A composite image is generated by a method including: detecting at least one in a captured image; judging arrangement of the at least one subject by an arithmetic operation; selecting at least one composition-purpose image at random in accordance with the arrangement of the at least one subject; determining arrangement of the selected at least one composition-purpose image at random so that the at least one composition-purpose image does not overlap with one another and does not overlap with the detected at least one subject; and generating a composite image by combining the captured image with the at least one composition-purpose image.