以对接焊缝不同区域分布矩形槽缺陷的漏磁图像为对象，提出一种基于数学形态学的焊缝和缺陷的边缘提取方法。首先利用经典边缘检测算子对焊道上分布矩形槽缺陷和热影响区分布矩形槽缺陷进行边缘提取，检测结果说明了经典算子的不适用性。针对焊缝不同区域分布矩形槽缺陷漏磁图像，利用数学形态学算法，构造圆盘形结构元素进行边缘提取。结果表明：基于灰度膨胀变换的边缘检测算法，可较准确地提取漏磁信号图像的焊缝和缺陷边界，实现焊缝和缺陷二者的有效分离，具有一定的可行性和实用性。

Taking the magnetic flux leakage (MFL) image of the rectangular slot defect in the different regions of the butt weld as the research object, a new edge extraction method for the weld and the defect is proposed based on the mathematical morphology. Firstly, the classical edge detection operators extract the edge for the rectangular slot defects in the weld and the rectangular slot defects in the heat affected zone, the test results verify the inaplicability of the classical operators. Then aiming at the above-mentioned rectangular slot defect in the different regions, mathematical morphology algorithm was used to, and extract the edge by the disc-shaped configuration. The outcome indicates that the edge detection algorithm based on gray-scale expansion transform can extract the MFL signal image of the weld and the defect boundaries, the both are separated effectively, and the method has a good adaptability and practicality.