Joint Source and Channel Coding for Image Transmission Over Lossy Packet Networks

We describe a joint source/channel allocation scheme for transmitting images lossily over block erasure channels such as the Internet. The goal is to reduce image transmission latency. Our subband-level and bitplane-level optimization procedures give rise to an embedded channel coding strategy. Source and channel coding bits are allocated in order to minimize an expected distortion measure. More perceptually important, low frequency channels of images are shielded heavily using channel codes; higher frequencies are shielded lightly. The result is a more efficient use of channel codes that can reduce channel coding overhead. This reduction is most pronounced on bursty channels for which the uniform application of channel codes is expensive. We derive optimal source/channel coding tradeoffs for our block erasure channel.