Documentation for Video/MotionActivity

Technique Motion Activity
Document MPEG-7 Visual (ISO/IEC 15938-3)
Name Ajay Divakaran (Mitsubishi Electric Research Labs.)
EMail ajayd@merl.com
Contact ajayd@merl.com
Type Application
External Libraries none
Related Ds/DSs Video Segment DS
Used Ds/DSs none
Input Video
Extraction Yes
Client Appl Search & Retrieval
Summary This library implements the motion activity descriptor which consists of one primary and four secondary attributes. The primary attribute is the intensity of motion activity, and the other four attributes express the dominant direction, the spatial distribution, the temporal distribution and the spatial localization of motion activity. Since the feature vector is short, a simple absolute distance or squared distance criterion can be used for matching.
Strong Points The descriptor is compact and extremely effective as a filter for reduction of large search spaces.
Limitations The program depends on previously computed motion vectors. It does not have its own motion estimation. This was done to maintain format independence.
Known Problems None.
Parameters None.