State-of-the-Art of Weld Seam Inspection by Radiographic Testing:
Part I – Image Processing
Romeu Ricardo da Silva & Domingo Mery*
Departamento de Ciencia de la Computación
Pontificia Universidad Católica de Chile
*e-mail: dmery@ing.puc.cl
http://dmery.ing.puc.cl
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 defects 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 defects segmented in the images. Because of the
complexity of the problem of detecting weld defects, a large number of techniques have been investigated in
these areas. This paper represents a state-of-the-art report on weld inspection 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 defects in continuous welds. This paper
deals with the first part.
Keywords: Weld defects, nondestructive testing, radiography, automatic weld inspection, image analysis.