Comparison of image alignment on hexagonal and square lattices

A hexagonal lattice has been researched to improve computer vision and image processing. However, image alignment on the lattice has not been fully discussed yet. In this paper, we perform image alignment on hexagonal and square lattices. Then we compare and evaluate them. We used hexagonal lattices of two sizes. One has the same pixel interval between adjacent pixels as the square lattice, which results in higher resolution than the square one. Another has the same pixel area as the square lattice, which has the same resolution as the square one. The results show that the image alignment of both the hexagonal lattices outperforms that of the square lattice with respect to accuracy and the success rate. Importantly, the results also show that converting an existing large image on the square lattice into the smaller image on the hexagonal ones of both the sizes could improve image alignment.