@inproceedings{iccv2009MessingPalKautz, author = {Ross Messing and Chris Pal and Henry Kautz}, title = {Activity recognition using the velocity histories of tracked keypoints}, booktitle = {ICCV '09: Proceedings of the Twelfth IEEE International Conference on Computer Vision}, year = {2009}, publisher = {IEEE Computer Society}, address = {Washington, DC, USA}, }