Antonio M. López Felipe Lumbreras Joan Serrat Creaseness from Level Set Extrinsic Curvature. 156-169 http://link.springer.de/link/service/series/0558/bibs/1407/14070156.htm 1998 conf/eccv/1998-2 ECCV (2) db/conf/eccv/eccv1998-2.html#LopezLS98