Abstract: Systems and methods, which is based on preprocessing of a binary image into runs of adjacent white pixels, rapidly labels the connected components of the binary image, calculates the ellipse parameters of the connected regions, identifies connected regions which are distant from known foreground regions, and identifies those pixels whose Euclidean distance from the input binary mask is between two thresholds. The execution time of the first phase, the scanning of the input image and identification of adjacent runs of white pixels, scales as the number of pixels, is CPU memory cache sensitive, and very simple. The execution time of the subsequent processing stages for the various components of the systems and methods scale as the number of runs of pixels, so in most cases, for large input images, is considerably faster than conventional processes, which scale as the number of pixels.