IMAGE PROCESSING METHOD, IMAGE ZONE DETECTION METHOD, RECORDING MEDIUM STORING IMAGE PROCESSING PROGRAM, RECORDING MEDIUM STORING IMAGE ZONE DETECTION PROGRAM, IMAGE PROCESSING APPARATUS AND IMAGE ZONE DETECTION APPARATUS

摘要

PPROBLEM TO BE SOLVED: To provide an image processing method with which changes in appearance are minimized for a rectangular image in which a code is embedded, and when the image is picked up and fetched, four corners of its rectangle is easily specified. PSOLUTION: In an image processing method of the present invention, regarding pixels within a region designated inside a rectangular image at four corners, a gradation level (for a color component corresponding to a complementary color of yellow) is changed so as to maximize, around a pixel to be processed, a difference between the gradation level of the pixel to be processed and a gradation level of a pixel in a background region. Namely, the gradation level is reduced. This means that a pixel looks yellowish as a result of performing gradation level change processing. Since yellow is hard to be recognized for human eyes, the change performed on the pixel becomes hardly conspicuous in comparison with the case where a mark or a frame is arranged outside the rectangular region. PCOPYRIGHT: (C)2009,JPO&INPIT