Method and device for embedding and detecting watermark in document by using computer system

Abstract

The invention relates to method and device for embedding and detecting a watermark in a document by using a computer system, in particular to method and device for loading a document watermark to an electronic text document by using a computer program so as to protect the electronic text document, belonging to the technical field of document protection. The computer program at least comprises the generation of the electronic text watermark, the loading and embedding of the watermark and the detection of the watermark. The method comprises the following steps of: firstly, generating watermark information from copyright information prepared to be added into the electronic document by using a watermark generating module; then, reasonably optimizing the analysis of a watermark carrier medium, the preprocessing of embedded information, the selection of an information embedding point, the design of an embedding mode and the control of embedding modulation by using a watermark loading and embedding module; and equivalently transforming set natural language semantics to embed the watermark through reasonably selecting a secret key. If a copyright dispute happens, a watermark detection module designed in the invention can be used for detecting and extracting the document watermark of the electronic document by using the preset secret key, and the result shows that the document watermark embedded in advance can provide an identification basis for solving the electronic document copyright dispute. Thus, the invention can be widely applied to document protection encryption, tracking, illegal distribution control and technical protection of copyrights.

Description

technical field [0001] The invention belongs to the technical field of digital watermarks, in particular to a method and device for embedding and detecting digital watermarks in text documents. Background technique [0002] With the advent of the information age, digital multimedia products play an increasingly important role in people's work and life, and the dissemination of digital works has reached unprecedented depth and breadth. Especially with the rapid development of computer network technology, digital communication technology, information coding and compression technology, the exchange and transmission of digital content has become very simple and fast. People can use computers, digital scanners, printers and other electronic equipment to facilitate, Quickly convey digital information to anywhere in the world. However, due to the characteristics of easy copying and dissemination of digital products, piracy and infringement incidents are common. Therefore, how to u...

AI Technical Summary

Problems solved by technology

The robustness is poor, and this information hiding algorithm is generally only applicable to documents

(2) Based on the algorithm of spaces and punctuation marks, the method of embedding watermark information in spaces, although the embedded spaces are not easy to find, but some text processing tools have the function of automatically deleting redundant spaces, which will lead to the destruction of secret information

The problem with embedding algorithms that change punctuation is that inconsistent use of punctuation can be spotted by careful readers, and changes in punctuation can affect the clarity and even meaning of text content

(3) Algorithms based on the characteristics of Chinese characters. This algorithm has relatively high capacity and robustness, but they are all proposed for binary text images. For our most common daily text documents, they are not achievable.

If you use this kind of algorithm, you must use a special font library, which has poor versatility and is only suitable for documents such as PDF

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