Distribution of Color Names in Color Appearance Space

点击翻译按钮获取中文摘要

The CIE color rendering index is not based on the color appearance of the object but on the color differences between the objects under different illuminants. When we need to identify color of the object, however, it becomes important to know how color appearances of the object change according to the change of illuminant. In this study, 292 Munsell Color Samples under 11 illuminants. The illuminance was 1000 lux for all illuminants. Subjects were asked to sort samples into eleven basic color categories specified by Berlin and. Sorting of each color samples under each illuminant was repeated three times in different experimental sessions. The lightness J, the chroma C and the hue angle h defined by the CIECAM97s were calculated for all color samples sorted consistently in a same color name under each illuminant. The basic color name regions were plotted in the CIECAM97s space. Let the area of each color name regions Si. The subscription i corresponds to each color name. Eighty color chips which belong in elsewhere of eleven basic categories under the D65 illuminant are selected as reference color samples. At first, color chips belong in the same color category under the D65 illuminant were classified. Then the area St in the CIECAM97s space of these classified samples under the test light source are calculated. The overlap area between Si and St, (Sr∩St) are determined. The index of categorical color rendering proposed here was defined as 100 (Si∩St)/St. The order from best to worst rated by the index of categorical color rendering was not completely agreed with the general color-rendering index (Ra) specified by the CIE.