Image processing apparatus with improved compression of image data of character images and background images using respective different compressing methods

摘要

An edge image generating unit detects edges in an original image and generates an edge image from the edges. A connection pixel extracting unit extracts connection pixel sets in the edge image. A binary image generating unit classifies colors of the connection pixel sets into a predetermined number of achromatic target colors and a predetermined number of chromatic target colors if a color mode is set as color, and classifies the colors of the connection pixel sets into a predetermined number of achromatic target colors if the color mode is set as monochrome, where the number of the achromatic target colors set in the color mode of monochrome is larger than the number of the achromatic target colors in the color mode of color.