The Research Of Digital Watermarking System And Robust Digital Watermark Of Still Image

The digitalization of the multimedia data provides much convenience for the multimedia information's storage and extraction. It makes much improvement of the efficiency and veracity of information expression. With the development of the IC technology and the Internet, multimedia communication has improved to an unprecedented situation. People can distribute their writing and make trades through Internet. This brings a serious private problem.Up to now, Encryption cannot solve this problem entirely. Encryption can only protect the data in the transmitting process. The digital watennarking technique has been thought the efficiency tool of the copyright protection.In the first part of this thesis, the basic knowledge for digital watermarking in image processing, the traditional information security techniques and the information hiding techniques are introduced. Then constructs a frame of the digital watermarking system and discusses the digital watermarking background, definition, mathematical model, general properties and requires, classification, algorithm, attacks and assess on digital watermarking and present studies in digital watermarking. Finally, proposes a new watermarking algorithm based on digital holography and JPEG model to the gray-level image; then on its basis, a new adaptive color image watermarking scheme based on three components embedding and extracting is proposed furthermore. The simulation results show a higher performance in transparency and robustness.This thesis shows the originality in constructing the frame of the digital watermarking system theory and proposing the new digital watermarking algorithms on gray-level image and color image.