1. A method for processing images of a scene, comprising: receiving image data of a reference frame and a current frame; selecting N registration points in the reference frame by identifying a plurality of candidate registration points in the reference frame based on at least one of an intensity value and an edge metric value, and selecting N registration points from among the identified candidate registration points based on a shape of an autocorrelation function; generating N motion vectors that describe motion of the image data within the scene by computing a correlation function on the reference and current frames at each of the selected N registration points; registering the image data of the current frame using a mapping of the motion of the scene derived from the N motion vectors to produce a registered current frame; and combining the image data of the registered current frame with image data of at least one previously registered frame to update the image data of the scene by spatially aligning the image data of the registered current frame with the image data of the at least one previously registered frame.