Text numerical watermark method for resisting analog domain attack

Abstract

The present invention relates to a text digital watermarking method against analog domain attack, comprising the following steps: a) preprocessing before embedding watermark: dividing, merging and screening the word blocks in the original text image to form a watermark embedding word block sequence; b ) Watermark embedding: Embed the binary sequence of watermark information into the sequence of watermark embedding blocks selected from the original text image, and embed 1 bit of watermark information through the horizontal shift of the position of each watermark embedding block; c) extract Preprocessing before watermarking: Divide the watermark image into the same blocks as in a), use the original text image to assist in generating and locating the watermark embedding block sequence and its positioning block sequence in the watermark image; d) watermark extraction and judgment: according to The shift of the word block extracts the watermark information and makes a judgment. The watermark information embedded in this digital watermarking method has strong robustness, and the text after embedding the watermark has good aesthetics and watermark concealment.

Description

technical field [0001] The invention relates to an information hiding technology, in particular to a text digital watermarking method against an analog domain attack, and belongs to the technical field of security authentication. Background technique [0002] As a novel information hiding technology, digital watermarking provides a new solution to solve a series of problems such as copyright protection, source authentication, tampering authentication, online distribution, user tracking and identity authentication on the open network. But now people mostly focus on the research of digital watermarking technology for digital images, audio and video, but few researches and applications related to digital watermarking algorithms with text images as carriers. However, the application requirements of text digital watermarking are very urgent, especially for institutions such as national administrative agencies and large commercial organizations, which often need to distribute docu...

AI Technical Summary

Problems solved by technology

[0003] 1) The text image can represent the whole image with only a few simple colors. There are almost no textures and details at all, and some are just different geometric shapes. It is difficult to design an algorithm that meets the requirements of digital watermarking with such a carrier;

[0004] 2) Most of the text images are continuous area blocks with the same color value or gray value. If the usual method of modifying the color or gray value of some selected pixels is used to embed watermark information, it may result in the same color value. Or there are pixels of different colors or brightness perceptible to the naked eye in the gray value area, which destroys the concealment of the digital watermark and the aesthetics of the text;

[0006] The existing general electronic encryption technology or digital watermarking algorithm have not solved the above difficulties well.

Images