Visual Modeling Algorithm Of Multi-organizational Object Based On CT Images

With the development of CT,the performance of the equipment was improved greatly and the applications of CT was more and more widely,such as in medicine,industry,agriculture and petroleum geology.In the aspect of petroleum geology,core analysis by CT scanning techniques has become an important method,but it is still insufficient.A new visual modeling algorithm of multi-organizational object based on CT images is put forward by this article.This method is applied to petroleum geology and provides a new thinking in the analysis of the core.A visual software platform based on MFC single document platform and OpenGL technology was built,its data basis is CT images of the core.Firstly,multi-organizational model of petroleum geological core was established and the digital information can be get such as size,position,location of the core components by the use of this model.At last,skeleton of pore was extracted.It is the foundation to construct the pore network and do the research about pore structure and wettability on fluid flow properties.A series of modeling algorithm which aimed to build a multi-organizational model of the core from CT images was researched.It mainly includes following aspects:The appropriate segmentation algorithm based on the analysis of CT image of the core was selected firstly,and then multi-organizational point data was extracted according to the result of image segmentation.With the input of the point data,a surface model was established by using MC(marching cube)algorithm and also a solid tetrahedral mesh was established by constraint Delaunay algorithm based on point data and surface mesh.Then the property value of the solid tetrahedral mesh was assigned based on the property of the point data and the segmentation of tetrahedron was finished according to the property value.A new algorithm on the extraction of pore skeleton was put forward by this paper.This algorithm is totally based on geometry and mainly according to the adjacency relationship between circumscribed spheres of tetrahedron.Different data structures were created to realize data storage.Based on software platform and these structures,the visual display of the model and man-machine interactive operation was realized.At last,a series of CT images and a set of point data were imported to test our algorithm of multi-organization modeling and skeleton extraction.