1. A computer-implemented method of registering a first image and a second image, the method comprising computer-implemented acts of: logically dividing the first image into a first plurality of regions; logically dividing the second image into a second plurality of regions; projecting the first plurality of regions and the second plurality of regions into a lower dimensional space using random projections; determining, for each of the projected first plurality of regions, at least one of the projected second plurality of regions that is closest according to first criteria; and determining a transform that brings each of the projected first plurality of regions into a closest correspondence with the respective at least one of the projected second plurality of regions according to second criteria, the transform indicating the registration of the first image and the second image.