1. A computer process of detecting the presence of a contour in an image formed on an array of pixels comprising: calculating the x and y gradients Gx and Gy at each pixel in the array, generating a plurality of paths each corresponding in shape to the shape of said contour and fixing a single predetermined point in each path at a pixel in said array, each path being fixed at a different pixel, for each path, proceeding from the pixel at said predetermined point on the path to the next pixel on the path, accumulating in an accumulator the gradient at the next pixel by adding or subtracting the horizontal gradient Gx where the movement to the next pixel was up or down, respectively, or subtracting or adding the vertical gradient Gy where the movement along the path to the next pixel was to the right or left, respectively, then proceeding to the next pixel on said path in said selected direction, accumulating in the accumulator as in said preceding step, and continuing the procedure until said path is traced to the pixel at said predetermined point, whereat the accumulated value in the accumulator for each pixel at said predetermined point is the pixel value for a pixel in a transformed image, and the transformed image indicates the detection of the contour by exhibiting a fovea.