Adaptive Watermark Algorithm Based On HVS And CIRC

With the rapid development of computer, multimedia and Internet techniques, it is very easy to illegally reproduce multimedia data and spread them. Therefore, it is urgent to protect the intellectual property rights of multimedia data. Currently, watermarking algorithm is the most effective way to protect the ownership of multimedia data. It is crucial to develop effective watermarking watermarking techniques.In this dissertation, a systematical applications and algorithm of watermarking techniques is studied. This paper takes still images as example. The main contributions of this dissertation can be summarized as follows:1. An adaptive watermark algorithm based on HVS and SVR is proposed in this paper. The larger the watermark is, the stronger the robustness of the watermark could be. Therefore, the robustness of the watermark can be enhanced by increasing each watermark strength. In order to increase every watermark strength, simultaneously keep the watermark imperceptible, the HVS is used in concluding the watermark strength. The HVS is very difficult to be described. SVR is adopted to model the HVS to determine the adaptive watermark strength by considering the image features which affect the visibility of the watermark. This algorithm constructs important wavelet coefficient according to the EZW theory, and then the watermark are embedded into the important wavelet coefficient. 2. Some operations or attacks can degrade the watermarked images, so some extracted watermark can be error. Through researching the error check and error correction algorithm, a watermark algorithm based on CRC and CIRS is proposed. In this algorithm, the CRC is adopted to check the extracted watermark and CIRC adopted to correct the error extracted watermark. Extensive experiments show that the algorithm possesses significant robustness against the various attacks.