Defects in a weld: a complete radiographies processing line

We propose in this article a complete acquisition and processing line of weld radiographies, from which must be highlighted cavity shaped defects. The main features of the films are a high optical density, a strong inhomogeneous background in both directions and a weak contrast. We present the study of three trend removal methods allowing improvement of the signal/noise ratio of the edges pictures. The segmentation is derived from the edges picture by the mean of a constrained watershed algorithm. The constraints are deduced in an automatic way from the shape of the histogram.