Image registration using blur-invariant phase correlation

In this paper, we propose an image registration method, which is invariant to centrally symmetric blur. The method utilizes the phase of the images and has its roots on phase correlation (PC) registration. We show how the even powers of the normalized Fourier transform of an image are invariant to centrally symmetric blur, such as motion or out-of-focus blur. We then use these results to propose blur-invariant phase correlation. The method has been compared to PC registration with excellent results. With a subpixel extension of PC registration, the method achieves subpixel accuracy for even heavily blurred images.