Study On Watermarking Of Digital Images And Its Correlative Techniques

The rapid development of the Internet has paved the way for the transmission of multimedia data. However, it caused difficulties in copyright protection of digital media on the Internet. As a kind of newly arisen copyright protection technology, the digital watermarking has already become the hotpot of the domestic and international research in recent years.In this thesis, more research and analysis of the digital watermarking about digital images was given. Primary work includes the following three aspects:1, Some basic knowledge of the relevant digital watermarking is presented, including its background, basic system structure, basic principle, characteristics, categorize, state-of-the-art development, applications and so on. The familiar digital watermarking attack technique is discussed. It will contribute to further of watermarking research2, Some related technology of the digital watermarking is discussed. The solutions which aim the problems met in the research are put forward. These include four parts: A Fibonacci reverse transformation formula and a FPS reverse transformation formula are derived. With the formulas, it becomes easy to get the reverse transformation result in processing images; A new method of detecting binary value digital watermarking is put forward. It can detect binary value watermarking more exactly; A method of processing extracted digital watermarking is put forward. With this method, the result of detecting digital watermarking will be more accurately; An general method of watermark capacity estimation for digital watermarking is given. For a given image quality evaluation metric, the watermark information capacity can be computed or estimated precisely, or up to an upper bound.3, An improved adaptive algorithm based on discrete wavelet transformation for watermark embedded in digital images is presented. It takes advantage of features of human visual system, including luminance masking and texture masking, and has much better imperceptibility and robustness against general image processing and noise interference.