GUENSEL B ET AL: 'OBJECT-BASED VIDEO INDEXING FOR VIRTUAL STUDIO PRODUCTIONS', PROCEEDINGS OF THE IEEE COMPUTER SOCIETY CONFERENCE ON COMPUTER VISION AND PATTERN RECOGNITION,US,LOS ALAMITOS, IEEE COMP. SOC. PRESS, vol. CONF. 16, 1997, pages 769 - 774, XP000776575, ISBN: 0-7803-4236-4