Ady Ecker Shimon Ullman A Hierarchical Non-Parametric Method for Capturing Non-Rigid Deformations. 50-56 2005 conf/crv/2005 CRV http://doi.ieeecomputersociety.org/10.1109/CRV.2005.6 db/conf/crv/crv2005.html#EckerU05