1. A computer-implemented process for segmenting and estimating the optical flow between a pair of images of a scene, comprising using a computer to perform the following process actions: establishing an initial segmentation for each image; establishing an initial optical flow estimate for each segment of each image, wherein the optical flow estimate is the estimate of a translation that describes any movement of the segment from a position in one of the images to a position of the segment as seen in the other image; computing a refined optical flow estimate for each segment of a first one of the images from the initial segmentation of that image and the initial optical flow of the segments of that image; and computing a refined optical flow estimate for each segment of the second image from the initial segmentation of that image and the initial optical flow of the segments of that image.