Research On Watermarking Method Using Wavelet Transform

Along with the development and extensively application of the computer and internet, the traditional publication and the dissemination method will take place a very big change. However replication, distort, the pirate edition and illegal dissemination on internet threaten the copyright of the author. Watermark become a new copyright protection method, the research of this aspect is more and more.First, Introduce the need background of the numerical watermark and the present condition of the domestic and international research, make a summary of the concept, characteristic, classification of watermark.Secondly, implement a spatial domain LSB algorithm. LSB algorithm is one of classic spatial domain algorithm.Then, introduced DCT domain algorithm, an adaptive image watermarking algorithm in DCT domain based on the block classification is proposedIn succession, introduced the theory of wavelet transform, and summarized a human visual model which applies in watermark algorithm.Finally, analyzed a watermark algorithm based on wavelet, and improved it with the human visual model. The watermark is a meaningful binary image. We selected the wavelet coefficients based on HVS, and then the coefficients were modified to embed the watermark. It was shown with experiments that not only get the better transparency, but also has good robustness to JPEG compression, additive noise and filter etc. Because the colorful picture has to be in the predominant position, so continued to carry on an improvement to the algorithm, implement a watermark algorithm based on color picture.