We present a new embedded zerotree wavelet image coding algorithm that
is based on the algorithms developed by Shapiro and Said ct al, Our a
lgorithm features a relatively simple coding structure and provides a
better framework for balancing between high compression performance an
d robustness to channel errors, The fundamental approach is to explici
tly classify the encoder's output bit sequence into subsequences, whic
h are then protected differently according to their importance and rob
ustness, Experimental results indicate that, for noisy channels, the p
roposed algorithm is slightly more resilient to channel errors than mo
re complex and sophisticated source-channel coding algorithms, More im
portant is that our algorithm is substantially more robust with respec
t to varying channel error conditions, This provides much needed relia
bility in low-bandwidth wireless applications.