In many practical distributed source coding (DSC) applications, correlation information plays several important roles at decoding, which provides the prior knowledge of the source statistics for the decoding algorithm...
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In many practical distributed source coding (DSC) applications, correlation information plays several important roles at decoding, which provides the prior knowledge of the source statistics for the decoding algorithms to start work. Therefore, the accurate utilization of such correlation information has a significant impact on decoding performance. In this work, a hybrid DSC (HYDSC) scheme is proposed to generate the "soft'' information about the clean source symbols, which allows the channel code-based DSC scheme to effectively utilize the inter/intra source correlation without requiring prior knowledge of its statistics, so as to further improve the decoding performance. Further performance improvement, at the cost of moderate increasing in computational complexity, can be achieved by performing additional iterations on the basis of the HYDSC scheme. We mainly focus on, in particular, applications where Slepian-Wolf coding and usual source coding are jointly used to exploit both the correlation among the adjoining source symbols and the correlation between the sources. Experiment results indicate that the presented scheme not only show superior performance from an error correction viewpoint, but also achieve better compression ratio in the case of strong internal correlation of the source sequence, as compared with the previous DSC techniques.
Different from traditional source coding techniques, distributed source coding (DSC) techniques rely on independent encoding at the encoding end but joint decoding at the decoding end to compress image sources which e...
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Different from traditional source coding techniques, distributed source coding (DSC) techniques rely on independent encoding at the encoding end but joint decoding at the decoding end to compress image sources which exhibit correlation. Channel code-based DSC techniques compress correlated image sources by fully utilizing such correlation. However, in addition to this correlation information, the current symbol of most real image sources is correlated to the preceding or subsequent symbols. Such correlation information should also play an important role for improving the compression performance of channel code-based DSC schemes. To this end, we present an efficient message passing mechanism for LDPC Code-based DSC schemes (ELCDSC) to compress correlated image sources. By utilizing this message passing mechanism, we enable LDPC code-based DSC techniques to not only make full use of the inter-source correlation to assist compression, but also integrate the intra-source correlation in each message passing iteration to improve the compression performance. It is the first that enables LDPC code-based DSC techniques to achieve the utilization of both intra- and inter-source correlations in the message passing mechanism. Experimental results reveal that ELCDSC significantly enhances the compression ratio of correlated image sources, surpassing other DSC schemes.
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