A CPU 200 obtains and analyzes one or multiple image data GD, which are to be laid out on ornamental image data FD. The CPU 200 also obtains and analyzes desired ornamental image data FD to acquire a color distribution characteristic (representative color Fc). The CPU 200 sets an analyzed correction level according to the result of the analysis of the image data GD and modifies the analyzed correction level based on the acquired color distribution characteristic, so as to set a modified color balance correction level. The CPU 200 adjusts the color balance of the image data GD with the modified color balance correction level and pastes the color balance-adjusted image data GD onto the ornamental image data FD according to layout control information LI to generate output image data.