Full blind digital watermarking method with copyright protection and tampering positioning functions

Abstract

The invention discloses a full blind digital watermarking method with copyright protection and tampering positioning functions. The method comprises the following steps: dividing an approximation sub-graph of an original gray level image into non-overlapping 8*8 sub-blocks, and dividing each sub-blocks into 4*4 areas; performing discrete cosine transform on each area; creating a feature watermarkand a self-embedded feature watermark according to discrete cosine transform coefficient matrices of different areas; performing discrete cosine transform on each area in each sub-block in the approximation sub-graph of a watermark image in the same manner during extraction; then extracting the feature watermark and an authentication watermark according to the discrete cosine transform coefficientmatrices of different areas; and calculating a normalized correlation coefficient between the feature watermark and the authentication watermark for copyright protection, and comparing the feature watermark with the authentication watermark bit by bit to achieve full blind tampering positioning. The full blind digital watermarking method has the advantages that only one digital watermark needs tobe embedded to realize the double functions of copyright protection and tampering positioning, any information of the original image and the original digital watermark is not required during the extraction of the watermark, and full blind detection of the watermark can be achieved.

Description

technical field [0001] The invention relates to a digital media information security technology, in particular to an all-blind digital watermarking method with functions of copyright protection and tampering positioning. Background technique [0002] With the rapid development of digital media and network technology, digital watermarking technology has become an effective means of media copyright protection and content integrity certification. However, most of the existing digital watermarking technologies are single-watermarking algorithms, which often have the limitation of single function, that is, only copyright protection or content authentication can be realized. Obviously, multi-functional digital watermarking algorithms have stronger demands in practical applications. [0003] Multifunctional digital watermarking refers to embedding different watermarks in the same digital image to achieve different application purposes. For example: Embedding a visible watermark a...

AI Technical Summary

Problems solved by technology

Obviously, compared with the single watermarking algorithm, the simultaneous embedding of double watermarks will inevitably lead to a decline in image quality; interference, thus affecting the extraction effect of the subsequent watermark

In addition, in order to realize functions such as copyright protection and content authentication, the correlation measurement and comparison between the extracted robust watermark and fragile watermark and the original digital watermark are required, and the blind detection of digital watermark cannot be realized.

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