A Simple Algorithm for Defect Detection From a Few Radiographies

The paper concerns the radiographic nondestructive testing of well-manufactured objects. The detection of anomalies is addressed from the statistical point of view as a binary hypothesis testing problem with nonlinear nuisance parameters. A new simple and numerically stable detection scheme is proposed as an alternative to the conventional generalized likelihood ratio test which becomes untractable in the non-linear case. This original decision rule detects the anomalies with a loss of a negligible part of optimality with respect to an optimal test designed for the “closest” hypothesis testing problem with linear nuisance parameters. The inspection of nuclear fuel rods is discussed to illustrate the relevance of the proposed theoretical solution.