Novel digital watermarking method capable of maintaining fidelity and robustness

Abstract

The invention discloses a novel digital watermarking method capable of maintaining fidelity and robustness. An embedded algorithm serves as main content, and at first, an original image is segmented into subblocks which are distributed in eight rows and eight columns and are not mutually covered; then discrete cosine transformation is carried out on each subblock; finally, maximization of integrity of watermark information extracted from figures which contain watermarks and are attacked serves as a goal, and under the constraint that the PSNR is larger than 25dB, the watermark weighted value of each subblock is optimized to obtain the optimal solution which serves as the final watermark embedding scheme. On the condition of guaranteeing fidelity of digital watermarking, watermark robustness is optimized by means of an evolutionary optimization algorithm, the fidelity and robustness are taken into full consideration, digital watermarking quality is improved, degradation of images formed after the watermarks are embedded is difficult to perceive compared with that of the original image, and good robustness is achieved against attacks such as compression, filtering and zooming rotational shearing.

Description

technical field [0001] The invention belongs to the technical field of digital watermarking, and in particular relates to a novel fidelity robust digital watermarking method. Background technique [0002] At present, in terms of improving the fidelity and robustness of digital watermarking, for fidelity, it is generally to find the watermark embedding scheme with the least visual damage in the original data through optimization algorithm; for robustness, it is also to find a suitable frequency band to embed watermark through optimization algorithm , so that it can still not lose the watermark information when it is attacked. Fidelity and robustness are two mutually restrictive factors, neither of which can be discarded, and it is necessary to seek the unity between them, and make the watermarking system optimal under the constraints of this unity. [0003] The existing digital watermarking technology generally improves the fidelity through the optimization algorithm, but le...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a new fidelity robust digital watermarking method, aiming to solve the problem that the existing digital watermarking technology generally improves fidelity through optimization algorithms, but less consideration is given to the use of optimization algorithms to improve robustness , under the premise of ensuring the fidelity of the digital watermark, the evolutionary optimization algorithm is used to optimize the robustness of the watermark, and the fidelity and robustness are considered comprehensively to improve the quality of the digital watermark

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