Optical-Flow Perspective Invariant Registration

In this paper we examine the causes of one of the major shortcomings of current natural feature registration approaches, failure to register when the camera´s view approaches parallel to the marker. The methods used by current registration algorithms in the attempt to overcome this problem are reviewed, and a novel tracking based approach called the Optical-flow Perspective Invariant Registration Augmentation (OPIRA) is presented which significantly improves the range of registration. A thorough evaluation of OPIRA is conducted using an external ground truth, showing the improvements possible when combined with leading natural feature registration algorithms such as SIFT, SURF and Ferns.