A qualitative approach to quantitative recovery of SHGCs shape and pose from shading and contour

A qualitative approach to quantitatively recovering the shape and pose of a straight homogeneous generalized cylinder (SHGC) based on a weak Lambertian assumption is described. This assumption relaxes the strict cosine law of the Lambertian reflection model. The method does not need to know the lighting condition or surface albedo. The image of the projection of the axis of an SHGC is extracted. The slant angle of the SHGC is estimated using the weak Lambertian assumption along an extremal cross-section curve. The location of the SHGC´s 3-D axis on other parallels is located. As a result, the pose (slant and tilt) and the shape (the shape of the cross section, the location of the axis, and the sweeping function) of an SHGC are recovered. Experimental results for both synthesized and real images are shown