Key Technologies Of The Distributed Video Coding

The traditional video compression technologies (such as H.26x, etc.)mainly implement complicated transformation, prediction and entropy coding at the encoder to achieve the purpose of information compression, which leads a complex encoding process and needs an encoder with a high complexity. However, with the development of the low-cost video sensor network and mobile multimedia, the traditional video coding can not meet the need of the new situation. So, the Distributed Video Coding (DVC) scheme is becoming more and more attractive.This coding scheme makes the complexity calculation on the decoder side to reduce the complexity of the encoder.Based on the Turbo codes DVC,the main works done in the paper are as follows:1.The Turbo encoding and decoding theory are expatiated. And we mainly study the Maximum A Posteriori decoding algorithm to make it more suitable to implement the decoder of DVC.Turbo encoder is used as the encoder of DVC with the difference of using request scheme based on the puncturing matrix when the decoding fails.The simulation results show that the proposed scheme has better performance than the traditional intra prediction coding scheme (H263+),but with some gap with the inter prediction coding scheme (bidirectional).2.Side information generation algorithm,such as extrapolation and interpolation, is studied.Under the framework of DVC,interpolation algorithm is used to generate the side information. Average interpolation and motion compensation interpolation based on block matching are studied. We analyze both the advantages and disadvantages of the two methods, and then, a combined algorithm is proposed. The simulation results show that the proposed scheme makes a better performance than anyone of the two methods.3.Virtual channel model in DVC is also studied in the paper, we proposed a new parameter estimation scheme, experimental result shows that the proposed scheme makes a better performance than that of using one parameter in the whole video sequence in the condition of high bit quantization.