| 摘要 |
PROBLEM TO BE SOLVED: To provide a device capable of detecting tampering in a grant document with a sufficient accuracy, even if the grant document is dirty because of dust etc. SOLUTION: A grant document generator 100 specifies an important area containing an object to be protected in an inputted document image, and generates area protection information, which is protection information for every specified important area. The generator 100 embeds the area protection information into the background of the object to be protected at the important area in the inputted document image as a protection pattern, and stores the coordinate of the area protection information and the important area. The generator 100 builds up detection information for tampering detection according to the coordinate of the area protection information and the important area, and generates and embeds an image for detection based on the detection information. On the other hand, a grant document confirmation device 101 takes out the detection information from the image for detection. The device 101 specifies the important area and extracts the protection pattern based on the taken-out detection information. The device 101 extracts the area protection information from the protection pattern. The device 101 compares the area protection information extracted from the protection pattern with the area protection information stored at the image for detection, and determines whether tampering has been done in the grant document or not. COPYRIGHT: (C)2011,JPO&INPIT
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