Abstract: The position and the color of a light source affect the image ofan object,and ideal results can't be obtained by usual segmentation algorithmdue to the appearence of highlights.The Dichromatic Reflection Model is usedto divide a color image into two intrinsic images——matte image and highl-ight image.The matte image is the original image with the highlights remo-ved,reflecting the invariance of the object and being not affected by theenvironmental factors(such as the position and the color of the light sour-ce);but the highlight image is just an image of highlights,reflecting theenvironmental factors,and providing information for shape from gloss.The color image in this paper refers to that of a monochrome object gene-rated by color CCD camera under monochrome light(not the light with singlewavelength).