A Color Image Database for Realistic Image Rendition

摘要

A color image database of different scenes under several fixed illuminants is constructed in this paper. It contains images for 45 scenes captured under illumination of various color, lightness. Some analysis based on the database are described to find the relationship between chromatic/lightness distribution of images under different illumination. Indexes as overall mean and SD are introduced, which are reasonable to evaluate image lightness and contrast coordinating to visually representation. In order to objectively assess the influence of illuminant color to images, investigation on lαβ and r-g chromatic map are explored. An improved hue correlation method is proposed based on α,β mean/SD statistical analysis, which shows excellent color constancy performance on CPVO measurement. The CPVO measurement is also established on r-g chromatic peak offset tests in this paper.