The image processor includes: an acquisition unit acquiring a read-out image read out by an image reading apparatus; a detection unit detecting, from the read-out image, an embedded image including a first specified image having a first shape and a second specified image having a second shape; an adding unit adding attribute information to a specified region in the embedded image, in accordance with an appearance ratio of the first specified image in the specified region, and adding attribute information to other region surrounding the specified region, in accordance with an appearance ratio of the first specified image in the other region; and a determination unit determining whether or not the specified region is to be subjected to a predetermined processing using the first specified image based on whether or not the attribute information added to the specified region corresponds to the attribute information added to the other region.