Fábio Gagliardi Cozman Eric Krotkov 801-806 1997 conf/cvpr/1997 CVPR https://doi.org/10.1109/CVPR.1997.609419 https://doi.ieeecomputersociety.org/10.1109/CVPR.1997.609419 db/conf/cvpr/cvpr1997.html#CozmanK97