The images shown here are good examples of how intelligent source
coding can pay off. The first image uses conventional image coding techniques designed for
data channels that exhibit a random distribution of bit errors with time. When subject to
a channel that produces short, focused bursts of errors, the decoded image is severely
degraded. The second image has been passed through an encoder/decoder designed to be
resilient to burst errors, and clearly demonstrates the marked improvement that can be
achieved if the source coding is tailored to the channel error conditions - where known.
(Images kindly provided by Professor David Bull, Centre for Communications Research,
University of Bristol.)
|