Multiple Description Coding with Redundant Expansions and Application to Image Communications

Ivana Radulovic,Pascal Frossard

doi:10.1155/2007/24863

Abstract

Multiple description coding offers an elegant and competitive solution for data transmission over lossy packet-based networks, with a graceful degradation in quality as losses increase. In the same time, coding techniques based on redundant transforms give a very promising alternative for the generation of multiple descriptions, mainly due to redundancy inherently given by a transform, which offers intrinsic resiliency in case of loss. In this paper, we show how partitioning of a generic redundant dictionary can be used to obtain an arbitrary number of multiple complementary, yet correlated, descriptions. The most significant terms in the signal representation are drawn from the partitions that better approximate the signal, and split to different descriptions, while the less important ones are alternatively distributed between the descriptions. As compared to state-of-the-art solutions, such a strategy allows for a better central distortion since atoms in different descriptions are not identical; in the same time, it does not penalize the side distortions significantly since atoms from the same partition are likely to be highly correlated. The proposed scheme is applied to the multiple description coding of digital images, and simulation results show increased performances compared to state-of-the-art schemes, both in terms of distortions and robustness to loss rate variations.

Highlights

Efficient transmission of information over erasure channels has attracted a lot of efforts over the years, from different research communities
We analyze in more details the performance of our scheme in the case where the number of descriptions is limited to 2 and, respectively, 3 descriptions. We compare these performances to two multiple description coding (MDC) schemes that implement simple atom repetition [17], and unequal error protection (UEP) [31]
This paper has presented a multiple description coding scheme, which exploits the redundancy present in redundant

Summary

Introduction

Efficient transmission of information over erasure channels has attracted a lot of efforts over the years, from different research communities. Since multiple description coding offers several advantages, such as interesting graceful degradation in the presence of loss, and a certain robustness to uncertainty about channel characteristics, it has motivated the developments of numerous interesting coding algorithms. Some of these approaches completely rely on the redundancy present in the source, while others try to introduce a controlled amount of redundancy such that the distortion after reconstruction gracefully degrades in the presence of loss. The main challenge remains to limit the increase of rate compared to a single description case, and to trade off side and central distortions depending on the channel characteristics

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Results

Conclusion