IMAGE PROCESSING DEVICE, IMAGE PROCESSING METHOD, IMAGE PROCESSING PROGRAM, AND MECHANICALLY READABLE RECORDOING MEDIUM CONTAINING THE IMAGE PROCESSING PROGRAM

摘要

A printer for processing an image to be output generates a random dot image where points are arranged at random (S10-S12) and performs exclusive OR calculation between each corresponding pixels between the generated random dot image and a first mask image (32) prepared in advance, thereby generating an encrypted image (S13). The generated random dot image and the encrypted image are subjected to processing such as geometric conversion so that the corresponding pixels are matched when they are superimposed and printed out (S15). When the images are superimposed by the exclusive OR calculation and output, the first mask image (32) embedded in the encrypted image via the random dot image appears visually. Only the image in which the first mask image (32) can be viewed is authenticated to be a genuine one. Since this superimposing accuracy cannot be obtained by a normal copying machine, it is possible to prevent forgery.