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Soft decoding and synchronization of arithmetic codes: application to image transmission over noisy channels
Thomas Guionnet1, Christine Guillemot
1Projet TEMICS, IRISA-INRIA Campus de Beaulieu, 35042 Rennes Cedex, France. thomas.guionnet@irisa.fr
Summary
This study introduces a robust soft decoding algorithm for arithmetic codes, enhancing error resilience in data transmission. The method improves synchronization and is effective for practical systems like JPEG-2000 image compression.
Area of Science:
- Information Theory
- Digital Communications
- Computer Vision
Background:
- Arithmetic coding is crucial for data compression.
- Robust source-channel decoding is essential for reliable data transmission.
- Existing methods may lack sufficient error resilience.
Purpose of the Study:
- To develop a robust and joint source-channel decoding method for arithmetic codes.
- To design a soft decoding algorithm with high error resilience.
- To apply and evaluate the algorithm in practical systems like JPEG-2000.
Main Methods:
- Bayesian formalism to analyze variable dependencies in arithmetic coding.
- Development of a soft decoding algorithm incorporating soft synchronization.
- Implementation of an efficient pruning method to manage computational complexity.
- Integration into an iterative source-channel decoding framework.
Main Results:
- The proposed soft decoding algorithm demonstrates high error resilience.
- Soft synchronization anchors improve the likelihood of synchronized decoding paths.
- The pruning method keeps estimation complexity within realistic bounds.
- Experimental results show very good error resilience for theoretical sources and JPEG-2000 coded images.
Conclusions:
- The developed Bayesian-based soft decoding approach offers significant improvements in error resilience for arithmetic codes.
- The algorithm is well-suited for practical applications, including image compression standards like JPEG-2000.
- The iterative structure and soft synchronization contribute to robust joint source-channel decoding.
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