An apparatus for creating an ICC profile in a simple manner without using a specialized measuring instrument. A display control unit reads out a dot pattern image from a pattern image data holding unit and a grayscale pattern image containing a plurality of grayscale patches of gradually varying gray scale from a grayscale image data holding unit, and presents the thus readout images for display on a display device. A user selects the grayscale patch having brightness closest to the brightness of the dot pattern image by operating a selection unit. Based on the selection, a gamma coefficient value is calculated by a gamma coefficient value calculation unit, and based on this gamma coefficient value, a profile creation unit modifies the ICC profile held in a common information holding unit and thus creates a customized ICC profile.