分水岭分割方法，是一种基于拓扑理论的数学形态学的分割方法，其基本思想是把图像看作是测地学上的拓扑地貌，图像中每一点像素的灰度值表示该点的海拔高度，每一个局部极小值及其影响区域称为集水盆，而集水盆的边界则形成分水岭。分水岭的概念和形成可以通过模拟浸入过程来说明。在每一个局部极小值表面，刺穿一个小孔，然后把整个模型慢慢浸入水中，随着浸入的加深，每一个局部极小值的影响域慢慢向外扩展，在两个集水盆汇合处构筑大坝，即形成分水岭。(Watershed segmentation method, a segmentation method based on mathematical morphology and topology theory, its basic idea is that the image as a geodesic on the topological features, each pixel of the image gray value of the said at the altitude, every local minimum and the influence area is known as the water collecting basin, and the catchment boundary is the formation of watershed. The concept and formation of watersheds can be explained by simulated immersion processes. The surface of the value in every local minimum, pierce a hole, and then the whole model is slowly immersed in water, with the immersion deepening, the influence domain of each local minimum and slowly expand outward, to build a dam in the two water collecting basin confluence, which form a water ling.)