LTS4, Swiss Federal Institute of Technology (EPFL), Signal Processing Institute, Lausanne 1015, Switzerland
Copyright © 2007 Ivana Radulovic and Pascal Frossard. This is an open access article distributed under the
Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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.