The aim of this investigation was to point out that color-appearance estimation and color vividness estimation are of critical importance in subjective judgment of image quality. We also show that image quality depends, either on the color appearance of each image elements, or on the color appearance of background elements, according to subjective criteria used by observers to make their judgment. In order to study: the quality of a color image, we propose to use different image descriptors based on the analysis of the color distribution of image elements, and of the spatial distribution of color image elements. We also study the degree of correlation between these qualitative descriptors and subjective judgments. This study has confirmed that although colorfulness attributes and color appearance attributes are essential, they are nor sufficient to indicate naturalness of images when chroma varies from one image to an another one. Likewise this study has demonstrated that local analysis plays an important role in subjective judgment, especially in perceptual judgment of color appearance. (C) 2000 John Wiley & Sons, Inc.