Lukas Rosenthaler Friedrich Heitger Olaf Kübler Rüdiger von der Heydt Detection of General Edges and Keypoints. 78-86 1992 conf/eccv/1992 ECCV db/conf/eccv/eccv1992.html#RosenthalerHKH92 http://dx.doi.org/10.1007/3-540-55426-2_10