Image watermark embedding and extracting method combining ridgelet transformation and DCT (Discrete Cosine Transform)

Abstract

The invention discloses an image watermark embedding and extracting method combining ridgelet transformation and DCT (Discrete Cosine Transform). The watermark embedding method comprises the following steps of transforming an image from an RGB (red, green and blue) space to a YIQ (Luminance and Chrominance) space; performing ridgelet transformation on the Y component; selecting an embedding frequency band and dividing into blocks; performing DCT, and adding watermark information to obtain a DCT factor matrix which contains the watermark information; performing IDCT (Inverse Discrete Cosine Transform) and inverse ridgelet transformation; and transforming the image from the YIQ space to the RGB space to obtain the image into which a watermark is embedded. The watermark method comprises the following steps of transforming the image from the RGB space to the YIQ space; performing ridgelet transformation on the Y component; selecting the embedding frequency band and dividing into blocks; performing DCT; extracting the watermark; and calculating a quantized value to obtain the watermark image. The robustness of the watermarking algorithm is enhanced, and the method has higher robustness and invisibility.

Description

technical field [0001] The invention relates to a digital image watermark technology, in particular to an image watermark embedding and extraction method combining ridgelet transform and DCT. Background technique [0002] With the rapid development of my country's cultural and creative industries, intellectual property protection has become an important guarantee for the development of cultural and creative industries. The creative industry is a derivative development industry based on copyright. The core of the creative industry is copyright. Therefore, only by doing a good job in copyright protection can the creative industry take off in China. [0003] Every year, a large amount of digital information is infringed and pirated around the world, and piracy poses a serious threat to the authenticity and integrity of digital information. If the information involves government confidentiality, judicial proceedings, medical records, e-commerce and other special applications, i...

AI Technical Summary

Problems solved by technology

[0020] 1. Algorithms with a single function cannot have good robustness and sensitive vulnerability at the same time;

[0021] 2. The invisibility of the double watermark method is poor;

[0022] 3. DCT cannot reflect the edge and contour information of the original image; DWT does not fully consider the directionality and singularity of the image edge, and has poor resistance to geometric attacks; ridgelet transform cannot resist a greater degree of geometric attacks

[0023] 4. The digital image watermarking algorithm combining DWT and DCT does not consider the problem of linear singularity, and its robustness is poor

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