MPEG-7 visual motion descriptors

This paper describes tools and techniques for representing motion information in the context of MPEG-7 standardization for multimedia description interfaces. It first gives an overview of the current organization of the set of MPEG-7 motion descriptions, then illustrates this by presenting two of them, motion activity and motion trajectory, in more detail. It explains how to extract them from the content, how to express them in a compact way, and illustrates their use in concrete applications scenarios.