Image forming apparatus and image forming method capable of revising gray image

摘要

An apparatus includes a gray converter to convert an inputted color image to be printed into a gray conversion image and to outputs the gray conversion image a difference calculator to calculate a at least one difference value between at least one color channel image with respect to the color image and the gray conversion image; and a gray reviser to revise the gray conversion image based on the at least one difference value and to output a gray conversion image.