Shape from contour: straight homogeneous generalized cylinders and constant cross section generalized cylinders

We analyze the properties of straight homogeneous generalized cylinders (SHGCs) and constant cross section generalized cylinders (CGCs), and derive the types of symmetries that the limb boundaries and cross sections of these objects produce on the image plane. The constraints on the 3D shape of the objects are formulated based on the symmetries and from the geometry of the projection models. Finally, the methods that recover the 3D shape from the image of their contours are discussed and recovered surfaces are shown for sample objects