The present invention provides an image processor for outputting image data to an image forming device forming an image with use of a recording material having a plurality of color components. The processor comprises a component determining a region having higher brightness than predetermined brightness and a region having lower brightness than the predetermined brightness in the image data based on the image data and a component adjusting saturation so as to reduce density values of color components other than a color component having a maximum density value among the plurality of color components of the recording material to increase saturation in a region having brightness determined to be high and reduce density values of color components other than a color component having a minimum density value among the plurality of color components of the recording material to decrease saturation in a region having brightness determined to be low.