Lena Gorelick Moshe Blank Eli Shechtman Michal Irani Ronen Basri Actions as Space-Time Shapes. 2247-2253 2007 29 IEEE Trans. Pattern Anal. Mach. Intell. 12 http://doi.ieeecomputersociety.org/10.1109/TPAMI.2007.70711 db/journals/pami/pami29.html#GorelickBSIB07