@inproceedings {Fidler2009a, author = {Sanja Fidler and Marko Boben and Ale\v{s} Leonardis}, url = {http://www.bmva.org/bmvc/2009/index.htm}, booktitle = {British Machine Vision Conference}, title = {Optimization framework for learning a hierarchical shape vocabulary for object class detection.}, year = {2009} }