The state of the art of weld seam radiographic testing: Part II – Pattern recognition

Abstract

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 classification of weld discontinuities in continuous welds examined by radiography. There are basically two large types of research areas in this field: image processing, which consists in improving the quality of radiographic images and segmenting regions of interest in the images, and pattern recognition, which aims at detecting and classifying the discontinuities segmented in the images. Because of the complexity of the problem of detecting weld discontinuities, a large number of techniques have been investigated in these areas. This paper represents a state of the art report on weld testing and is divided into the two parts mentioned above: image processing and pattern recognition. The techniques presented are compared at each basic step of the development of the system for the identification of discontinuities in continuous welds. The first part of this paper (included in the June issue of this journal) dealt with image processing. This part deals with pattern recognition.