The Research Of Video Coding Arithmetic Based On Chaos Encryption

The research of this thesis is based on the horizontal issue "Army Oil Storage Wireless Network Video Monitoring System". The Video Communication System has been developed into the third generation, which is characterized by digital network. While having more and more applications in different fields, the Video Communication System is also facing new challenges and opportunities. With the further development of network, it comes to a trend that the research of the speed and safety of the video flow. That requires higher compression ratio and more safety of the video image.The research tasks and goals of this thesis are submitted on the base of analyzing the limitation of the existing video image compression and encryption arithmetic. In this thesis, problem of the compression ratio and safety of the video image are addressed comprehensively. Considering this, a project which is to compress and encrypt the video image is brought forward. When the fractal theory is used in the image compression field, it can achieve higher compression ratio and the decompressed speed can be very quick. Firstly the fractal compression of gray image is analyzed; in succession the fractal theory development in the video compression field is studied. Based on this, self-adaptive combination arithmetic is proposed. This method is reverse to the traditional image division method. Firstly it makes the least size division, and then according to the combination error, combines these sub-blocks together. Simulation testing shows that this method can not only shorten the time of the fractal compression but also heighten the compression speed. Because of its sensitive to initial value and its good diffusibility, chaos is especially suited to the encryption system. The traditional two-dimension reversible image encryption which is based on the Cat mapping can achieve higher safe effect. But because of its short-tern predictable character, the low dimension chaos mapping has its own limitation. We extend the two-dimension Cat mapping to the three-dimension Cat mapping, and then use it to encrypt the video image which has been disposed by fractal compression. Using this, the encryption can be much safer, at the same time, the speed of encryption and decryption is heightened. The system testing shows that this project can reach the anticipative goal.A video coding arithmetic which is based on fractal compression and chaos encryption is presented in this thesis. The arithmetic can be used in wireless network video monitoring system. It can provide safety assurance for the transmission and receiving of the video image, and it is suited to the environment which calls for the safety.