State-ofthe-Art of Weld Seam Inspection by Radiographic Testing : Part I – Image Processing

Over the last 30 years, there has been a large amount of research attempting to develop an automatic (or semiautomatic) system for the detection and classifica tion of weld defects in continuous welds examined by radiography. There are basically two large types of res earch areas in this field: image processing, which consis ts in improving the quality of radiographic images and segmenti ng regions of interest in the images, and pattern recognition, which aims at detecting and classifying the de f cts segmented in the images. Because of the complexity of the problem of detecting weld defects, a lar ge number of techniques have been investigated in these areas. This paper represents a state-of-the-art report on wel d inspection and is divided into the two parts mentioned above: image processing and pattern recognition. Th e tec niques presented are compared at each basic step of the development of the system for the identi fication of defects in continuous welds. This paper deals with the first part.

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