Watershed segmentation based on hierarchical multi-scale modification of morphological gradient
WANG Xiao-peng, ZHAO Jun-jun, Ma Peng, YAO Li-juan · DOAJ (DOAJ: Directory of Open Access Journals) · 2017
Watershed segmentation is sensitive to noises and irregular details within the image,which frequently leads to a serious over-segmentation.Linear filtering before watershed segmentation can reduce over-segmentation to some extent,however,it often causes the position offset of object contours.For the purpose of reducing over-segmentation to preserve the location of object contours,the watershed segmentation based on the hierarchical multi-scale modification of morphological gradient is proposed.Firstly,multi-scale morphological filtering was employed to smooth the original image.Then,the gradient image was divided into multi-levels by the volume of three-dimension topographic relief,where the lower gradient layers were further modified by morphological closing with larger-sized structuring-elements,and the higher layers with the smaller one.In this way,most local minimums caused by irregular details and noises can be removed,while region contour positions corresponding to the target area were largely preserved.Finally,morphological watershed algorithm was employed to implement segmentation on the modified gradient image.The experimental results show that the proposed method can greatly reduce the over-segmentation of the watershed and avoid the position offset of the object contours.