Based On Spread Spectrum, Interleaving And Jpeg Compression Of Digital Image Watermarking Technology

With the fast development of computer and multi-media techniques, all kinds of digital multi-media products can be found in our life. Meanwhile, the convenient and fast network communication technique makes us get all kinds of information on the net freely. Thus the problems of information transportation safety and the protection of digital product copyright come out. But the conventional encryption and digital idiograph techniques can not solve these two problems well, and after the digital product is dealt with these two techniques, it can not be used in a normal way. At the same time, it is easy to be unencrypted and delete the digital idiograph. In this condition, the digital watermarking can solve this effectively, for there is no effect for the digital product embedded with the watermarking information to be used normally. And it is not easy to erase the watermarking information with normal process.The thesis mainly researches the digital watermarking of color picture in JPEG. and realize it with real software program, including the attacking experiments for robustness. In the period of researching this theme, firstly, the general condition and basic theory of watermarking are summed up by consulting lots of documents, including analyzing the existing typical watermarking algorithms. After that, in the real design, by analyzing the characteristics of color picture and the specialty of energy distributing after DCT transformation and quantitative division, the watermarking embedded areas can be confirmed. At the same time, by a lot of experiments can be decided the number of embedded information. Meanwhile, in order to make the watermarking system fight back the attack better and transport on the net conveniently, linking with the process and specialty of watermarking production and referring to the existing watermarking algorithms in JPEG, one new kind of digital watermarking algorithm in the JPEG is brought forward. This algorithm is that the watermarking is multi-embedded in the JPEG and is distributed in the full original picture by using the technique of spread spectrum,parity check code and interlacement after being dealt with gray scale and two-value process. In addition, when the picture embedded with watermarking is attacked balefully, watermarking can be gotten as much as possible for using these techniques. The experimental results show that the proposed algorithm has good robustness and invisibility.Finally, the thesis is summarized detailedly and earnestly in all together, with some possible research and being ameliorated in more degree in the future.