A 3D vision-based inspection method for pairwise comparison of locally deformable 3D models

In this work we present a pairwise 3D vision-based inspection method for comparing locally deformable 3D models which refers to models whose parts have undergone some local deformation or change while the rest of the parts remained rigid and intact. In general, local deformations result from two types of transformations: non-volume conservative transformations caused by either the inflation or the deflation of models' parts and volume conservative transformations caused by bending, twisting, rotation or displacement of either internal or external parts of the model. The internal parts are the middle parts of an object, while the external parts are the parts on the extremity or the end of a part. We have experimented with different cases of deformations on man-made objects and mechanical parts for industrial inspection of possible defects, and for quality control purposes as well. We have also applied our pairwise comparison method on parts of the human body. Examples relevant to medical applications are the detection and inspection of a lesion which are also tested in this work. Our algorithm is not only successful for detecting local change but it also achieves high-accuracy results comparable to other well-known registration and industrial inspection techniques.