Method for detecting the illumination color of a color image from an average of chromaticity coordinates generated from linear approximations of color transition bands

摘要

A method for detecting the illumination color to store the color-compensated image considering the light effect of illumination environments on photographing with a color image input apparatus such as a video camera. The present invention provides a method for finding highlight areas appearing on the objects in the image and obtaining the illumination color resulting from the analysis of the color of the pixels included in those highlight areas. The chromaticity coordinates of the pixels in a highlight area occurring on the uniformly colored object are distributed between the body color of the object and the illumination color. The distribution of those chromaticity coordinates is referred to as the color transition band. The straight lines are approximated on the chromaticity diagram using these color transition bands obtained from highlight areas presenting several uniformly colored objects. The illumination color is determined as the average of the intersections between the lines. In this way, the present invention may reduce the excessive processing time found in the prior art method, providing more reliable information about the illumination color.