Detection and Imaging of Corrosion Defects in Steel Structures Based on Ultrasonic Digital Image Processing

作者：Dazhao Chi, Zhixian Xu, Haichun Liu · 发表于：Metals · 年份：2024 · DOI：10.3390/met14040390 · 被引用次数：12 · 研究领域：Industrial Vision Systems and Defect Detection、Advanced Measurement and Detection Methods、Optical Systems and Laser Technology

Corrosion is one of the critical factors leading to the failure of steel structures. Ultrasonic C-scans are widely used to identify corrosion damage. Limited by the range of C-scans, multiple C-scans are usually required to cover the whole component. Thus, stitching multiple C-scans into a panoramic image of the area under detection is necessary for interpreting non-destructive testing (NDT) data. In this paper, an image mosaic method for ultrasonic C-scan based on scale invariant feature transform (SIFT) is proposed. Firstly, to improve the success rate of registration, the difference in the probe starting position in two scans is used to filter the matching pairs of feature points obtained by SIFT. Secondly, dynamic programming methods are used to search for the optimal seam path. Finally, the pixels in the overlapping area are fused by fade-in and fade-out fusion along the seam line. The improved method has a higher success rate of registration and lower image distortion than the conventional method in the mosaic of ultrasonic C-scan images. Experimental results show that the proposed method can stitch multiple C-scan images of a testing block containing artificial defects into a panorama image effectively.