Wavelet-based geometric attack resistant digital watermark method

Abstract

The invention discloses a digital watermarking technique based on wavelet transformation, which comprises: taking wavelet transformation to original image to embed a watermark into the coefficient of an approximate subgraph for global DCT operation to find out an image feature vector robust to geometrical attack; taking wavelet transformation to the tested image and global DCT operation to the approximate subgraph to find out a feature vector of the tested image for its watermark extracting. This invention has well resistant performance to rotation, reduce and enlarge, and distortion.

Description

technical field [0001] The invention relates to a digital watermark technology based on discrete wavelet transform (DWT) and image visual features, is a multimedia data protection method, and belongs to the field of multimedia signal processing. technical background [0002] At present, digital watermarking is one of the effective methods to protect digital media copyright. At present, most watermarks can only resist conventional attacks such as compression and filtering, and are helpless against common or even tiny geometric attacks. In recent years, some foreign scholars have done some theoretical research on anti-geometric attack watermarking algorithm, but the effect is not ideal. Pereira et al. used the template insertion method, but the template embedding and extraction method is more complicated, the embedded information capacity is small, and the embedded template is vulnerable to attack; O'Ruanaidh et al. based on the Fourier-Mellin transform, ...

AI Technical Summary

Problems solved by technology

In recent years, some foreign scholars have done some theoretical research on watermarking algorithms against geometric attacks, but the effect is not ideal.

Pereira et al. used the template insertion method, but the template embedding and extraction method is more complicated, the embedded information capacity is small, and the embedded template is vulnerable to attack; O'Ruanaidh et al. based on the Fourier-Mellin transform, using this transform to have RST (Rotate, Scalling, Transtation) invariance realizes the anti-geometric attack ability of watermarking, but this method makes the quality of watermarking image poor; ability to rotate and embed less information

[0003] Therefore, anti-geometric attacks are currently a challenging problem. In particular, Voloshynovskiy et al. pointed out in the article that local arbitrary distortion attacks are a more complex type of geometric attacks. At present, almost no effective anti-attack methods have been published.

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