Dynamic threshold selection based on local region in edge detection
边缘检测中局部区域的动态阈值选取方法*

Most of the current edge detection methods adopt global threshold selection techniques. However, global threshold selection sometimes is not adaptive to detect out important edges, whose gradient intensity are below it. In recent years, local threshold selection methods has developed, but the investigation is still insufficient and complicated to apply. Thus, in order to solve these problems,this paper proposed a method of dynamic threshold selection based on local region: each candidate edge point had two thresholds in local square region,where the point was in the center. Comparing the gradient of the edge point with the threshold, edge points can be picked out successfully. Experiments show that dynamic threshold selection has better results and little influence from noise than global thresholds selection used in Canny algorithm.