traditional (single-resolution) source codes, multi-resolution source
codes are data dependent. The optimal multi-resolution source code
for a particular source guarantees good coding performance on that
source, but may achieve poor performance on other sources. In
the interest of designing source-independent multi-resolution source
codes to achieve good performance across a broad class of possible
sources, we have recently introduced the new field of universal multi-resolution
goal in universal multi-resolution source coding is to design a single
code that will -- in the long run -- do as well on each source in
some class of sources as if it were designed for the source in operation,
and to do so without prior knowledge of the source to be compressed.
At first glance, universal multi-resolution source codes, like universal
(single-resolution) source codes seem too good to be true. Yet early
work in this nascent field has included not only proofs of the existence
of these codes but also given bounds on their performance.
universal multi-resolution source coding theory proves the existence
of universal multi-resolution source codes, the proofs are not constructive.
That is, the proofs demonstrate the existence of good codes without
describing how to find those codes in practice. Recent work in practical
universal multi-resolution source coding treats the problem of optimal
universal multi-resolution source code design. This work takes an
approach similar to that used in the weighted universal vector quantization
algorithm, but generalizes that approach by building a collection
of multi-resolution source codes rather than a collection of single-resolution
source codes and by allowing the first-stage source description itself
to be multi-resolution in nature.