Signal Compression

Abstract

This article is an introduction to a special issue on signal coding and compression. We begin by defining the concepts of digital coding and audiovisual signal compression. We then describe the four dimensions of coding performance: bit rate, signal quality, processing delay and complexity. We illustrate the two basic principles of audiovisual coding, removal of signal redundancy and the matching of the quantizing system to the properties of the human perceptual system, with specific recent examples of coding algorithms. We then summarize standards for, and applications of audiovisual signal compression. A fast-emerging application is the internetworking of audiovisual information, a field that is too recent to be covered in the articles in this collection. We conclude our article by presenting our views about future research directions in the field.