An image processing apparatus includes an address specifying unit, a reading unit, a writing unit, and a shifting unit. The address specifying unit specifies an address in a storage device that stores therein pixel data of an image. The reading unit reads the pixel data from the address by a line pixel amount. The writing unit writes the pixel data in an output storage unit. The shifting unit shifts the address in either one of a first direction along a sub-scanning direction and a second direction opposite to the first direction by a predetermined amount.