Image features of a plurality of RGB images arranged for layout are extracted, and the RGB images are classified into image categories determined by the commonality of the image features. Recipe information previously set in accordance with the image features is added to layout data while being associated with RGB images for each image category. This enables an output device to perform an optimization process by reference to the added recipe information, thereby outputting good-quality printed matter excellent in color reproduction and the like if information for the process of optimizing RGB image data is not previously provided during the generation of the layout data.