Shehzad Khalid Andrew Naftel Evaluation of Matching Metrics for Trajectory-Based Indexing and Retrieval of Video Clips. 242-249 2005 conf/wacv/2005 WACV/MOTION http://doi.ieeecomputersociety.org/10.1109/ACVMOT.2005.49 db/conf/wacv/wacv2005.html#KhalidN05