Research On Three-Dimension Reconstruction Algorithm For Crack Defect Within Component

A series of 2D images which comprise the internal defect information can be obtained with CT scan easily, In some applications, this technology has significant limitations, because it needs the space-related imagination and experience of engineer to determine the three dimensional shape of internal defects. In practice, further precise determination of the density distribution within the defect, shape, spatial position, size and other information, you will need three-dimensional model of these slices images. This paper takes this as a background and carries on a series of research for the 3D reconstruction algorithm of slice-images for internal crack defect of important component systematically.Firstly, due to traditional surface reconstruction does not consider the relevance of adjacent slice images, we propose the surface reconstruction algorithm using feature tracking. Regional prediction, regional deformation and surface rendering are the key to the reconstruction of crak defect. Prediction is intended to estimate the region of following slice images based on the current image. Due to the difference between the predicted region and the actual region we can get the actual region through region morphing. Finally, the region is applied surface rendering to complete the Three-dimensional reconstruction. The algorithm can reduce unnecessary testing, and make the three-dimensional reconstruction of large-scale data possible especially when the crack region is a fraction of the entire body of data.Secondly, as most of current surface reconstruction methods can not obtain the inner information of defect, we propose a new method based on finite element mesh. The first step, extract the voxels of crack regions through image segmentation. Secondly, generate the mesh using the voxels extracted from the last step. Finally eliminate the jagged interfaces through surface smoothing. Thus, we can reconstruct the whole cracks, including surface and internal.Finally, reconstruction object is displayed by OpenGL. This paper constructs the whole framework of system, and defines some pivotal classes. The reconstruction System provides several browser windows, including, OpenGL support for the 3D interface, 2D images preprocessing interface, displaying all slice-images interface.