Reliable rejection of mismatching candidates for efficient ZNCC template matching

This paper presents a method that reduces the computational cost of template matching based on the zero-mean normalized cross-correlation (ZNCC) without compromising the accuracy of the results. A very effective condition is determined at a small and fixed cost that allow to rapidly detect a large number of mismatching candidates with no need to compute the ZNCC score. Then, thanks to the use of an additional set of conditions, the computation of the whole ZNCC function is typically required only for a very small number of candidates. Experimental results demonstrate the effectiveness of our approach.