Object-Based Motion Activity Description in MPEG-7 for MPEG Compressed Video

摘要

In this paper, a novel descriptor in MPEG-7 is proposed to describe motion activities with both spatial distributions and spatial relationships within objects in consecutive frames of video shots. Initially, MPEG compressed video streams are fast segmented into video shots utilizing our GOP-based scene change detection approach. Moreover, the proposed object detection approach is imposed on each P-frame to obtain the information about the object size and its position. To describe motion activities in video segments with spatial relationships within objects, 2D-histogram in each P-frame is constructed further based on objects' coordinates of X and Y. 2D-histogram consists of X-coordinate and Y-coordinate histograms and is computationally low-complexity. The factor of the object size is considered and is weighted to accumulate the number of bins. In addition, the similarity matching measurement corresponding to 2D-histogram is proposed and used for the scenario of query by examples. Moreover, the experimental results show the effectiveness of the proposed scheme.