An image processing device includes; an image segmentation unit that divides an image information set into a plurality of image areas, the image information set forming a plurality of lines each constituted of colored pixels arrayed in a first direction, and the image information set expressing gradations forming an image as a number of the colored pixels existing in a predetermined image area; an image area shift unit that shifts the predetermined image area among the plurality of image areas in a second direction different from the first direction, relative to an image area substantially contiguous to the predetermined image area; and a pixel replacement unit that replaces the colored pixels forming part of each of the lines and existing within a predetermined distance range from the boundary, with at least one of the colored pixels intervening between the lines.