| 摘要 |
A method for authenticating a printed document is disclosed. Barcode stamps are added to an original document image near the corners of the page to act as registration markers. The original document image bearing the barcode stamps is printed and circulated, while the original document image is stored in a database. To authenticate a printed document, the printed document is scanned into a target document image, which is compared to the stored original document image. The barcode stamps are used as registration markers to perform a global image registration. Then, the target image and the original image are divided into multiple sub-images, and local image registration is performed on the sub-images before performing an image comparison. Difference sub-images are generated from the pairs of sub-images, and merged into a global difference image for the purpose of detecting any alterations in the printed document. |
