With the innovation in 3D modeling software, more and more 3D models are becoming
available in recent decades. To facilitate efficient retrieval and search of large 3D model
databases, an effective shape classification algorithm is badly in need. In this paper, we
propose a new feature descriptor named Principal Thickness Images (PTI) that encodes the
boundary surface and the voxelized constituents of a 3D shape into three gray-scale
images. With the support of PTI, we extend the kernel sparse representation-based�…