Graying for images with color-discrete characteristic

It is realized that there is a category of images with color-discrete characteristic, widely investigated in the fields of machine vision, image processing and pattern recognition. Despite the authority of weighted-average method on graying, it is not robust enough in the preceding case. In this paper, a graying method based on trichromatic imaging and color-discrete characteristic is proposed. Detailed experimental evidence has demonstrated that this method can maximize contrast of target region furthest while graying; also this feature can improve performance of thresholding and image enhancement, which has significant effect on image processing tasks in natural scenes. In addition, the proposed may help to optimize design of imaging devices.