Contrast-invariant feature point correspondence

Most existing feature-matching methods utilize texture correlation for feature matching, which is usually sensitive to contrast changes. This paper proposes a new feature-point matching algorithm that does not rely on the image texture. Instead, only the smoothness assumption, which states that the displacement field in a neighborhood is coherent (smooth), is used. In the proposed method, the collected correspondences of a group of feature points within a neighborhood are efficiently determined such that the coherence measure of the displacement field in the neighborhood is maximized. The experimental results show that the proposed method is invariant to contrast changes and significantly outperforms the conventional block-matching techniqu