Nic Pillow Sven Utcke Andrew Zisserman Viewpoint-invariant representation of generalized cylinders using the symmetry set. 355-365 1995 13 Image Vision Comput. 5 http://dx.doi.org/10.1016/0262-8856(95)99722-D db/journals/ivc/ivc13.html#PillowUZ95