Study And Achievement On Techniques Of 3D STL Reconstruction Based On Industrial CT Slicing Image

ICT (Industrial Computed Tomography), owing to the feature of being able to display the inner structure, composition, material and default status of the inspected objects with 2D slicing image, clearly, accurately, intuitively and without any loss to the inspected objects, is awarded as the best inspection technology without loss nowadays. In area of advanced manufacturing technology, Rapid Reverse Engineering based on ICT slicing image becomes a focus on research. Its emphasis lies in from industrial slicing images generating the datum, which can be accepted by rapid prototyping equipment. In this dissertation, some key technologies related to it were researched.This thesis's emphasis lies in from industrial slicing images generating the datum, which can be accepted by rapid prototyping equipment. Some key technologies related to it were researched, and then developed some parts of the ICT Reconstruction system.First of all, contour extraction of ICT slicing image was accomplished. For the serious noise in Practical ICT images, after analyzing source and characteristic of the noise in ICT images, combined with existing classical filtering algorithm, a adaptive mixed-weighted hybrid filtering was proposed, which can remove noise and be able to maintain the details of the image information; The eight-neighbor method was chose to contour extracting and contour tracking, output the 3-D coordinate of the contour as txt format that was the base of the follow-up works.Secondly, after recognized the in-out feature of the contours, an algorithm based on ellipse-fitting and fast Hausdroff distance was proposed to match the contour of the ICT image slices, This algorithm not only be able to quickly and accurately achieve contour matching, but also have accurate matching result with the bifurcation of the contour; aimed at the large quantity of the cloud, the algorithm based on the curvature was adopted to reduce the cloud date; introduced the STL file format and kinds of regular algorithm in filling between layers, and the smallest angle algorithm, which was rather fit to this dissertation, was adopted in this dissertation; aimed at the bifurcation of the contour, Rotating split-half method was introduced to the triangle meshing of contour loops, Resolved the filling questions of the bifurcation part; The triangle meshes were written to form the STL file that can be accepted by rapid prototype manufacturing.In the end, the software was developed to achieve the function. In contrast with the method of using exiting CAD software to make STL file after reconstructing the CAD model, the correctness of the result and feasibility of the method in this dissertation was verified, moreover, the develop periods was shortened.