DCT Image Digital Watermarking Algorithm Based On Human Visual System

With the increasing popularization of the internet, the information exchange of multimedia has reached an unprecedented level. The network has become the main way to publish and disseminate the digital works. With the rapid development of network information technology, we are stepping into the digital era, and facing unprecedented challenge. The phenomena of piracy prevail increasingly, and the traditional measures of intellectual property protection can not solve the current problems of intellectual property protection of digital works. The digital watermarking technology emerges as the times require. It embeds a copyright information into multimedia products by digital watermarking algorithm, authenticates the ownership and transmits the available information.On the basis of previous studies, targeting at the present situation of digital watermarking, the dissertation probes into DCT image digital watermarking algorithm based on human visual system. The main innovative work is as follows:Firstly, the background information about the emergence and development of the digital watermarking technology is reviewed, and the present situation, the existing problems and the development trend of digital watermarking technology study are analyzed.Secondly, the thesis takes image digital watermarking algorithm as the research object, mainly focusing on transparent watermarking which is used in copyright protection. Robustness and invisibility are contradictory elements in digital watermarking technology. Transparent watermarking for copyright protection need to improve the robustness and guarantee the invisibility at the same time. The thesis puts forward a solution to the problem from the perspective of embedding strategy.Thirdly, the thesis adopts the research method of combining the experiment and the theory analysis, studies on the problem of balancing the robustness and the invisibility, puts forward DCT image digital watermarking algorithm based on human visual system, and makes a simulation verification with Matlab7.0.