Shape-based pose estimation evaluation using expectivity index artifacts

This paper recommends the use of three distinct shape artifacts to evaluate shape-based pose estimation systems, and provide their rationale. These artifacts are the Reduced Pose Ambiguity Cuboctohedron (RPAC), a cube, and an 80-triangle tessellated sphere. The rationale for these shapes derives from the range of Expectivity Index (EI) values and ambiguity intervals. The EI varies inversely with expected pose estimation error for a given shape and view, and the ambiguity interval describes a distance between symmetries where a shape fits with the incorrect pose as precisely as with the correct one. These concepts are discussed in detail and used to define the proposed shapes as good for covering a range of circumstances for performance evaluation of shape-based post estimation systems, and are proposed for inclusion in the ASTM E57.02 standards for pose estimation evaluation.