Anti-printing and scanning watermark algorithm for two-value text image based on row space and word space

Abstract

The invention discloses a new blind watermark algorithm for a two-value text image, which mainly solves the problems of low watermark embedding capacity, non-blind extraction mode, easy discovery and the like in traditional word shift coding and row shift coding. The watermark algorithm of the invention comprises the realizing steps of: respectively extracting row space and word space in the two-value text image; respectively forming a one-dimensional row space vector and a word space vector by using a row as a main sequence; performing the operation of scrambling, blocking, modulating and inverse scrambling respectively on the row space vector and the word space vector in a watermark embedding process; finally, modifying the size of the row/word space of the two-value text image; and obtaining watermark information for embedding the two-value text image only by respectively performing the operation of scrambling, blocking and demodulation on the row space vector and the word space vector when extracting a watermark. The algorithm enhances the watermark embedding capacity on the premise that high invisibility and strong robustness of the watermark are ensured compared with the traditional word shift coding and row shift coding; and moreover, the embedded watermark information is robust for printing, duplication and scanning channels.

Description

technical field [0001] The invention belongs to the technical field of digital watermarking, and relates to the embedding and extraction of binary text image watermark information, in particular to a new blind watermarking algorithm for binary text images, which ensures the high invisibility and high invisibility of the watermark Under the premise of strong robustness, the watermark embedding capacity is improved, and the embedded watermark information is robust to the printing and scanning channels. Background technique [0002] With the popularization of the Internet and the development of digital communication equipment, information sharing has become a trend. The global village facilitates the sharing of documents, images, videos and various resources among people; at the same time, concepts and information exchange methods such as e-commerce, e-government and digital libraries have been accepted by the public. E-commerce and e-government need to transmit a large number...

AI Technical Summary

Problems solved by technology

[0013] The purpose of the present invention is to address the low embedding capacity, non-blind watermark extraction mode, high visibility after watermark embedding, and watermark embedding and extraction system existing in the existing binary text image watermarking algorithm based on line-shift coding and word-shift coding Complex and other deficiencies, a binary text image watermarking algorithm based on word space and line space that is robust to printing and scanning channels is proposed

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