Research On Binary Text Image Digital Watermarking Technology

With the popularization of Internet and the development at full speed of themulti-media technology, the copyright protection of digital works has already becomethe hot issue at present. Generally speaking, image, audio and video watermarking is comparatively similar in algorithm realization, with their redundancy and the trait of HVS (Human Video System) or HAS (Human Audio System), in which we can embed watermark. But other than the aforementioned, there is no redundancy to transfer secret info in text document. Nowadays, to embed watermark in text documents are limited to methods such as shifting the line and word, amending the characters'traits and disposing in the level of semantics. All these algorithms are not robust or lack of concealment, generally not serving the turn of Chinese text documents rifely.Based on the studies of the documents digital watermarking methods and techniques, this dissertation presents that the problems of existed ducouments watermarking algorithms can be solved by Non-wartermarking technique. Centering on this topic, the main aspects of research include:1. Firstly comprehensive study of the existing document watermark algorithms, as well make analysis and comparison of them.2. An algorithm based on the block of pixels banging watermarking algorithm, are analyzed and improved, that make the algorithm more responsive to the Chinese documents. The experimental results showed that the proposed method robust for noise attack.3. Based on the analysis of the existed algorithms, the dissertation aggregate the difficulties of document watermark algorithm: First, due to the special nature of the text, making contradictions between embedding capacity and hidden; Second, most algorithms are largely based on the current text format changes which do not affect the original vector of quality, so robustness is generally poor. Therefore, this paper present the idea that appliny non-watermarking to the doucument watermarking, and draw conclusions as: The non-watermarking algorithm can just solve contradiction the problem between capacity and hidden; As carriers with no need to amend, non-watermarking algorithms may use any method and structure without having to consider watermark embedding capacity, so it has higher robust than other document watermark algorithms. 4. Moreover, the dissertation raises two algorithms, of which integratiny Logistic mapping and constructing watermark with DWT and DCT transformation, respectively, and detect with similar tests being detected.In this dissertation, is achieved the proposed watermarking algorithm and nalysis and comparison of the two algorithms illashated by a large number of attacks experiments, the Experimental results show the robustness is hill, but the false alarm rate should be improved. At the end of this dissertation, sum up the whole paper and point out the direction of future research.