IMAGE PROCESSING METHOD AND IMAGE PROCESSING APPARATUS

A CG image having a transparency parameter is superimposed on a shot image, which is an image picked up by an image-pickup device, to obtain a combined image. The combined image is displayed in a combined-image-display region. In the combined image, a mask region of the CG image is set based on parameter information used to extract a region of a hand. The transparency parameter of the CG image is set based on a ratio of the size of the region of the CG image excluding the mask region to the size of the shot image. By checking the combined image, which is displayed in the combined-image-display region, the user can set the parameter information by a simple operation.