Rotation-invariant template matching based on ring projection and orientation codes

A fast rotation-invariant template matching method based on Ring Projection Transform(RPT) and Orientation Codes(OC) is proposed. The method consists of two stages. In the first stage, a ring projection method is applied to convert 2D image patches into ID vectors, based on which a rotation-invariant similarity measure is designed. In the second stage, a template matching process based on OC is performed on a limited number of candidates selected by applying the similarity measure, leading to the high computational efficiency. The experimental results indicate that the matching accuracy of the proposed algorithm is superior to RPT and OC method.