Three-dimensional reconstruction filtering algorithm based on single ray picture of pipe welds

Abstract

With constraints in single image, such as collinear equations and coplanarity, a real-scale object model can be obtained, and real scenes of regular objects can be reconstructed, by using three-dimensional reconstruction algorithms such as grid processing and interpolation fitting. A 3D reconstruction algorithm based on single pipe weld seam ray picture is proposed. Firstly, recognizing and segmenting the weld image, and using non-linear filtering to enhance the gray level of the image. Secondly, identifying the inner and outer edge positions of the weld, and performing threshold segmentation, morphological filtering, connected area detection, edge detection, line detection, image rotation, and inner wall area extraction. Thirdly, based on the image of the elliptical opening of the weld seam, the inverse perspective transformation is used to restore the formation of the weld seam root and the weld 3D scatter points. Finally, 3D point cloud is meshed, the function of point-to-surface is achieved, and a three-dimensional model of the welding tumor is generated. The experimental results demonstrate that the algorithm can accurately and effectively perform 3D reconstruction of the weld seam based on a single 2D pipe radiograph of the weld seam, and realize accurate identification of the weld nodules at the root of the pipe through-flow weld.