Ondrej Drbohlav Radim Sára Specularities Reduce Ambiguity of Uncalibrated Photometric Stereo. 46-62 2002 conf/eccv/2002-2 ECCV (2) http://link.springer.de/link/service/series/0558/bibs/2351/23510046.htm db/conf/eccv/eccv2002-2.html#DrbohlavS02