Joint source and channel coding/decoding by concatenating an oversampled filter bank code and a redundant entropy code [image coding application]
This paper examines a joint source and channel coding (JSCC) technique based on oversampled filter banks (OFB). We consider an image compression system with an OFB based signal decomposition followed by scalar quantization and a redundant entropy coding scheme. This encoding chain can be viewed as a concatenation of an OFB code and an error correcting entropy code. The error correcting ability of an OFB comes from the explicit redundancy introduced into the transmitted signal by oversampling while the error correcting ability of the entropy code comes from the implicit redundancy due to the Markov property of the OFB outputs. The decoder consists of the soft-input soft-output entropy decoder and a syndrome decoder for the OFB code. The soft information at the output of the entropy decoder is utilized in the error localization procedure of the OFB syndrome decoder. The performance of the algorithm is examined for an image coding system with a wavelet filter bank.