Extracting borderline of CO₂ arc welding molten pool image using gray-scale morphology

For CO₂ arc welding molten pool image, there are too many point and line noises, so it is difficulty to accurately extract borderline of molten pool image.We made use of the image processing technology of gray-scale morphology based on mathematical morphology and design the filter figure and operation order by means of moments-preserving method to extract successfully borderline of molten pool image of CO₂ arc welding.So the processed image provides useful molten pool information for welding process control and welding quality control.