A welding defect detection model based on a shape-aware network

Abstract

Because X-ray welding images have complex backgrounds and welding defects have different sizes and shapes, effectively detecting welding defects in X-ray images is still a challenge. To solve these problems, a shape-aware network (SA-NET) was proposed, whose core was the shape-aware module (SAM). SAM includes a free-shape region proposal network (FS-RPN) and a two-level regression head (TR-Head). FS-RPN predicts the shape of the anchor boxes corresponding to each position on the feature maps, and aligns the feature maps according to the predicted anchor box shape. Then, the offset and the foreground classification score of the anchor boxes are predicted according to the aligned feature maps. Thus, FS-RPN generates the proposal regions with a higher quality. TR-Head uses the first-level detection head, which only contains one regression branch, to further improve the quality of the proposal regions by fine-tuning the proposal regions. It employs the second-level detection head, which consists of one classification branch and one regression branch, to predict the categories and the boxes of defects. The experimental results showed that SA-NET effectively improved the quality of the proposal regions and greatly improved the detection effect of welding defects, especially defects with special shapes.