The geometrical feature of weld defect in assessing digital radiographic image

Digital Radiography is a filmless radiographic image that has been introduced to replace conventional film. It is one of the nondestructive techniques (NDT) that is used to indicate the internal condition of the sample being inspected. It is also an efficient technique in defect detection. Weld defect is any flaws that compromise the usefulness of finished weld specimen. The segmentation of weld defect in radiographic image is an important task which can be used for defect feature analysis by extracting its boundary. This study was performed to extract the weld defect and evaluate its geometrical feature. The boundary of defect is extracted by converting the image into binary form. The defect boundary is detected by recognizing the black pixel of eight neighborhoods of 3×3 filtering. The coordinates of the boundary pixel are stored and used to calculate the information of defect features. The information can be used by interpreter to interpret a defect.