Statistical detection of circular and linear defects in radiographic images of welds

In this paper we investigate applicability of statistical techniques for defect detection in radiographic images of welds. The defect detection procedure consists in a statistical hypothesis testing using several nonparametric tests. A comparison of rules derived for image thresholding for a given level of false alarm is presented. In this work we consider circular defects such as cavities and voids, and linear flaws similar to cracks. Numerical experiments with real and test data are performed.