FFT based image registration

We present a new unified approach to FFT based image registration. Prior works divided the registration process into two stages: the first was based on phase correlation (PC) which provides pixel accurate registration [5], while the second step provides subpixel registration accuracy [1, 3]. By extending the PC method we derive a FFT based image registration algorithm which is able to estimate large translations with subpixel accuracy. The algorithm´s properties resemble those of the Gradient Methods [4] while outperforming it by exhibiting superior convergence range.