Iterative decoding of JPEG coded images with channel coding
Wei Xiang, Steven S. Pietrobon, S.A. Barbulescu · 2003
The iterative decoding of JPEG coded images combined with channel coding over noisy channels is investigated. JPEG images use the Huffman codes as the variable length coding scheme. These Huffman codes can be represented by an irregular trellis structure proposed by Balakirsky (1997). State transition probabilities can be derived from the irregular trellis and can be used as a priori information to help iterative decoding between channel and source APP decoders. Due to the poor distance property of original JPEG DC Huffman code, a symmetric RVLC with free distance d/sub f/ = 2 is proposed, which can dramatically improve the system performance when iterative decoding is performed.