An image processing apparatus that generates a pattern of a colorless recording material to form an image using the colorless recording material includes: a region dividing unit that divides an input image into a plurality of regions as divided regions using a designated algorithm and pixel values of pixels that form the image; a spatial-frequency calculating unit that calculates spatial frequencies in each of the divided regions into which the image has been divided using pixel values in the divided region; and a pattern generating unit that generates a pattern of the colorless recording material, which is set to each of the divided regions, using the calculated spatial frequencies and a line pattern having a preset line width.