Employing Symmetric Subsets for Identifying Asymmetry of Human Skulls

This paper describes a technique for analyzing shapes with potential symmetry employing symmetric subsets. The proposed technique assumes that the shapes interested have potential bilateral symmetry. The notion of potential symmetry is given to those shapes with approximate or original symmetry. As respective examples, we can imagine a human face and a partial broken vase. Although their symmetric structures need be identified for their meaninghl analysis, very few researchers have ever discussed symmetry identification of those shapes with established symmetry finding technique such as the one employing moments of inertia [3] is applied to finding the plane of symmetry on a skull, the obtained plane will surely disagree with the plane one expects because of the asymmetry of the skull. Therefore the proposed technique is applied to the detection of its plane of symmetry. Identification of asymmetric part and evaluation of the a.cymmetry degree are then performed employing the plane of symmetry. Experimental results are shown based on CT images of a human head and discussion is given. potential symmetry. The present paper proposes a technique for identifying 2. OVERVIEW OF THE SYSTEM planes of symmetry on the shapes with potential bilateral symmetry employing the idea of symmetric subsets. The proposed technique is applied to asymmetry analysis of human skulls, and some experimental results employing real CT images of human heads are shown with discussion.