“…The principal approaches in the second category are based on partitioning an image into regions that are similar according to a set of predefined criteria. Thresholding, region growing, histogram clustering, split-and-merge, and random fields are examples of methods of this category [1], [2], [10], [12], [13], [18], [30]. For our purposes, we briefly review the thresholding, histogram clustering, and split-and-merge algorithms.…”