A determining unit extracts similar-characteristic areas in image data and determines a type of the characteristics of image data of each of the similar-characteristic areas, a first correcting unit corrects a characteristic of image data in each of the similar-characteristic areas to a predetermined data characteristic according to the type of the characteristics of image data of that similar-characteristic area thereby obtaining characteristics-corrected image data, a storage unit stores therein the image data and the characteristics-corrected image data, a second correcting unit corrects a characteristic of the image data and the characteristics-corrected image data stored in the storage unit to a destination-specific characteristic that corresponds to a destination to which image data is to be output, and an output unit outputs the image data having the destination-specific characteristic to the destination.