Patent ID: 8120795
Filing Date: 2012-02-21
Classification: G03G,H04N

Abstract:
1. A method of document protection, comprising the steps of: (1) generating a document by forming a layer of authentication shade underneath an original image; (2) obtaining a digitized image file of the document by a copy apparatus when the document is processed for copying; (3) scanning the digitized image file to detect, by operating a program fixed in the copy apparatus, whether a watermark is included in the document; and (4) prohibiting the document from being copied if the watermark is detected in the step (3); or copying the document if no watermark is detected and outputting a duplicate document through a hardware controller of the copy apparatus, wherein the authentication shade includes a background pattern area and a mark area, the background pattern area is a halftone image, and the mark area is formed by repeating one mark on a whole page so that shapes and positions of the repeated marks constitute the watermark which is distributed in the document to be detected.