<title>Video copy detection using spatio-temporal sequence matching</title>

Abstract

This paper proposes a novel sequence matching technique to detect copies of a video clip. This copy detection scheme can be used as either an alternative approach or a complementary approach to watermarking for copyright protection. It can also be used for media tracking. A challenge is that the different digitizing and encoding processes give rise to several distortions, such as changes in brightness, changes in color, different blocky artifacts, changes in frame format, and so on. While there exist several algorithms proposed, most of them focus on coping with signal distortions introduced by different encoding parameters. However, we note techniques to deal with aspect ratio conversions must be evenly taken into account because those conversions are frequent in practice. To this end, each image frame is partitioned into 2x2 by intensity averaging, and the partitioned values are stored for indexing and matching. Our spatio-temporal approach combines spatial matching of ordinal signatures obtained from the partitions of each frame and temporal matching of temporal signatures from the temporal trails of the partitions. The efficacy of the proposed method has been extensively tested and the results show the proposed scheme is efficient to deal with various modifications.