or "noiseless" source coding is data compression for applications
where the data must be represented efficiently but cannot be altered
or distorted in the compression process. Data types that typically
require lossless coding include text and computer exectuables, where
any variation in the original data string may have catastrophic consequences.
Lossless data compression is employed in a wide range of technologies,
including data storage devices, modems, and fax machines.
goal in studying lossless source coding theory is both to understand
the best performance that could conceivably be achieved in lossless
source coding and to understand how well current algorithms perform
relative to those bounds. Current work in the Data Compression Laboratory
focuses on the analysis of new and existing low-complexity universal
theoretical analyses are useful for bounding the expected performance
of a variety of lossless source codes, they do not tell the full story
about algorithms considered. Work currently under way considers the
design and implementation of practical universal lossless source codes
and the comparison of their performances on text data to the performance
of competing schemes on the same data sets.