Abstract: It has been a hot issue and difficulty in recent research to gradually reduce the dependence on manual identification by automatic identification of defects in radiographic inspection films. Due to the limitations of professional fields, technicians good at image identification do not know much about radiographic testing technology. Therefore, in order to do a good job in automatic identification of negative films, it is necessary for technicians to fully grasp the characteristics of defect images in radiographic films and the key factors affecting the identification including low transparency of negative film, small defect size, image edge blur, edge erosion effect, image deformation, imaging difference of area type defect, overlapping imaging, human factors, differences in standards or regulations and so on. This paper analyzes and studies the characteristics and key factors so as to provide reference for technicians engaged in automatic identification of radiographic inspection films to accurately grasp the image characteristics and elements of film defects.

Key words: radiographic testing, defect image, identification, imaging factors, automatic film evaluation