Geometric Attack Resistant Image Digital Watermarking Technology And Its Application

With the great development of Internet, the application of digital media spreads quickly. Digital media has many advantages while analog media has not. But these virtues also result in the critical problem of piracy. The traditional protecting technique can't satisfy the request of protecting authority. So in the early 1990's a new technique, digital watermarking, comes up. Because of its startling merits the academic pays more attention to it. Within a short decade, this technique has been applied into lots of aspects with its rapid development.In twenty-first century, there is a new evolution with digital watermarking of applying it into certificate's forgery detection. We follow close behind the times and choose this subject to do some research. The object is to bring out a new algorithm used in the certificate' forgery detecting system.In the first part of this paper, a review of digital watermarking technique is given and some developing orientations are rendered. Then we discuss about the forgery defending technique and design a certificate' forgery detecting system. In the next two parts two important and difficult problems in practice are discussed and one algorithm is given. We also use specific tests to testify the robustness of this algorithm. At last the conclusion of this paper and the future research orientations are pointed out.