This chapter provides an overview of the ISO MPEG-4 standard. The MPEG-4 work includes natural video, synthetic video, audio and systems. Both natural and synthetic video have been combined into a single part of the standard, which is referred to as MPEG-4 visual (ISO/IEC, 1998a). It should be emphasized that neither MPEG-1 nor MPEG-2 considers synthetic video (or computer graphics) and the MPEG-4 is also the first standard to consider the problem of contentbased coding. Here, we focus on the vid