LOSSY SOURCE-CODING

Lossy coding of speech, high-quality audio, still images, and video is commonplace today. However, in 1948, few lossy compression systems we re in service. Shannon introduced and developed the theory of source c oding with a fidelity criterion, also called rate-distortion theory. F or the first 25 gears of its existence, rate-distortion theory had rel atively little impact on the methods and systems actually used to comp ress real sources. Today, however, rate-distortion theoretic concepts are an important component of many lossy compression techniques and st andards, me chronicle the development of rate-distortion theory and pr ovide an overview of its influence on the practice of lossy source cod ing.