Motion and shape signatures for object-based indexing of MPEG-4 compressed video

The emerging MPEG-4 standard enables direct access to individual objects in the video stream, along with boundary/shape, texture, and motion information about each object. This paper proposes an object-based video indexing method that is directly applicable to the MPEG-4 compressed video bitstreams. The method aims to provide object-based content-interactivity; thus, defines the audio-visual object as the indexing unit. The scheme involves object-based temporal segmentation of the video bit-stream, selection of key-frames and key-video-object-planes, and characterization of the motion and/or shape of each video object including the background object. We also propose syntax and semantics for an indexing field to meet the content-based access requirement of MPEG-4. Experimental results are shown on two MPEG-4 test sequences.