Discussing the defination of color image contrast

Based on the predecessors,research on contrast,we further modify,analyze and discuss in order to put forward an idea that color image can be decomposed into luminant and chromatic image,find out the relation of luminant image contrast,chromatic image contrast and color image contrast,put forward a color contrast formula,analyze and discuss its practicability.So we hope it can be applied in the practical research of spin,printing and dyeing,pigment etc.