1. A system for determining the distance of an object in a picture scene comprising: a pair of cameras spaced apart a known distance for converting left and right images of a picture scene including an object whose distance is to be found into left and right sets of pixel values along scan lines, and first signal processing means supplied with the pixel values of epipolar scan lines from each camera of said pair of cameras for finding a best match of pixels in the left image to pixels in the right image based on lowest global cost function of corresponding features along corresponding epipolar lines in each image subject to uniqueness, ordering and cohesivity constraints and for obtaining the disparity between the corresponding object in the scene in the left and right images along the pair of epipolar lines, and second signal processing means supplied with the disparity and with the known separation distance of said pair of cameras for providing a measurement of the distance of the object from said pair of cameras.