An image forming apparatus acquires an input image generated by reading an image of an original document to be copied, and determination information of whether or not the input image corresponds to a blank. The image forming apparatus controls a printer to print the input image together with a page number on a sheet and output the sheet, according to a determination result indicated by the determination information. At that time, the image forming apparatus controls the printer so as to output a sheet on which the page number is not printed, with respect to the input image determined to correspond to a blank.