Research Of Digital Watermarking Algorithm And Detection System

With the rapid development of computer communications technology and Internet,images, audio, video and other forms of digital multimedia works are spread more and more convenient and efficient. But, as the digital works information can easily be altered, copied, it led great economic losses to the original writer. Copyright protection of digital works has becoming an urgent problem need to be resolved. Compared with traditional forgery prevention techniques, the present techniques have the advantage of low-cost and easily operated. It is significant to introduce digital watermark technique in the presswork forgery prevention field.Based on digital watermarking Theory, this paper carries out research on how to improve the application of robustness watermarking and reversible watermarking in Solidworks ,and design a robustness software which can detection suspicious' images. The main contents are as follows:First of all, propose a strategy to improve the watermark robustness. Based on spatial and frequency transform, three methods are proposed to improve the robustness of watermarking:decrease image spectrum energy, magnify watermarking noise and transfer watermarking information. The Digimarc digital watermarking plug-ins of Photoshop can be used as an example, these methods can improve the robustness when Digimarc's principle is unknown.Secondly, apply reversible image watermarking technology to the Solidworks. With the rapid development of Internet and CAD technology, and the competition of global component procurement market and manufacturing enterprise, CAD models growth fast. How to protect the copyright of CAD model is becoming a real problem to be solved urgently. Based on the small degree of data redundancy, and high-precision in Solidworks 3D model diagram,. Theoretical analysis and experimental results show that the algorithm is a very good way to solve the conflict between robustness and invisibility in watermark, and realize blind extraction, and also the original engineering drawing can be fully restored.Finally, establish a common image watermark detection system based on C + + and Matlab Hybrid Programming. Digital watermarking technology is a double-edged sword, it can be used to protected image copyright, also can be used to communicated secretly by criminals. In order to monitor and manage the image of national by security sector, we have to research on the opposite direction of digital watermarking technology--watermark detection and analysis techniques. Experimental results show that the system has rapid speed and high accuracy in detecting BMP, JPG, TIFF. The software has been adopted by Zhejiang Safety Agency at present.