1. A method for determining a deblurred image, the method implemented at least in part by a data processing system and comprising: a) receiving a sharp image of a scene captured with a short exposure time; b) receiving a blurred image of the scene captured with a longer exposure time than the sharp image, wherein the blurred image has a higher level of motion blur than the sharp image; c) determining a blur kernel responsive to the sharp image and the blurred image; d) determining one or more reference differential images responsive to the sharp image, wherein each pixel of a particular reference differential image is determined by computing a difference between the corresponding pixel in the sharp image and a nearby pixel in the sharp image at a predefined relative position, wherein each differential digital image is associated with a different predefined relative position; e) defining an energy function that includes an image differential term that is a function of differences between the reference differential images and a corresponding set of candidate differential images computed for a candidate deblurred image, wherein the candidate differential images for the candidate deblurred image are computed using the predefined relative positions associated with the corresponding reference differential images; f) determining a deblurred image responsive to the blurred image and the blur kernel by evaluating candidate deblurred images using the energy function; and g) storing the deblurred image in a processor-accessible memory system.