基于CIE LAB色差公式的翡翠绿色明度差对色差的贡献

通过翡翠绿色的色差计算,分析明度差DL、彩度差DC、色调差DH对综合色差DE的贡献.采用CIE L*a*b*均匀色空间中CIE LAB色差公式的计算结果显示,肉眼下66粒质地细腻、绿色均匀的优质翡翠戒面的明度值L*∈(38.50,61.80),属中等偏低的明亮程度;彩度范围C*∈(11.49,44.99),也属中等偏低;色调范围h0∈(134.32,152.96),属略带黄色调的鲜艳绿色.翡翠绿色的平均色差DELAB-AVE=6.10达肉眼可识别级别,平均饱和度差-0.22与平均色调角差0.06均很低,对总色差贡献不大,而明度差DL则表现出了与总色差很高的一致性.得出结论,对中低明度的翡翠绿色色差的最直接贡献者为其明度差,依此建议采用首先以彩度和色调的二元体系作为翡翠绿色定量分级体系,进而依据三维均匀色空间模型CIE L*a*b*,构建以色差为基本单位,明度为Z轴、彩度为X轴和色调为Y轴的三元质量分级体系.     

电子书阅读器文字显示质量评价方法研究

建立了用于电子书阅读器文字显示质量的评价方法。基于电子书材料的光谱反射率特征,结合常用阅读用照明光源光谱和人眼的光谱视见特性,定义了该类器件白场与暗场的亮度对比度CL和白场亮度YW性能参数。通过对12个产品的参数测量和主观评价实验,定义并分析了文字显示清晰度感知质量评价指数QC与CL和YW的相关性。结果表明:QC与CL和YW均有关;在线性相关的情况下即可较好地预测文字显示的清晰度感知质量。此外,采用CIELAB彩度Ca*b参数量化了电子书背景白的偏色程度,并通过主观评价实验表明,Ca*b彩度值增大会降低文字阅读的舒适度;大于6的Ca*b彩度值将使阅读产生不舒适感觉。     

高性能与可持续性的完美结合 朗盛推出面向涂饰的新型水性染料

<正>德国朗盛集团最近推出皮革涂饰产品系列新型水性染料——Levaderm WB系列。该系列产品包含黄色、橙色、红色、枣红色、蓝色、深蓝色、绿色、浅棕色、中棕色、深棕色、灰色和黑色,适用于喷涂、通过式染色、效应层、底层和顶光。朗盛皮革业务部(LEA)有机皮革化学品业务线负责人Thomas Brackemeyer博士表示:"Levaderm WB系列产品的特点是染色率高、亮度纯、匀染力超强、牢度性能卓     

玻璃渗透氧化铝全瓷牙科修复材料的颜色性能

以CeO2, Fe2O3, Er2O3为着色剂,制备不同颜色的Al2O3渗透玻璃,并渗透入预烧结的多孔Al2O3坯体,用分光光度计测量渗透后Al2O3-玻璃复合材料的反射光谱和颜色参数,考察了着色剂含量对材料颜色的影响. 结果表明,CeO2能赋予材料黄色品,对降低明度和增加红色品作用较弱;Fe2O3能赋予材料红色品并显著降低明度;Er2O3能增加红色品,对明度和黄色品影响较小. 得到的色度范围为L*(明度)73.5~91.6, a*(红绿色品)-2.84~4.11, b*(黄蓝色品) 15.6~25.3. 对实验数据拟合得到配色模型,以市售核瓷产品为目标进行配色,色差均小于1.5,满足颜色匹配的要求.     

CIE1976 L*a*b*均匀色空间下照度对锰铝榴石颜色的评价

通过照度实验,基于CIE1976L*a*b*均匀色空间研究照度对锰铝榴石颜色评价的影响.照度增加,锰铝榴石黄色的明度L*显著增加,且自身明度较低的锰铝榴石黄色明度更易受照度变化的影响.△a*平均为17.30,△b*平均为36.83,明显大于△a*的均值,表明照度对锰铝榴石黄色调的影响更大;当照度较低时,彩度C*与照度呈正相关,当照度超过227.73 lx后,C*将不再增大或与照度呈负相关;色调角h0随照度增加而增大,平均色调角增量△h0=11.59,增幅较明度和彩度小.同时验证Stevens效应、Hunt效应、Helmholtz-Kohlrausch效应、Bezold-Brücke色相偏移理论在锰铝榴石颜色观察上的体现.此外,当明度差值DL* ＞15时,DL*与色差DE2000呈正相关且相关性最大,说明明度对色差具有最大贡献.得出结论,照度影响锰铝榴石的明度、彩度、色相,间接影响色差,其中对明度影响最直观,故在质量评价时应严格控制照度标准.     

