Study On Robust Digital Watermarking Algorithm Based On Chaos

With the fast development of online communication and network, multimedia has became an important way of getting information, and also it has been an important part of our daily life. We get convenient in the development, but in the meantime, a big problem has come out that is the security of the data on the internet. Especially for the problem of copyright protection of Digital products, and the problem has been paid more and more attention these years. The traditional encryption theory can only protect those encrypted digital data. After the data is decrypted, it can be copied and transmitted without any limitation, thus the copyright can not be protected effectively. Watermark technique is just out for this problem. Nowadays, watermark technique is taken as an significant way of copyright protection and is being widely researched and applied.Aim at image processing especially the digital watermark technology, the dissertation does a good research on the good properties of chaotic system. Below is the main work:①We introduce the researching background and development of watermark technology and it's application. And some typical algorithm were given, and also the requirement of robust watermark algorithm.②We make a comprehensive introduction to the concept, characteristics and application in image processing of chaotic system. Put out some ways of chaotic sequence used in digital watermark technology. Introduce wavelet and it's application in image decomposition.③Based on the technology of chaos and wavelet, a schema combined compression and encryption of image processing is proposed. And the advantages of encryption with chaos and compression with wavelet were given under the simulation.④Focusing on the Logistic chaotic system, analysis and discussion of it's characteristics are given. Introduce SVD and based on Logistic sequence, we design a new robust watermark algorithm in order to solving the problem of copyright protection. Using different ways and different embedding positions, on the premise of good transparency, the algorithm behaves very robust.At the end of the dissertation, the innovative points and some problems needs to be further studied are given.