Progressive transmission of images over memoryless noisy channels

摘要

An embedded source code allows the decoder to reconstruct thensource progressively from the prefixes of a single bit stream. It isndesirable to design joint source-channel coding schemes which retain thencapability of progressive reconstruction in the presence of channelnnoise or packet loss. Here, we address the problem of jointnsource-channel coding of images for progressive transmission overnmemoryless bit error or packet erasure channels. We develop a frameworknfor encoding based on embedded source codes and embedded errorncorrecting and error detecting channel codes. For a target transmissionnrate, we provide solutions and an algorithm for the design of optimalnunequal error/erasure protection. Three performance measures arenconsidered: the average distortion, the average peak signal-to-noisenratio, and the average useful source coding rate. Under the assumptionnof rate compatibility of the underlying channel codes, we providennecessary conditions for progressive transmission of jointnsource-channel codes. We also show that the unequal error/erasurenprotection policies that maximize the average useful source coding ratenallow progressive transmission with optimal unequal protection at annumber of intermediate rates