In this work proposes a technique to detect some types of defects based on the radiography method. Inspection tests include two categories, destructive and nondestructive. One of the nondestructive tests is radiographic test that is used to detect internal defect. In addition, the image processing methods are used to improve defect detection in the radiographic images. The watershed technique is one of the segmentation methods that used to analyze images based on needed information. The proposed method in this paper is combination threshold and multistage watershed technique that applies to detect some of welding defects such as lack of fusion, wormholes, incomplete filled groove, and incomplete penetration. Otsu’s threshold leads to an increase in the contrast of the image and then multistep watershed transformation used to detect discontinuities and defect welding.
