Sensitivity is different for different differential operators,how to choose a suitable edge detection operator to obtain exact information of edge,is the essential step for fracture surface image.

• 不同的微分算子对边缘的敏感程度是不同的,如何选用适当的边缘检测算子得到准确的边缘信息,就成为断口图像处理的关键步骤。