A method for processing an image includes: determining a reduction ratio that falls within a predetermined range; generating reduced image data indicative of a reduced image based on original image data indicative of an original image by dimensionally reducing the size of the original image to the size of the reduced image by the determined reduction ratio, the reduced image data indicating density values of pixels contained in the reduced image; and emphasizing edges in the reduced image by amplifying a change in the density values of pixels belonging to the edges in the reduced image based on the density values of the pixels contained in the reduced image. The emphasizing edges includes: correcting the density values of the pixels in the reduced image data by using correction data; and modifying the correction data to be used for correction of the density values of the pixels in the reduced image data, the correction data being modified dependently on the reduction ratio, to thereby vary a level of amplification of the change in the density values dependently on the reduction ratio.