Digital image watermarking method based on local index torque characteristic

Abstract

The invention discloses a digital image watermarking method based on the local index torque characteristic. Characteristic points of an original image are extracted and screened through brightness probability density gradient Harris-Laplace operators, and a screened characteristic point image is obtained; in the obtained characteristic point image, round areas with the characteristic points as circle centers are extended into square areas, and local characteristic areas are constructed and screened; the index toque of the obtained local characteristic area image is obtained through calculation, needed stable index toque is selected, the amplitude values of the index torque are modified with a quantization index modulation method, and watermarking information is embedded; the selected index torque is respectively reconstructed before or after the watermarking information is embedded, two reconstructed images are obtained and subjected to difference value calculation, the obtained difference values are overlaid into the local characteristic areas corresponding to the original image, and small images with watermarks are obtained; watermarking information is embedded into all the local characteristic areas.

Description

technical field [0001] The invention relates to the fields of digital multimedia anti-counterfeiting and information security protection, in particular to a digital image watermarking method based on local exponential moment features that can effectively resist desynchronization attacks. Background technique [0002] With the rapid development of network technology and digital media technology, the transmission and utilization of digital information has become increasingly frequent and widespread. Since digital information is easily edited, copied and distributed without restriction, the encryption of digital works has become increasingly prominent. . Digital watermarking (Digital Watermarking), as an effective supplementary method to traditional encryption methods, is a new technology that can protect copyright and authenticate the source and integrity in an open network environment. A hot spot of research. The so-called digital image watermark is to hide a mark (watermar...

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Problems solved by technology

Among them, the exhaustive search scheme has the disadvantages of large amount of calculation and high false alarm rate; the scheme of combining spread spectrum watermark with spreading code cannot realize the blind detection of watermark information; More complex general desynchronization attacks such as ratio conversion and local affine distortion; the synchronous correction scheme has weaknesses such as limited watermark capacity and high time complexity; The stability of feature points is poor and the distribution is extremely uneven, the color image feature point detection operator is scarce, the constructed local feature area does not have complete affine invariance, and the capacity of digital watermark is too small, etc.

[0004] So far, there is no relevant report on digital image watermarking methods based on local exponential moment features

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