朗盛推出面向涂饰的新型水性染料

<正>2017年8月16日,朗盛推出皮革涂饰产品系列新型水性染料——Levaderm WB系列。该系列产品包含黄色、橙色、红色、枣红色、蓝色、深蓝色、绿色、浅棕色、中棕色、深棕色、灰色和黑色,适用于喷涂、通过式染色、效应层、底层和顶光。朗盛皮革业务部(LEA)有机皮革化学品业务线负责人Thomas Brackemeyer博士表示:"Levaderm WB     

Zeus已开始商业化生产聚醚醚酮并纺纤维

美国南卡罗来纳州奥兰治堡消息，Zeus，Inc．宣布已开始商业化生产PEEK Drawn Fiber（聚醚醚酮并纺纤维）。Zeus目前可以挤出的纤维尺寸范围从0．003-0．040英寸。为了满足特种行业对于编织物的需求，Zeus公司可以提供天然、黑色、红色、绿色、黄色、蓝色、桔红和紫色产品。     

喷墨打印用着色剂技术进展（一）

目前使用和研究的喷墨打印用着色剂以水性染料为主,基本色是黑色、品红色、黄色和青色。水溶性黑色染料以多偶氮结构为主,要求具有好的耐水性和抗玷污牢度,近年的研究集中在非诱变性和非致癌性的黑色染料开发上;品红色染料的化学结构有氧杂蒽型和偶氮型等,目前还未找到一只色彩、光牢度、耐水性均理想的水性品红色染料;大多数水溶性黄色染料特别是黄色直接染料都可用于喷墨打印,耐光性与耐水性好;酮酞菁类磺化行生物是喷墨打印中使用最多的青色染料,其亮度高,耐光性、耐水性、稳定性好。     

新型紫外荧光油墨的研制

以自制的有机荧光粉为原料，研制了４种荧光油墨，在日光下，其印迹为白色，但在紫外线下分别呈鲜明的红色、黄色、绿色及蓝色荧光。测试了其荧光性质及质量标准。     

影墨游戏

<正>Claire Gillo为你演示如何用一罐黑色颜料来创造出大师级的抽象作品抽象艺术和摄影有着非常密切的关系。摄影发明伊始,画家和摄影师就尝试将这两种媒介结合以创造出更好的艺术作品。即使你没有受过什么绘画的训练也不要担心:我们接下来介绍的拍摄方法并不需要任何绘画技巧,只要你的一点创意和想象力就足够了。你需要有一罐黑色颜料(我们是在附近的商店里买到的)和一支白色笔刷。另外还有一个三脚架、闪光灯和一桶水。如果你喜欢更加缤纷的效果,那便不必只用黑色颜料。但还是要考虑哪些颜料混合起来比较好看:例如黄色和蓝色混合可以得到绿色,黄色和红色混合可以得到橙色。     

Hue,chroma, and lightness preference in Chinese adults: Age and gender differences

Recent studies have shown cultural differences in color preference. However, the color preference of people in China, which was found to have its own pattern, was yet to be studied in depth. The current study investigated color preference and the associated age and gender differences in an adult national sample (N = 1290) to provide a culture‐specific characteristic of color perception. Participants rated how much they liked each of 31 colors (four chroma‐lightness levels of red, orange, yellow, green, cyan, blue, and purple, plus three achromatic colors). We found a unique saturated color preference pattern characterized by red, cyan, and blue being preferred the most and orange as the least preferred chromatic color. The “red preference” phenomenon was observed in Chinese adults. Light colors were preferred the most in terms of chroma‐lightness level, followed by saturated, muted, and dark colors. The results of a principal component analysis of the 28 chromatic colors showed that blue‐green‐like colors (cool colors) constituted the largest proportion of color preference. The preference for orange and several dark colors increased with age, while that for bluish colors, purple, yellow, white, black, and light colors decreased. In terms of gender, women liked cyan, white, pink, and light colors and disliked red, orange, and dark colors more than men did. Our findings provide new empirical evidence about the color preference of Chinese and may offer some insight into the study of color preference and lay the foundations for future theoretical and practical research.     

