Patent ID: 8363889

Claim:
An image data processing system, comprising: an image input module, receiving an image and a secret information and obtaining at least one gray-level image according to the image; a bit map generation module coupled to the image input module, generating a bit map image according to the gray-level image and generating an ordered dithering block truncation coding (ODBTC) image according to the bit map image and the gray-level image, wherein each pixel of the bit map image is black or white; and an encoding module coupled to the image input module and the bit map generation module, generating an encoded gray-level image according to the bit map image and the secret information, wherein the encoding module divides the gray-level image into a plurality of image blocks, finds candidate blocks with close black and white pixel numbers among the image blocks, selects high frequency blocks belong to the high frequency region of the image from the candidate blocks, and randomly embeds the secret information into the high frequency blocks to generate the encoded gray-level image with the secret information embedded therein, wherein the encoding module further comprises a high frequency block analyzing unit and the high frequency block analyzing unit further finds the candidate blocks with close black and white pixel numbers among the image blocks by the following formula: |#black pixel−#white pixel|< BW Th , wherein #black pixel represents a total number of black pixels within a block, #white pixel represents a total number of white pixels within the block and BW Th represents an adjustable threshold parameter.