Efficient Image Registration with Subpixel Accuracy using a Hybrid Fourier-based Approach

In many fields like medical imaging and remote sensing, it is necessary to register images with subpixel accuracy. A general problem is the tradeoff between accuracy and efficiency. This paper presents a highly accurate and efficient algorithm for subpixel image registration using Fourier-based cross correlation to determine the translation between two images. Therefore a coarse to fine strategy is used. It combines a fast method using image projections with an accurate approach using matrix multiplication for refined computation. The results show that the new approach has almost the same level of accuracy as the accurate method, but with reduced computational complexity. Compared to the fast method, the computational complexity of the new approach is slightly higher, but achievs a higher level of accuracy. Overall the hybrid approach achieves an efficient registration with a relatively short runtime.