An image forming apparatus executes banding correction at a level determined according to variation of the density characteristic of the image forming apparatus to achieve a high quality image. In the image forming apparatus, a banding correction unit acquires information about a cause of density variation that may occur in a sub scanning direction of a rotation member, which is used for forming a toner image on an image carrier based on input image information and sets, based on the acquired information, the level of the density correction, which is determined according to the density variation cause information.