Image registration based on both feature and intensity matching

Image registration is one of the most important tasks in image processing. The algorithms of image registration are classified into two categories: the feature-based matching and intensity-based matching. Each of them has its strength and weakness. In this paper, by combining these two techniques together, we developed a new algorithm for image registration. The algorithm utilises a parametric projective model accounting for geometrical variation and a polynomial model with a small number of polynomial coefficients explicating the smooth spatially varying illumination variation. The initial projective model parameters are first estimated by using feature-based approach. Subsequently, the coefficients of the illumination model are determined simultaneously with the projective transformation parameters through the process of intensity matching. The experimental results demonstrated the algorithm is of robustness, efficiency and accuracy.