Three are Not Enough: An INDSCAL Analysis Suggesting that Color Space Has Seven (£1) Dimensions

Forty-five subjects, including color normals, protanomalous, deuteranomalous, protanopes, and deuteranopes, judged dissimilarities of 26 Munsell color chips chosen to span the full color space (i.e., all three parameters—hue, saturation, and lightness—were varied). Each of the 325 pairs of colors was mounted on a standard grey background board. They were presented to subjects in different random orders and were viewed under a Macbeth daylight lamp. For each pair the subject circled a number varying from 0 (for “identical”) to 9 (for “maximally dissimilar”). Fifty data matrices obtained from 45 subjects (5 were from the same subject on different dates and 2 were from another subject) were analyzed by the INDSCAL method. The three-dimensional solution yielded the “standard” three dimensions (lightness, red-green, and yellow-blue) with the classical “color circle” emerging, in a slightly distorted form, in the plane of the second and third dimensions. Seven dimensions seemed necessary to account fully for these data, however. In seven dimensions each of the “standard” dimensions is paired with a “folded” version. Accompanying lightness is a “folded” lightness dimensions, which we have called “lightness contrast.” The light and dark colors are at one end, contrasted with medium colors at the other. Similarly, “folded” red-green roughly contrasts red and green with blue, yellow, and the greys, while “folded” yellow-blue contrasts blue and yellow with red, green, and the greys. The seventh dimension, which may be artifactual, was called “split yellow.” It contrasts very brilliant (high Munsell value and chroma) yellow and orange colors with all the other colors. It is speculated that some of these extra dimensions may relate to anomalous receptor processes characteristic of deviant subjects. The INDSCAL subject space enables discrimination among all five subject types. Specifically, one of the “natural planes” (the red-green versus “folded” yellow-blue plane) of the seven-dimensional solution can be divided into contiguous and fairly compact regions, with each subject type occupying a unique region.     

Hue cycle described by graphs and color names

The color appearance of the hue cycle in equal radiance is described in hue, saturation, and brightness/lightness. The latter does not resemble CIE luminance Y (peaking at 555 nm green), but peaks near 570 nm yellow with minor peaks near 490 nm cyan and 530 c magenta. Saturation per watt peaks near 450, 530, 610 nm (blue, green, red). Newton's choice of seven spectrum colors, and particularly his two bluish colors, is explained as major colors rather than merely different hues.     

Preprocessing to CIECAM02 input color with chromatic background

A preprocessing to CIECAM02 input color for color appearance prediction was proposed. In this study, 8640 color appearance matching pairs (NCS color charts with red, green, yellow, and blue backgrounds in a light booth and their reproductions with gray background on a CRT screen) were obtained by psychophysical experiment using the simultaneous‐binocular technique. Because only the lightness of background is included in CIECAM02, a color inducing vector based on opponent‐colors theory was introduced to preprocess CIECAM02 inputs, so that CIECAM02 may predict the corresponding color of an input color with chromatic background as well. By data fitting, a color preprocessing formula describing a relationship between the color inducing vector and the NCS chromaticness was conducted. Furthermore, the formula's performance was tested and the results showed that it was good for implementing the color appearance prediction of input colors with different chromatic backgrounds.© 2006 Wiley Periodicals, Inc. Col Res Appl, 32, 40–46, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20287     

Classification of colors through fuzzy statistical experiment

The membership function describing the degree of association of a color sample to a specified color name is estimated experimentally through fuzzy statistical experiment. Here, we are interested in the surface color of opaque materials including red, orange, yellow, green, blue, purple, white, gray, and black. The characteristics of the membership function for these colors are found to be affected appreciably by the light source used.     

Color identification data obtained from photopic to mesopic illuminance levels

To use colors properly as an aid in visual tasks, it is necessary to know how colors are identified under various illuminating environments. In this study color identification was examined under a wide range of illuminances, from photopic to mesopic levels. Fifteen subjects named a color chip using one of the preselected color terms: red, orange, yellow, yellow‐green, green, blue‐green, blue, purple, pink, brown, white, gray, and black. The 256 color chips were selected from value planes of 4, 6, and 8 of the Munsell color space. The illuminance levels tested were 1000, 10, 1, and 0.1 lx. At 1000 lx the color chips were identified consistently by each of the color terms. At 10 lx the pattern of color identification was very similar to that at 1000 lx, though the consistency of the identification evidently declined. At 1 lx great changes in color identification occurred. By 0.1 lx reliable color identification was completely lost, though blue and red responses remained. At the lower illuminances green was replaced with blue, and red, orange, and pink were frequently confused with each other. However, the border between blue and purple was almost constant. These results provide a scientific basis for the appropriate use of colors in various illuminating environments. Also, they are useful for studies in color appearance modeling. © 2002 Wiley Periodicals, Inc. Col Res Appl, 27, 252–259, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10065     

