Research And Application Of Digital Watermark Algorithm Based On Image Encryption And SVD

With the rapid development of computer and network technology, digital multimedia information resources are widely used in people's work and life. Computer formidable information-handling capacity provides the enormous convenience for the multimedia information's deposits. At the same time, the information copyright protection and series of related questions also become a hot topic. As a new copyright protection means of digital products, digital watermark is the important branch in the international information hiding domain.The basic method of digital watermark is the copyright owner inserts own copyright information into the product, the inserting information is literal showing, special indication or image form. When the product is found has been infringed in the spreading process, the copyright owner depends upon the extraction inserting information to prove that he has the copyright. Thus protect copyright or integrity of digital works. The digital watermark technology is an emerging multi-disciplinary cross-application technology, involves the different discipline theory and the technology, such as signal processing, image processing, and information theory, coding theory, cryptography, detection theory, and digital communications and networking technology and so on. Watermark technology development also led to the further development of related fields. Therefore, regardless of from theory angle or application angle, development digital watermark technology research, not only has the vital academic significance, but also has the great importance practical value. The digital watermark already involved the image watermark, video watermark, audio watermark, text watermark and three-dimensional grid data watermark and so on. Most of the watermark research and thesis research has focused on the image research.This article mainly researched the image digital watermark algorithm, and encrypted the watermark images. Then combined with HVS, a method of digital watermark algorithm is proposed based on discrete cosine transform and singular value decomposition. This algorithm synthesized the robustness of DCT transformation territory algorithm and the image's singular value. The experimental result confirms this algorithm to have the very good robustness and invisibility. The main research work includes:First, this article summarizes the background, development and application of the digital watermark technology and introduced its basic feather, classification, characteristics, watermark attacking methods and system evaluation.Second, some typical image scrambling algorithms are described and with the comparison of these algorithms, an image scrambling method based on Logistic map is proposed, proved to be simple and easy to implement by experiments. This algorithm is difficult to crack because it is the combination of the two methods of scrambling.Third, this article introduces the basic principle of singular value decomposition and analyzes the performance of matrix singular value of the image. Then, combined with the robustness of the DCT transform domain algorithm and singular values of image matrix, a watermark algorithm based on DCT and SVD is proposed in order to improve its anti-crack ability. In order to compare with the traditional DCT transform domain watermarking algorithm, a lot of experiments are carried out, and the results show that the algorithm proposed in this article has better robustness.Fourth, the technologies for mixed programming of Matlab and VC++ are introduced and then an application of watermarking algorithm is implemented.Finally, this article summarizes the entire work, and makes a forecast of present work and the development direction of digital watermark.