Study On Watermarking Techniques Of Digital Images Based On Wavelet Transform

Copyright protection receives much concern both at home and abroad, and some problems related to it are difficult to solve, especially to the protection of digital media copyright. These digital media including images, characters, audio and video digitalized works are easy to store, design, transmit and duplicate, and accelerate communication and transmission of knowledge and information. While it offered convenience to some illegal persons who can distort, attack and pirate the achievement maliciously at the same time. With the rapid development of internet, multimedia and communication technology, protection of digital media copyright has been paid more and more attention, which makes technology of digital watermark concerned by people extremely. As a novel technology, digital watermark rises in recent years, and offered brand-new thought to realize effective protection of intellectual property. Now it has become a research hotspot in the field of multimedia information security.Watermark technology and its application of digital image is comparativelyanalyzed and studied in this thesis. It mainly includes the following several aspects:1. Recapitulative summary and analysis of basic technology of digital watermark is presented from the origin, state of art, basic principles, characteristics and classifications of watermark.2. Summary and discussion of detection technique of digital watermark embedding is carried out. Several handling strategies of concrete watermarks are put forward through analyzing each image compressing and coding method.3. An algorithm of watermark based on wavelet transform domain is put forward,which embeds watermark into wavelet transform domain according to its owncharacteristic of image and has excellent invisibility and robustness.4. An algorithm of watermark is put forward. It embeds watermark via masking characteristic of human vision texture, luminance and blue channel. This algorithm ensured the invisibility of watermark and demonstrated better robustness in common image processing.