Patent ID: 8098413

Claim:
An image output apparatus that supplies output image data including color components of color materials to an image forming apparatus that prints an image represented by input image data using at least one chromatic color material and an achromatic color material, the image output apparatus comprising: a color separation unit configured to convert the input image data into the image data including the color components of a plurality of color materials used in the image forming apparatus; and a gradation correction unit configured to correct gradation levels of the image data which includes the color components of the plurality of color materials and which has been converted by the color separation unit using a gradation correction table, wherein, the gradation correction unit uses the gradation correction table for a chromatic color material among the plurality of color materials such that an amount of brightness value change of the image data after the gradation correction processing to the image data converted by the color conversion unit is nonlinearly represented relative to an amount of signal value change of the image data after the color conversion processing, and that the amount of brightness value change of the image data after the gradation correction processing increases as the amount of signal value change of the image data after the color conversion processing increases.