SUBTRACTIVE COLOR METHOD, SUBTRACTIVE COLOR PROCESSING APPARATUS, IMAGE FORMING APPARATUS, AND COMPUTER-READABLE STORAGE MEDIUM FOR COMPUTER PROGRAM

摘要

A most used color that is a most popularly used color is obtained in an image. Pixel groups formed of continued pixels having an identical color other than the most used color in the image is extracted as first pixel groups. Pixel groups having a color of which a color difference with respect to the most used color is smaller than a predetermined threshold and having a size thereof that is smaller than a predetermined size is extracted as third pixel groups among the first pixel groups thus extracted. The first pixel groups other than the third pixel groups are taken as second pixel groups. An image is generated by replacing colors of portions, which correspond to the second pixel groups in an image having an area identical with that of an image to be processed and filled with the most used color, with the corresponding second pixel groups, respectively.