| With the development of multimedia information and Internet, more and more multimedia data are widely distributed in digital form, which provides great convenience for the information storage and access. The problems of digital media security, such as copyright protection and authentication, have become more serious. A new technology, digital watermarking, which embed some data in the multimedia, has become a research hot-spot in recent years. In this thesis, based on the overview of digital watermarking, we mainly study on the Digital Integrated Watermarking, a technology for image authentication.The mainly contributions of the paper as fellows:1) According to the differences applications of the digital watermarking, we firstly divided it into two categories: Digital Marked Watermarking (DMW) and Digital Integrated Watermarking (DIW). This classification is useful for us to understand the meaning of digital watermarking, the principles of digital watermarking algorithm and the relations between watermarking components.2) After analyzing the principle and algorithms of Digital Marked Watermarking, we state the tough question of this area.3) Some novel Digital Integrated Watermarking methods based on SVD are proposed. In order to enhance the ability of tolerance JPEG compression, we present SVD in DCT and DWT domains. Experimental results show that the new watermarking methods perform well in JPEG compression.4) Two schemes are presented to raise the security of SARI algorithm in Digital Integrated Watermarking. SARI algorithm is the JPEG compression tolerant multimedia content authentication technique, which was proposed by LIN and Chang et al in 2001. Its security is depended on the grouping function and the threshold. The cost of eliminating the watermark is small because of its linear function and the single threshold. Theories and experimental results show its weaknesses. Two novel methods are proposed to enhance the system security by using encryption and coding techniques. |
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