Spherical harmonic correlation (SHC) is a robust registration algorithm that can bring two overlapping meshes into coarse rotational alignment. This is achieved by using the normals extracted from each mesh, as their relationship with each other is invariant to rotation and translation. A discrete representation of the normals is required by SHC, which equiangle binning achieves by equally dividing the polar and azimuthal angles. In the minimal literature that uses SHC for registration, the binning step has been overlooked, therefore we evaluate how different choices that relate to equiangle binning impact the alignment accuracy. These choices pertain to normalising by bin surface area, the orientation of normals and bandwidth selection. Testing is performed using three datasets with a priori known registration, thus providing an exact measure of rotational accuracy. The results show that mesh pairs with overlap as low as 9.2% were able to be correctly registered. It is found that registration performance can be improved when these aspects are taken into consideration.
['Robert L. Larkins', 'Michael J. Cree', 'Adrian A. Dorrington']
Evaluating Equiangle Binning for Spherical Harmonic Registration