An image forming apparatus includes a gradation correction unit configured to perform a correction process on first image data expressing first gradation values, and output second image data expressing second gradation values. The gradation correction unit is configured to determine the second gradation values based on the first gradation values of a plurality of colors of a plurality of pixels in an area including a process target pixel and having a size corresponding to a first color misregistration amount. The gradation correction unit is further configured to determine the second gradation values such that there is no pixel in which a sum of the second gradation values of the plurality of colors exceeds a first threshold value, even when color misregistration within the first color misregistration amount occurs.