An image forming apparatus includes: an acquiring unit; a resolution converting unit; a receiving unit; a position determining unit; a correcting unit; and a scaling unit. The acquiring unit acquires image data composed of a plurality of pixels; the scaling-factor determining unit determines a scaling factor of the acquired image data; the resolution converting unit converts a resolution of the acquired image data into a higher resolution than the resolution of the image data; the receiving unit receives a designation of a sub-scanning directional shift amount of a correction pixel to be corrected; a position determining unit performs a position determining process; and the scaling unit scales the image data at the determined scaling factor by causing the position determining unit and the correcting unit.