In this invention, to enable printing of an image that has undergone an image process or print process complying with the desire of a user on an image supply device side, real object handles and virtual object handles are set to, of images to be supplied to the printing device, images that require a predetermined image process and remaining images, respectively. A print job including the object handle of a print target image is issued in accordance with a print instruction. If the handle of an image requested by the printing device in response to the issued print job is a virtual object handle, the predetermined image process is executed for image data corresponding to the handle, and the processed image data is supplied to the printing device.