METHOD AND APPARATUS FOR IMAGE PROCESSING, INCLUDING PROCESSING FOR REPRODUCING BLACK CHARACTER AREAS OF COLOR AND MONOCHROMATIC IMAGES

In an image processor which converts color image data to image data of cyan, magenta, yellow and black necessary for forming an image, a black character edge is discriminated in R, G, B image data. The edge component in a black character area is deleted by narrowing on image data of cyan, magenta and yellow. Further, in a black character area, K data is replaced with maximum density data in the R, G, B data, and edge emphasis is performed on the substituted data. Then, reproducibility of a thin line portion in a character is improved largely.