There is provided an image processing apparatus that generates print data for printing by an inkjet printing apparatus, based on a rendering command group that includes a rendering command for a vector image, comprising: a determination unit which determines, for each rendering command included in the rendering command group, whether ink having a predetermined property is to be used; a rendering unit which renders in a first memory a raster image corresponding to a rendering command for ink having the predetermined property is to be used, and renders in a second memory a raster image corresponding to a rendering command for ink having the predetermined property is not to be used; a lossy compression unit which lossily compresses the raster image in the first memory; and a generation unit which generates print data that includes the raster image in the first memory and the raster image in the second memory.