Solving the orientation-duality problem for a circular feature in motion

Circular features have been commonly used in numerous computer vision application areas for 3D pose estimation. However, although the 3D position of the circle's center can be uniquely identified, the solution process yields two different feasible orientations, of which only one is the true solution. In this paper, two methods are presented for the solution of the orientation-duality problem for circular features that are in motion. The first approach is applicable to those features moving on a 3D line with constant orientation or to those which are moving on a plane with general motion. The second approach relies on the existence of additional object features, such as points or lines, which are coplanar to the circular feature. In this case, the circular feature can undergo an arbitrary 3D motion. Experimental results verify the validity of the proposed methods