Weld seam surface detect feature extraction method based on grayscale image morphology

Abstract

The invention relates to a weld seam surface defect feature extraction method based on the grayscale image morphology, which comprises the steps of setting shooting parameters of a miniature CCD camera according to an acquired image; converting the acquired true color image into a grayscale image, and carrying out median filtering processing on the image; eliminating a white interference region generated by residue noise and background texture by adopting a minimum area deleting method; avoiding influences imposed on edge line extraction by an undetermined black region through region filling processing; processing a completely filled weld seam region through an expansion algorithm so as to acquire a weld seam region whose area is identical to the actual weld seam area; extracting an edge line of the filled and expanded weld seam region by adopting a Canny operator so as to realize positioning for the weld seam region; and drawing a cross section grayscale B scanning curve which is vertical with the weld seam edge, wherein a gray-scale value of the weld seam surface changes obviously on the B scanning curve when the weld seam surface has defects such as a hole and an overlap, so that different types of defects at the weld seam surface are judged. The weld seam surface detect feature extraction method realizes accurate positioning for the weld seam edge and accurate recognition for the defects such as overlaps and holes.

Description

technical field [0001] The invention relates to a method for detecting welding seam defects, in particular to a method for detecting and identifying weld seam defects based on image processing technology. The method is applicable to the detection and identification of welding defects in internal welds of energy-transforming equipment such as pipelines, boilers, and headers, and belongs to the field of non-destructive testing. Background technique [0002] With the development of my country's industrial industry, boilers, pipes, headers and other energy-transforming equipment are the key components to withstand high temperature and high pressure, and their manufacturing quality has attracted more and more attention. Transducer equipment not only bears the internal pressure caused by the action of the medium, but also bears the stress caused by the temperature difference between the inside and the outside, and the failure and damage can easily occur in the internal welding are...

AI Technical Summary

Problems solved by technology

[0005] At present, the technology of welding seam inspection based on X-rays is mostly aimed at the detection of internal defects of weld seam welding, and there is little research on the technology of detection and identification of surface defects of internal welding seams

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