Research On Adaptive Color Image Watermarking Based On DCT

The digitalization of the multimedia data provides much convenience for the multimedia information's storage and extraction.lt makes much improvement of the efficiency and veracity of information expression.Each data can be distributed freely in Internet,but pirate problem follows this.Traditional Encryption technique cannot solve copyright protection problem entirely,which encrypts data only in transporting process,not only limiting people's use but also having low level security. Digital watermarking technique is an efficiency tool of copyright protection.Being compared with Encryption,it overcomes the shortcomings of Encryption technique in multimedia copyright protection,and provides the complementary solution for Encryption technique.The digital watermarking technique on color image is studied in this paper. We analysis the features of color image,choose the area in which watermarking is to be embedded,improve the classify of image blocks on HVS. Then propose an adaptive color image watermarking algorithm based on DCT, which adaptive adjusts embedding threshold using the feature of HVS and ratio of RGB in 8 X 8 block,and embed watermarking in RGB channels. The experimental results show that the proposed algorithm has good robustness and invisibility.Finally,the thesis is concluded,together with some possible research directions in the future.