Research On Text Watermarking For Texts Mixed Chinese And English

With the development of computer network technology, it is more and more popular to use digital multimedia. It brings a new challenge to copyright protection of digital information. Digital watermark technology is becoming a hot area as special technology of digital production copyright protection. Most existing digital watermark researches have been concentrated on images, audio and video. However, many text document is more valuable than multimedia such as image, video etc. Now a lot of documents exchange on Internet, and they ask for effectual digital watermark technology very badly.The research on text digital watermark in China is very limited. Most algorithms are concentrated on Chinese text and English text. But as far as the writer knows, no research has been done on text mixed Chinese and English until now. And there is no one special digital algorithm for document that Chinese and English both exist. Aim at this application limitation, this paper proposes a text digital watermark algorithm for text mixed Chinese and English. The algorithm makes use of character attribution and character code to embed the watermark information. And the particular procedure of embedding and extracting are designed. The algorithm proposed in the paper combines some foundation theory such as digital watermark basic model theory, HVS theory, error control code and cryptography, etc. Making use of these foundational theories has enhanced the invisibility and security performance of text digital watermark.After the proposal and design of text watermark, a text watermark program is implemented by Visual C++6.0.This program is applied for Word document mixed Chinese and English that created by MS Word 2003. The text watermark algorithm is tested by using the watermark program. The test concludes function test, invisibility test, watermark capacity test, robustness test and security test. Mostly attack that text watermark suffered are simulated to test performance. This paper also analyzed the performance in the test result and in theory. Finally, there comes a conclusion that the text watermark algorithm on the paper has excellent invisibility, large watermark capacity, better robustness and security. This paper works on the experiment conclusion, and proposes some improve measures. Base on the research, a class of algorithm applied for text mixed Chinese and English is proposed and analyzed in theory. The algorithm class is very flexible, and it can supply many different individual embedding algorithms while facing different application.The text digital watermark algorithm and algorithm class for text mixed Chinese and English in this paper is a useful way of solving the problem of existing text watermark can not be applicable for two languages both exist. And it provides some suggests and experiment foundation for research on text watermark algorithm for text mixed different language.