinged by any hue within a limited range of chroma. Given the fact that preferred perceived white and black are slightly chromatic, the hypothesis tested in this study is that the preferred perceived object gray is also slightly chromatic. Two psychophysical experiments were carried out to test this hypothesis. A total of 56 color normal subjects assessed 27 different gray patches that varied mainly in hue, in three separate trials. Subjects selected a subset of samples (10 in the first experiment and five in the second experiment) that were considered “most gray” resulting in 168 selected sets of samples. Subjects then ranked their selected subset of samples from most to least gray. A total of 1225 assessments were thus obtained (750 assessments in the first experiment and 465 in the second experiment). Results from both experiments were in good agreement and indicate that greenish blue grays in the range of 190° to 235° of CIELAB hue angle were selected as most gray, thus indicating that the perception of grayness is influenced by hue. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 374–382, 2015 相似文献
7.
Rolf G. Kuehni 《Color research and application》2016,41(5):439-444
The question of how many different colors humans can perceive has been of interest to philosophers, psychologists and color scientists for centuries. In recent years the question of the number of distinguishable object color stimuli has been addressed by color scientists by defining a distinguishable color as a given stimulus surrounded by the contour of stimuli just noticeably different from the central stimulus. For a particular set of conditions the number of distinguishable object color stimuli assessed in this manner has recently been found to be slightly larger than 2 million. In this article an argument is made that the related rules are arbitrary and unnecessarily limiting. Based on logical arguments and experimental just noticeable difference data it is shown that, for the conditions involved, a more realistic if conservative number of distinguishable object color stimuli is ～40 million. © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 439–444, 2016 相似文献
8.
《Color research and application》2016,41(5):540-576
In his response to the comments on his article ‘How many colors can we distinguish?’ by Flinkman and Laamanen, Kuehni points out that their suggestion for just noticeable differences to be defined as diameters rather than radii in related unit difference ellipsoids or spheres lacks the conceptual and geometric logic behind JND solids and is not valid. © 2016 Wiley Periodicals, Inc. Col Res Appl, 2016 相似文献
9.
Rolf G. Kuehni 《Color research and application》2016,41(5):522-529
M. Brill, in his comments “Maximum number of discriminable colors in a region of uniform color space,” offers a different calculation method from that used by R. G. Kuehni in “How many object colors can we distinguish?,” one based on close‐packing of just noticeable difference spheres. The number per just noticeable difference (JND) sphere is lower than that derived in Kuehni's study. Based on the resulting number of close‐packed JND spheres in the CIECAM02/D65 object color solid and Brill's described multiplier of 5.923 potential stimuli within a JND sphere, the resulting number of distinguishable color stimuli is 9.114 million. © 2016 Wiley Periodicals, Inc. Col Res Appl, 00, 000–000, 2016 相似文献
10.
This is a comment on Prof. Rolf G. Kuehni's article, How Many Object Colors Can We Distinguish? We give a reasoning why the previously calculated estimates for the number of discernible colors are valid, apart from the possible deviations caused by uncertainty of JND and non‐uniformity of color space, without correcting them with a coefficient proposed by Kuehni. © 2016 Wiley Periodicals, Inc. Col Res Appl, 2016 相似文献
11.
Michael H. Brill 《Color research and application》2016,41(5):492-512
Continuing a discussion by Kuehni, this note examines the problem of fitting as many as possible colors in a 1‐JND radius sphere such that each pair of colors is separated by at least 1 JND. Kuehni announced nine. A first estimate yields a maximum of 13, but this is too many because colors populating adjacent spheres will be too close to each other. Accordingly, I derive the maximum number, , of discriminable colors per unit volume of color space, and then formally compute from this number packing density a number of colors inside the unit sphere. That estimate, nearly 6, will undoubtedly erode when discrete color points are chosen within the unit sphere. Kuehni's estimate of 9 is too high. © 2016 Wiley Periodicals, Inc. Col Res Appl, 2016 相似文献
12.
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
13.
针对LED广告灯箱色彩变化少的问题,介绍了基于红、绿、蓝3原色调色原理,实现基于单片机AT89C52的软件控制LED调色的控制方法。硬件实验表明,电路系统简单,控制效果可靠,实现了LED的调色任务。 相似文献
14.
15.
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
16.
