Studies Of Distrubuted Video Coding Algorithm Based On Joint Bit-Plane

Distributed Video Coding (DVC) is a new coding paradigm which differs from traditional video coding in that it transfers the complexity from encoder to decoder. It is based on independent encoding and joint decoding and moves the implementation of motion estimation and motion offset to the decoder side, so as to simplify the encoder. Distributed video coding technology is rather applicable to wireless terminals with limited computation capacity, memory storage and power. Therefore, it is widely applied in wireless video network, wireless surveillance systems and sensor networks.This thesis mainly studies joint bit-plane distributed video algorithm. Firstly, it introduces the basic principle of distributed video algorithms, explores the Low Density Parity Check Accumulate Codes (LDPCA) and applies it to the Distributed Video Coding system (DVC). Joint bit-plane coding algorithm uses the decoded bit-plane results as a priori and decodes the current bit-plane based on the conditional probabilities of previous results. In this way, it increases the correlation between all levels of original sequences and thus improves the decoding efficiency. Then the thesis creates a corresponding probability table for statistical models with different parameters, from which we can get the conditional probabilities for models with similar statistical characteristics. By inputting this probability to the Wyner-Ziv decoder, fast and efficient decoding is therefore achieved. This algorithm can improve the rate-distortion performance of distributed video coding without increasing the complexity of the decoding.In order to verify the performance of joint bit-plane coding algorithm, the thesis performs encoding and decoding testing on the first 200 frames of MissAm,Foreman,Carphone and Mobile sequences(QCIF,30fps). The simulation results show that the distributed video coding system based on joint bit-plane decoding algorithm greatly saves up to 20% to 30% bit rate than using an independent bit-plane coding system.