Research Of Digital Image Watermarking Algorithm In Wavelet Domain Incorporated Fractal

With the rapid development of information technology and networks, it is convenient for people to spread and trade digital products such as multi-media. But the issues of digital products'copyright have aroused people's attention. It has become an urgent problem that how to protect the copyright of digital products and information security. Digital watermarking is an effective technology which can be used to protect digital products'copyright and information security under the open network environment. It has become a hot point in digital watermarking that wavelet analysis incorporated others theories such as chaos and fractal.In this paper, we firstly introduce the research on digital watermarking at present and basic concepts of digital watermarking. We study others algorithms, introduce chaos and propose an improved digital watermarking algorithm which based on compound encryption in wavelet domain. We encrypt the binary watermark image by Arnold scrambling and produce a pseudo-random sequence using Logistic map, then XOR operation the encrypted watermark with pseudo-random sequence to scrambling watermark image again. We embed the encrypted watermark in the low frequency sub-band in wavelet domain. The embedding strength can be adjusted according to the results of experiment. The results of experiment are analyzed and evaluated by the invisibility and robustness of watermark algorithm. It shows that the watermark algorithm has a good performance. We introduce fractal and propose an improved digital watermarking incorporated fractal in wavelet domain. We take good use of the relation among the coefficients of different sub-bands and different directions to construct the wavelet tree and find the best match tree in the same direction and different sub-bands to embed the watermark. Finally, the results of experiment show that the algorithm has a good invisibility and robustness. Finally we review entire work. It is pointed out that something need to research in the next step.