A Wavelet-packets Watermarking Algorithm Based On Chaos Theory

With the rapid development of multi-media technology and the coverage extension of PC network, it'll be quite convenient for us to do fast transfer of the multi-media information such as text file, image and video etc. via network. Meanwhile, the copyright protection of multi-media has become more and more obvious during the network transfer. Digital image has the features of strong correlation, large information and high redundancy. So digital watermarking has become a good way of copyright protection of the image during network transfer.The digital watermarking is a hidden technology and particular remark information which is embedded in the carrier information for protection. This technology is used to protect the integrity of digital information and copyright etc. Wavelet transform has the features of symmetry, smoothness and orthogonality during image information processing. Chaos theory has the features of sensitivity and unpredictability to the initial condition. It'll greatly improve the safety of hidden information and robustness of carrier information if the digital watermarking is combined together with wavelet transform and chaos theory. The main task of this essay is as follows:In this essay, we've mentioned a new type of digital watermarking: wavelet packets based on encrypted chaos theory. The new calculation method has taken the grey image in binary as the watermarking carrier information. It has applied the theory analysis, calculation design and realistic simulation via experiment and also combined with the digital watermarking, wavelet transform and chaos theory to design non-blind binary grey image watermarking based on encrypted chaos theory. The basic idea of calculation is as follows: 1st step is to implement encrypted chaos to the original watermarking image via Logistic mapping so as to guarantee the safety of watermarking information; 2nd step is to dissemble the carrier image into three levels of wavelet packets and divide it to be 64pieces; last step is to embed the encrypted watermarking information to the 1st, 2nd, 3rd and 9th of the dissembled carrier image so as to produce the digital image with watermarking. The extract of digital watermarking is the inverse algorithm of watermarking embedded method. It has proved that the calculation has good performance through plenty of simulation experiment.