REPRESENTATION OF MOTION ACTIVITY IN HIERARCHICAL LEVELS
FOR VIDEO INDEXING AND FILTERING


Xinding Sun*, B. S. Manjunath*, Ajay Divakaran +
* Dept. of Electrical and Computer Engineering
University of California at Santa Barbara,
Santa Barbara, CA 93106
E-mail: {xdsun, manj}@ece.ucsb.edu

+  Mitsubishi Electric Research Laboratories,
571 Central Avenue, #115
Murray Hill, NJ 07974
E-mail: {ajayd}@merl.com

Abstract

A method for video indexing and filtering based on motion
activity characteristics in hierarchical levels is proposed. To
extract motion activity information, an MPEG (MPEG-1/2)
video is first adaptively segmented into hierarchical levels with
fixed percentage of original video length based on P-frame
macroblock motion information. Three motion activity
characteristics-motion intensity which represents the degree of
change in motion, motion intensity histogram which represents
the temporal statistics of motion intensity, and spatial descriptor
which represents the spatial attribute of motion, are then
computed to represent different levels of video. The descriptors
from different levels are used selectively in different steps of
video indexing and filtering. Experimental results show the
proposed method is fast and effective, and provides a powerful
video indexing and filtering tool.