Information Hiding Researth Based On Digital Watermark

The electrical commerce is more and more popular, that challenge the traditional method of copyright protection and technology of data security. Digital watermarking technique is an effective protection technique, Which embeds a copyright information into multimedia products in order authenticate the ownership or transmit to the available information.In this thesis, I introduce the purpose and meaning of my study in this field and also introduce the definition, characteristic, class and use firstly.Then I introduce the primary watermarkattacks and their relevant countermeasures.And then I introduce the basic theories of wavelet transform, including continue wavelet transform, delete wavelet transform, multi-resolution analysis and Mallat algorithm and so on.The passage analyzes the advantages of using wavelet transform in digital watermarking and multi-resolution analysis, puts forward a new kind of watermarking schemes in DWT domain and test the algorithm. Simulation results of the algorithm show that the method have strong robustness when experience attack, and we can extract clear watermark after that.