Source Coding With Encoder Side Information

Abstract

We introduce the idea of distortion side information, which does not directly depend on the source but instead affects the distortion measure. We show that such distortion side information is not only useful at the encoder, but that under certain conditions, knowing it at only the encoder is as good as knowing it at both encoder and decoder, and knowing it at only the decoder is useless. Thus distortion side information is a natural complement to the signal side information studied by Wyner and Ziv, which depends on the source but does not involve the distortion measure. Furthermore, when both types of side information are present, we characterize the penalty for deviating from the configuration of encoder-only distortion side information and decoder-only signal side information, which in many cases is as good as full side information knowledge.