Wide-band multi-spectral space for color representation

This paper develops a wide-band multi-spectral space for color representation with Aitken PCA algorithm. This novel mathematical space using the broad-band spectra matching method aims at improving the accuracy of color representation as well as reducing costs for processing and storing multi-spectral images. The results show that the space can present our experimental original spectral spaces (i. e. Munsell color matt and DIN-6164 color chips) with high efficiency, and that the spanning space with three eigenvectors can present the original space at more than 98% CSCR, and when 5 eigenvectors are used it can cover almost the whole original spaces.     

白昼光与验色仪

提出我国自行设计,用特制电源控制的高压短弧氙灯和光谱调节器计算、研制成功的验色仪。并叙述了设计验色仪的指导思想,理论计算与实验装置。指出验色仪中的白昼光模拟器（Ｄ６５光源）六项技术指标均达到ＣＩＥ（ＩｎｔｅｍａｔｉｏｎａｌＣｏｍｍｉｓｓｉｏｎｏｎＩｌｌｕｍｉｎａｔｉｏｎ）和先进国家规定的标准．     

色彩表示的宽带多光谱空间研究

在主成分分析法的基础上建立了色彩表示的宽带多光谱空间，并定义了累积空间覆盖率(CSCR)来表征特定空闻下光谱的重建效率。实验结果表明，该空间能以很高的精度来表示原始光谱空间。     

Wide—Band Multi—spectral Space for Color Representation

This paper develops a wide-band multi-spectral space for color representation with Aitken PCA al-gorithm. This novel mathematical space using the broad-band spectra matching metod aims at improving the accuracy of color representation as well as reducing costs for processing and storing multi-spectral images.The results show that the space can present our experimental original spectral spaces(i,e.Munsell color matt and DIN-6164 color chips)with high efficiency,and that the spanning space with three eigenvectors can present the original space at more than 98% CSCR,and when 5eigenvectors are used it can cover almost the whole original spaces.     

Metamerism Appreciation of Jadeite-Jade Green under the Standard Light Sources D65, A and CWF

We tested 288 pieces of the polished cabochon jadeite-jade with high quality green and smooth surfaces using the colorimeter Color i5 based on the CIE 1976 L~*a~*b~* uniform color space. The color changes after alternating three CIE standard light sources D_(65),A and CWF were compared,and the degree of metamerism was evaluated. The results show that the CIE standard light sources D_(65),A and CWF increase the chroma of green and turn bluish green into vivid green,which are similar or to nearly colorless and transparent glass-like samples with fine textures. When the three light sources were individually alternated,the lightness of the jadeite-jades showed little change,but the tone changed significantly. Metamerism occurred only in 3 pairs among the 16 samples that were selected by cluster analysis for quality,and the metamerism colors were highly consistent of L~*D_(65)∈(43.47,46.75),C~*D_(65)∈(65.20,68.80) and ho~*D_(65)∈(138.10,140.23). We can conclude that the jadeite-jade green gradually turns to blue when the color temperature of the light source increases. But when considering both the light sources and the samples,D_(65) is more suitable to be the light source of jadeite-jade green when compared with the light sources CWF and A. Compared with the CIE standard green and high chroma green,high-quality jadeite-jade green has a slight yellow tone,low lightness and high chroma. The special metamerism index decreased to 1 when the light source alternated among D_(65),A and CWF. Therefore,the color of jadeite-jade green might be slightly influenced by alternating of the light sources.     

绿色翡翠同色异谱的色度学特征及评价

翡翠颜色随外界环境的不同而有所变化，通过引入同色异谱概念，对绿色翡翠的颜色进行定量计算。实验表明：更换照明光源后求得的不同样品间的同色异谱指数Mt有很大差别，而同一样品颜色的主波长值也会相应变化，颜色变化程度低的易成为优质翡翠。提出，可将同色异谱作为衡量翡翠优劣的一个定性指标，用以指导绿色翡翠的鉴定、评价，指出同色异谱方法更适用于优质翡翠的评估。