MPEG-7 visual motion descriptors

This paper describes tools and techniques for representing motion informati on in the context of MPEG-7 standardization for multimedia description inte rfaces. It first gives an overview of the current organization of the see o f MPEG-7 motion descriptions, then illustrates this by presenting two of th em, motion activity and motion trajectory, in more detail,It explains how t o extract them fi om the content, how to express them in a compact way, and illustrates their use in concrete applications scenarios.