A table is allocated indexes corresponding to display positions on a monitor screen, respectively, and data indicating an unexposed part at each of the display positions is stored in each index of the table. Focal position information is acquired from Exif header information on image data of an image, and a location of one of the indexes in the table at which no image data is registered is searched in an ascending order of the indexes. According to the table, the images are arranged so that the focal position of each image differs from the unexposed part at the display position of the image.