Digital Watermarking Theory And Application Of Technology

The digitization of multimedia data provides more convenience for the storage of multimedia information, and at the same time, it improves the efficiency and correctness of the expression of the information. With the burst application of Internet, the mass exchange of multimedia information has grown to a higher level, and the information has thousands of ways to be expressed. People are able to issue their works and important information via Internet and even trade with one another. The convenience brings serious problems: works are easier to be pirated and revised. So how to get advantage of Internet and meanwhile protect the knowledge of properties of right effectively is extremely important. This requirement gives up to a new cross-study field: digital watermark. Digital watermark is a new and effective way to protect digital products and to maintain the data security. It is a very practical information hiding technique. Watermarking utilize a digital method to embed some markers which have special meanings into digital images, audio, documents, books and video. Watermarks can testify the ownership of the above. What is more, watermarks can also be the evidence in front of the court. In a word, digital watermarks can be an effective method to protect knowledge property and multimedia data. However, watermarks should not destroy the usefulness and the value of being viewed of the original data. Now any companies have developed digital ideograph systems and put them into operation in electronic business, digital works dealing systems, video processing systems. Digital watermarks have also find its usage in military secret communication and communication counterwork. Watermarks are used in copyright protection, and its potential use lies in electronic business, online or off-line distribution of multimedia data and mass digital broadcasting. Watermarks are used to hide markers, and its applications include medical examination, drawing, digital imaging, digital video watch, multimedia index and content-based searching.In this paper, we design and realize three watermarking algorithms based oncomplex wavelet transform, multi-band wavelet transform and integer wavelet transform. And then we make some primary discussion and attempt on watermarking algorithm based on dirty paper coding.We organize the paper as below: The first chapter introduces the concept, definition, application and some attack method of watermarking. The second chapter introduces the concept, definition of some kinds of wavelet, and we also show the programming realization of these kinds of wavelet transformation. The third chapter introduces the development of digital watermarking and the application of wavelet in the field. In the forth chapter realize three watermarking algorithms based on complex wavelet transform, multi-band wavelet transform and integer wavelet transform, and set up one watermarking system based on dirty paper coding The last chapter is the conclusions, summarization of our work and future study.