Parallel algorithm for gray-scale image segmentation

One of the classic algorithms of mathematical morphology is the image segmentation algorithm of Rosenfeld-Pfaltz. This algorithm in its "sequential" form, seeks to mark with a common label all connected pixels in an image, where the connectivity actually used in practice is 4-connectivity or 8-connectivity. The sequential Rosenfeld-Pfaltz algorithm (RS Algorithm) algorithm was presented for binary images; Cohen has previously presented a one-pass modification to the RS algorithm, and extended the algorithm to gray-scale. The RS algorithm is not simple to parallelise in principle, as pixels in a connected subregion may be connected only via a chain of connected pixels in several other sub-regions. We present here a parallelisable algorithm for segmenting into regions images of multiple gray-scale, based on the one-pass algorithm.