3D Pipe Reconstruction From Multiple Calibrated Images

Methods for 3D pipe reconstruction from multiple calibrated Images are investigated based on the theory of photogrammetry. To get the center line and the radius of the pipe segments are the most important things of 3D pipes reconstruction. There are two kinds of pipe: one is the pipes with marks, mainly used when the radius of the pipe segments is big; the other is the pipes without marks, mainly used when the radius is small and the value of the radius is given.For the reconstruction of the pipes with marks, the thesis uses the active contour model to extract the edge of the marks, and then fits ellipse by least squares method. After using conics (ellipse) as primitives to complete the correspondence of the different images, the spatial circles are reconstructed. The thesis gets the centerline of the pipes through fitting the centers of the spatial circles with splines, and via averaging the radius of the spatial circles to receive the radius of the pipes which have the same radius.Experiments show that the active contour model takes the advantage of the gray difference between the marks and the pipes, so the edges are credible; and the method using the conics as primitives doesn't need point-to-point correspondence, the conics can totally correspond between two images. The result of the experiments shows the feasibility of this thesis.For the pipes without marks, the thesis realizes the reconstruction of the 3D centerline from multiple calibrated Images. By using the centerline, the thesis also reconstruct the pipes'3D model through sweeping method. Firstly gets the points on the centerline, secondly uses these points as primitives to search for correspondences through epipole constraint and dynamic method, and finally finishes the centerline reconstruction of the pipe by triangle method, instances are introduced to make a proof.