Ridge detection by parallel reduction operations

In image processing, a gray-scale pattern can be transformed into a connected set of digital lines by repeatedly applying reduction operations, which remove suitable pixels belonging to the current border of the pattern, until no further pixel can be removed. To this purpose, algorithms based on parallel operations are of interest when multiprocessor architectures are available. We present such an algorithm, which detects the desired digital lines along the ridges or the gray-scale pattern, and show ìts capability to originate significant results also in case of pattems with non trivial distribution of gray-values.