Jpeg2000-based Digital Watermarking Research

With the development of multimedia and network technology, it is very important question for the effective transmission and information security of digital multimedia product. As the pivotal techniques correlative to above issues, the coding technique and digital watermarks of multimedia data attract a lot of researchers. Digital watermarking technique is a branch of information hiding. In recent years, research on information hiding techniques including digital watermark has made great progress and its range of application has been expanded gradually.JPEG2000 is a new generation international compression standard for still image, which has not only better coding efficiency, but also some good characteristics that suit Internet applications, such as the traits which support progressive coding, flexible processing on codestreams, etc. The research object of this thesis is to make a combination between watermarking algorithm and JPEG2000 encoding decoding system, and then propose authentication watermarking algorithm combined with JPEG2000. It is fitted for the authentication issues that the transmission and exchange of images on the web.In this paper, first, an introduction of digital watermarking's basic theory is given. Then the advantages and disadvantages of current watermarking algorithms as well as their application fields will be discussed. And then JPEG2000 encoding decoding system is analyzed, the request that based on JPEG2000 digital watermark is introduced. An authentication semi-fragile watermark algorithm is introduced based on full utilization wavelet transform and EBCOT that JPEG2000 offerred. In the algorithms, the watermark is inserted into the high frequency of wavelet coefficients quantified, which has little effect with JPEG2000 encoding decoding system. At last, the test result of the algorithms is given, and analyzed. Experiments indicate that the algorithm has robustness on the rate smaller than 1:10 JPEG2000 compression, has a fragile on the usual attacks e.g.:shearography, noise, sharpen, faintness.