We establish a random variable substitution lemma and use it to
investigate the role of refinement layer in multiple description coding,
which clarifies the relationship among several existing achievable
multiple description rate-distortion regions. Specifically, it is shown
that the El Gamal-Cover (EGC) region is equivalent to the EGC* region
(an antecedent version of the EGC region) while the
Venkataramani-Kramer-Goyal (VKG) region (when specialized to the
2-description case) is equivalent to the Zhang-Berger (ZB) region.
Moreover, we prove that for multiple description coding with individual
and hierarchical distortion constraints, the number of layers in the VKG
scheme can be significantly reduced when only certain weighted sum rates
are concerned. The role of refinement layer in scalable coding (a
special case of multiple description coding) is also studied.
|State||Published - 1 Sep 2009|
- Computer Science - Information Theory