A quantitative evaluation method for the CIE color‐planning activity within the product design cycle is proposed in this article. The questionnaire‐based process that is traditionally employed to obtain objective color psychology tends to be time‐consuming. Accordingly, this study proposes the use of gray system theory to overcome this problem. In the CIE color system, colors are defined by three primary colors, R (red), G (green), and B (blue). Using these three principal hues with fixed equigap sequences to simulate specific basic color samples is an efficient means of investigating unicolor images on a personal computer. However, a gray relational generating operation can be used to simulate colors beyond these basic samples and to predict the corresponding membership values for semantic words. In addition, the gray clustering operation is introduced to predict the overall color image evaluation of multicolored products. The predicted evaluation results of the gray system theory and a back‐propagation neural network are both compared with experimentally verified results. The results indicate that the gray forecasting model is the more effective means of predicting the image evaluation, and therefore, the method is adopted within the color‐planning activity. Although this study takes the example of the Internet‐aided color planning of a baby walker as a case study, the proposed method can also be used on other products. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 222–231, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20009 相似文献
17.
Two color-memory experiments were performed to investigate whether observers tended to confuse colors with a smaller color difference in memory or colors in a same color-category region. We made color stimuli on a color CRT. Color difference was determined by a simultaneous color discrimination experiment. Color-category regions were obtained by a categorical color-naming experiment using the 11 basic color names: white, black, red, green, yellow, blue, brown, orange, purple, pink, and gray. The results show that two colors with a certain color difference can be confused more easily when they are in a same color category than in different color categories, and that colors identified with memory tend to distribute within their own color-category regions or their neighbor color-category regions, depending on their positions in a color space. These findings indicate that color memory is characterized by the color categories, suggesting a color-category mechanism in a higher level of color vision. © 1996 John Wiley & Sons, Inc. 相似文献
18.
Ralph W. Pridmore 《Color research and application》2011,36(6):394-412
I describe complementary colors' physiology and functional roles in color vision, in a three‐stage theory (receptor, opponent color, and complementary color stages). 40 specific roles include the complementary structuring of: S and L cones, opponent single cells, cardinal directions, hue cycle structure, hue constancy, trichromatic color mixture, additive/subtractive primaries, two unique hues, color mixture space, uniform hue difference, lightness‐, saturation‐, and wavelength/hue‐discrimination, spectral sensitivity, chromatic adaptation, metamerism, chromatic induction, Helson‐Judd effect, colored shadows, color rendering, warm‐cool colors, brilliance, color harmony, Aristotle's flight of colors, white‐black responsivity, Helmholtz‐Kohlrausch effect, rainbows/halos/glories, dichromatism, spectral‐sharpening, and trimodality of functions (RGB peaks, CMY troughs whose complementarism adapts functions to illuminant). The 40 specific roles fall into 3 general roles: color mixture, color constancy, and color perception. Complementarism evidently structures much of the visual process. Its physiology is evident in complementarism of cones, and opponent single cells in retina, LGN, and cortex. Genetics show our first cones were S and L, which are complementary in daylight D65, giving a standard white to aid chromatic adaptation. M cone later split from L to oppose the nonspectral (red and purple) hues mixed from S+L. Response curves and wavelength peaks of cones L, S, and (S+L), M, closely resemble, and lead to, those of opponent‐color chromatic responses y, b, and r, g, a bimodal system whose summation gives spectral‐sharpened trimodal complementarism (RGB peaks, CMY troughs). Spectral sharpening demands a post‐receptoral, post‐opponent‐colors location, hence a third stage. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2011 相似文献
19.
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
20.
Rolf G. Kuehni 《Color research and application》2007,32(2):92-99
The development of the idea of simple or fundamental colors in Western culture from classical Greece to the early 17th century is shown, with particular emphasis on writers in the 16th and early 17th centuries. Four streams of thought are found: (1) Aristotle's seven colors, congruent with seven tastes and seven tones, thus symptomatic of an underlying general harmony; (2) Four‐basic‐color sequences where colors are emblematic of the four classical elements; (3) Spectral sequences; (4) Three simple chromatic colors between white and black, based on colorant mixture. In the late 16th century seven‐color sequences came to represent categorical sequences, in addition to shorter fundamental color sequences. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 92 – 99, 2007 相似文献