Uniform trellis coded quantization for image transmission over noisy channels

A combined source/channel coding scheme without explicit error protection is proposed to transmit images through binary noisy channels. Unlike the error protection with re-transmission scheme and error concealment scheme by inserting synchronization codewords to entropy-coded bitstream, the proposed...

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Vydáno v:Signal processing. Image communication Ročník 14; číslo 6; s. 575 - 584
Hlavní autoři: Chen, Chang Wen, Sun, Zhaohui
Médium: Journal Article
Jazyk:angličtina
Vydáno: Elsevier B.V 1999
Témata:
Error-resilient image coding
Fixed length coding
Image compression
Noisy channel
Optimal bit allocation
Trellis coded quantization
Trellis coded quantization
Image compression
Error-resilient image coding
Optimal bit allocation
Fixed length coding
Noisy channel
ISSN:0923-5965, 1879-2677
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Shrnutí:A combined source/channel coding scheme without explicit error protection is proposed to transmit images through binary noisy channels. Unlike the error protection with re-transmission scheme and error concealment scheme by inserting synchronization codewords to entropy-coded bitstream, the proposed coding scheme employs transform coding, fixed-rate uniform threshold trellis coded quantization (UTTCQ) and optimal bit allocation algorithm (BAA) to organize the bitstream in a way that is less sensitive to channel noise, achieving data compression and error resilience at the same time. An image is first block transformed to the frequency domain and the same frequency components in different blocks are grouped together as a single subsource. Every subsource is then quantized by a uniform threshold trellis coded quantizer constructed based on the mean and variance of the subsource. Steepest descent method and iterative scheme are employed to determine the optimum bit allocation among the subsources subject to the constraints of the average coding rate and allowable bits to each sample. The coding system uses no error protection, no synchronization codewords and no entropy coding. However, it shows decent compression ratio and gracious degradation with respect to increasing channel errors.
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ISSN:0923-5965
1879-2677
DOI:10.1016/S0923-5965(98)00065-4