In Wyner-Ziv (WZ) Distributed Video Coding (DVC), correlation noise model is often used to describe the error distribution between WZ frame and the side information. The accuracy of the model can influence the perform...In Wyner-Ziv (WZ) Distributed Video Coding (DVC), correlation noise model is often used to describe the error distribution between WZ frame and the side information. The accuracy of the model can influence the performance of the video coder directly. A mixture correlation noise model in Discrete Cosine Transform (DCT) domain for WZ video coding is established in this paper. Different correlation noise estimation method is used for direct current and alternating current coefficients. Parameter estimation method based on expectation maximization algorithm is used to estimate the Laplace distribution center of direct current frequency band and Mixture Laplace-Uniform Distribution Model (MLUDM) is established for alternating current coefficients. Experimental results suggest that the proposed mixture correlation noise model can describe the heavy tail and sudden change of the noise accurately at high rate and make significant improvement on the coding efficiency compared with the noise model presented by DIStributed COding for Video sERvices (DISCOVER).展开更多
We address the compression efficiency of feedback-free and hash-check distributed video coding,which generates and transmits a hash code of a source information sequence.The hash code helps the decoder perform a motio...We address the compression efficiency of feedback-free and hash-check distributed video coding,which generates and transmits a hash code of a source information sequence.The hash code helps the decoder perform a motion search.A hash collision is a special case in which the hash codes of wrongly reconstructed information sequences occasionally match the hash code of the source information sequence.This deteriorates the quality of the decoded image greatly.In this paper,the statistics of hash collision are analyzed to help the codec select the optimal trade-off between the probability of hash collision and the length of the hash code,according to the principle of rate-distortion optimization.Furthermore,two novel algorithms are proposed:(1) the nonzero prefix of coefficients (NPC),which indicates the count of nonzero coefficients of each block for the second algorithm,and also saves 8.4% bitrate independently;(2) the adaptive selection of hash functions (AHF),which is based on the NPC and saves a further 2%-6% bitrate on average.The detailed optimization of the parameters of AHF is also presented.展开更多
基金Supported by the National Natural Science Foundation of China (No. 61071091)Jiangsu Province Graduate Innovative Research Plan (CX07B_107Z)
文摘In Wyner-Ziv (WZ) Distributed Video Coding (DVC), correlation noise model is often used to describe the error distribution between WZ frame and the side information. The accuracy of the model can influence the performance of the video coder directly. A mixture correlation noise model in Discrete Cosine Transform (DCT) domain for WZ video coding is established in this paper. Different correlation noise estimation method is used for direct current and alternating current coefficients. Parameter estimation method based on expectation maximization algorithm is used to estimate the Laplace distribution center of direct current frequency band and Mixture Laplace-Uniform Distribution Model (MLUDM) is established for alternating current coefficients. Experimental results suggest that the proposed mixture correlation noise model can describe the heavy tail and sudden change of the noise accurately at high rate and make significant improvement on the coding efficiency compared with the noise model presented by DIStributed COding for Video sERvices (DISCOVER).
基金supported by the National Basic Research Program (973) of China (No.2009CB320903)the Program for New Century Ex-cellent Talents in University,China
文摘We address the compression efficiency of feedback-free and hash-check distributed video coding,which generates and transmits a hash code of a source information sequence.The hash code helps the decoder perform a motion search.A hash collision is a special case in which the hash codes of wrongly reconstructed information sequences occasionally match the hash code of the source information sequence.This deteriorates the quality of the decoded image greatly.In this paper,the statistics of hash collision are analyzed to help the codec select the optimal trade-off between the probability of hash collision and the length of the hash code,according to the principle of rate-distortion optimization.Furthermore,two novel algorithms are proposed:(1) the nonzero prefix of coefficients (NPC),which indicates the count of nonzero coefficients of each block for the second algorithm,and also saves 8.4% bitrate independently;(2) the adaptive selection of hash functions (AHF),which is based on the NPC and saves a further 2%-6% bitrate on average.The detailed optimization of the parameters of AHF is also presented.
