Text image watermark embedding method, text image watermark embedding system, text image watermark extracting method and text image watermark extracting system

Abstract

The invention provides a text image watermark embedding method and system, and a text image watermark extraction method and system, and the text image watermark embedding method comprises the steps: carrying out the secondary encryption of an input watermark, and obtaining a watermark to be embedded through error correction coding; performing secondary discrete wavelet transform on the text imageto obtain four first frequency band coefficient matrixes; performing block discrete cosine transform on the first frequency band coefficient matrix to obtain a corresponding first block coefficient matrix; for each first block coefficient matrix, selecting an intermediate frequency coefficient, and embedding a watermark by modifying the coefficient to obtain each first block coefficient matrix embedded with the watermark; and performing inverse discrete cosine transform and inverse discrete wavelet transform on each first block coefficient matrix embedded with the watermark to obtain a text image embedded with the watermark. According to the embodiment of the invention, on the premise that the invisibility of the watermark is ensured, the robustness of the watermark for resisting attacks such as compression, noise and shearing and the algorithm security are improved.

Description

technical field [0001] The invention belongs to the field of digital media copyright protection, and in particular relates to a text image watermark embedding method and system, and an extraction method and system. Background technique [0002] With the development of Internet technology and the rapid popularization of digital information, the dissemination of digital media has become increasingly widespread. Digital media has the characteristics of easy dissemination and low cost. While people obtain digital media conveniently, they also face the risk of digital media content being pirated and tampered with. Therefore, it is necessary to properly deal with digital media before it is released. Digital watermarking technology is an effective digital media copyright protection technology, which can verify piracy and tampering behaviors and realize copyright protection of digital works. As a commonly used digital medium, the research on its watermarking technology is constantl...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the above-mentioned problems in the prior art, that is, in order to solve the problems of invisibility, robustness, and algorithm security of the watermark,

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