Research And Development Of Vectorization Technology On Industrial CT Images

Industrial CT (Computerized Tomography) is the advanced non-destructive testing technology that adopts rays to penetrate tested object and gains slice images. The technology is not affected by the characteristics of the tested objects such as material, shape and structure, and generates intuitionistic with high resolution. So the technology has the broad application prospects. However, the slice images gained by industrial CT scanning is the BMP format, it can not be directly applied to reverse engineering. So this dissertation researches the vectorization technology of industrial CT images and develops a vectorization system of industrial CT images. These establish the basic for the application of industrial CT in the feild of reverse engineering. Mainly works of the passage as follows:On the basis of analyzing the features of industrial CT images and the methods of existent edge detection, the dissertation adopts Canny algthoim to detect edge, and synthetically applies manual edit of BMP, contour tracking based on eight neighbor, the improved method of small gap filling and filtering based on rules to realize the preprocessing of edge gray images.Through analyzing the similarities and differences between vectorization of industrial CT images and vectorization of other images, the dissertation researchs contour subsection method based on extracting feature point, polygon fitting based on subsection and combination algorithm and improved arc fitting method based point of intersection of midnormal, and applies above those ways and five vector graphics editing functions to carry out contour vectorization. Lastly, the result of vectorization is exported by self-defined format of vector data and DXF and IGES formats of vector data that conform to the international standard.The vectorization system of industrial CT image has been developed by using OOP technology and C++ program language under the Windows XP operating system and Visual Studio 6.0 development environment. Mass experiments and the third testing indicate the system has good stability.