A Finite Element Skeleton approach as the articulation insensitivity shape descriptor

This paper presents a novel shape representation approach, Finite Element Skeleton (FES), based on studies of planar shape analysis from the perspective of Finite Element Method (FEM). First, we derive the shape contour of an object in image with edge detection approach. Then, the approach builds connections of all pixels on the shape contour with the inner center point of the shape, and models these virtual connections as bendable beam elements. Finally, we obtain a multi-degree-of-freedom (MDOF) model of the original shape. By this model, we can calculate its natural frequency, which is one of mechanical properties that directly related to the geometric shape, and employed it as the shape representation. FES shape descriptor possesses the natural properties on translation and rotation invariant. Especially, FES descriptor has the feature of articulation insensitivity which is the most important property of a shape descriptor to ensure a good performance of the intra-class similarity measurement. Experimental results validated that the proposed FES descriptor is capable of identifying shape for object recognition.