Image processing device and image processing program

A printed document sheet is made to exhibit functions that read out embedded information, detect forgery and falsification and carry out copy restraint. From a design determined by a restraint design(11) a restrain image (13) with predetermined restraint points of positions, sizes and colors is generated. Meanwhile, after a part of a background texture is eliminated from a background texture watermark image (12) with a document, a background texture eliminated image (14) is generated. The restraint image (13) and the background texture eliminated image (14) are synthesized to generate a synthesized image (15). A printed document as the synthesized image (15) does not mutually cause interference between a background texture effect and a restraint effect and is the one with a very high degree of security that sufficiently exhibits functions that read out embedded information, detect forgery and falsification and carry out copy restraint.