1. An image processing apparatus for performing image processing for a plurality of band areas obtained by dividing image data, the image processing apparatus comprising: a dividing unit configured to divide the image data such that each of the plurality of band areas has an area overlapping an adjacent band area; and an image processing unit configured to perform the image processing for the band areas with respect to each of a plurality of planes that constitute the image data, wherein a processing range within a band area used in the image processing by the image processing unit differs between at least two planes among the plurality of planes.