In this paper the problems of image processing in welding process have been studied

for example

how to detect the edge position of welding seam and to ascertain the size and shape of welding pool and so on. The traditional method of image processing is sensitive to noise and other disturbances

so it is difficult to process images accurately and timely. In order to overcome this deficiency

microcosmic and macrocosmic algorithms of image processing in welding were compared in this paper

then a novel composite image processing method using fractal theory was put forward. Based on the characteristics of images of welding process

regions were divided up according to fractal characters of image edge

and fuzzy regions including image edges were detected

then image edges were recognized using Laplace operator and curved by LSM (least square method). Experiment results show that the image edge of welding seam or welding pool can be recognized correctly and quickly. The new developed image processing method could provide reliable information for the real time control of welding process.