1. An image processing apparatus for generating a print image based on print data including a plurality of layers, the image processing apparatus comprising: a determining unit that determines whether objects included in different layers overlap each other in a single pixel constituting said print image; and a selecting unit that selects image processing to be performed with respect to said single pixel according to a combination of attribute information for each of said layers assigned to said single pixel, when said determining unit determines that the objects overlap each other.