Effect of texture on color variation in inkjet‐printed woven textiles

Inkjet‐printed textiles are influenced by a wide range of parameters due to highly diverse textile structures and the resulting textures. The goal of this study is to understand the effect of texture on color appearance in inkjet‐printed woven textiles. Cotton‐woven samples were constructed with nine different weave structures. Each sample was digitally printed with identical squares of primary colors cyan, magenta, and yellow and secondary colors red, green, and blue. The amount of ink applied was controlled consistently with an image editing software. CIE L* values were calculated from the measured reflectance. 25 observers ranked the perceived texture and color lightness of each sample. Perceived visual texture and perceived color lightness scales were estimated from the rankings using the rank order method. The measured CIE L* values and the scale of perceived lightness were positively related for the primary and secondary colors. Instrumental measurements of the textile surface characteristics were positively related to the visual scale. Texture was demonstrated to cause a measurable effect on color results in inkjet printing, both using instrumental and perceptual measures. To investigate if the color differences were substantial enough to cause “out of tolerance” ratings in textiles based on common textile industry color acceptance procedures, color differences among the samples were calculated and compared to a reference sample. Results demonstrated that color variation due to texture was sufficient to lead to rejection of a printed color in comparison to a color specification. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 297–303, 2015     

Gray and grayness—its complexities in color appearance of surface colors

Complexities on the roles of reference color gray and grayness are reviewed. They are essential in color appearance, but gray is an implicit color. Although “grayness” is not explicitly used in visual color assessment of surface colors or color order systems, gray can be combined with any colors having six primary‐color components using the term “grayish,” for example, grayish red and grayish yellow. However, the existing region of grayness is limited in a part of color‐appearance space. Illuminance dependency of gray perception is also clarified. Existence of two kinds of psychometric quantities are suggested: one is the attribute of grayness based on its psychological amount in a grayish color under study, and the other is the attribute of brightness of the grayish color under a specified illuminance, psychophysical quantity. The Nayatani‐Theoretical color order system, which uses three opponent‐colors axes, can clarify the above complexities of gray and grayness. Its importance is the same as six primary colors, red–green, yellow–blue, and white–black. © 2012 Wiley Periodicals, Inc. Col Res Appl, 39, 37–44, 2014     

Investigating the personality associations evoked by single colors: An exploratory study

Despite the crucial role of color appearance in forming first impressions, it is still not clear how color evokes personality associations—that is, a color‐personality association (CPA). This study aims to propose a method for quantifying the relationships between color attributes and CPAs for single colors. Specifically, we first collected the CPAs of five traits evoked by single colors (i.e., extraverted–introverted, moody–unemotional, agreeable–disagreeable, organized–disorganized, and wide interests–narrow interests) in a carefully controlled experiment. Then, multiple linear regression (MLR) analyses were adopted to predict these CPAs based on three color attributes (lightness, chroma, and hue). Our results showed that (1) the personality associations could be evoked by colors and perceived consistently by observers; (2) the relationships between the color attributes and the CPAs could be well quantified by separately conducting MLR analyses in different regions of hue (i.e., red, green, blue, and yellow regions); and (3) both lightness and chroma were significant predictors in almost all predictive models and they might have different relative importance or directions of effect when predicting the CPAs in different regions of hue, even for the same trait. This study improves the understanding of how color evokes personality associations and takes the first step toward developing the method for predicting the CPAs for multicolor combinations. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 388–396, 2017     

Perceptual and emotional effects of light and color in a simulated retail space

This article aims to address two aspects of lighting often treated intuitively by designers in charge of creating retail atmospheres, that is, the impact of color and light distribution, as design variables. The study comprised a controlled experiment with a repeated measure design with three directions of lighting (front, overhead, and wallwasher), as the within‐subject factor and four color combinations of the walls (yellow‐blue, magenta, gray, and green‐magenta), as the between‐group variable. The perceptual (visually) and emotional responses of 184 participants revealed the interplay between light and color on these psychological outcomes. Specifically, the results showed that the overhead direction of lighting improves the appearance of the less favored color conditions, either in terms of lack of visual complexity (monochromatic) or color itself (gray). In turn, the wallwasher lighting emphasized these attributes, differing according to visual or emotional aspects. In retailing, emotional dimensions such as activation and evaluation are desired, and they were confirmed across all the lighting and color conditions of this study. The results provide designers with certain perceptual cues regarding colors and their lighting mode to create desirable impressions and affect in retail spaces.