3D CAD model extraction from image data of tomography

tomography means the image of layered/sliced intersection. Especially inmedical experiences, the physicians have been using these images to assess the locations ofabnormal formations with higher accuracy and to monitor human body without giving anyharm. In industry, they have significant role to analyze Non-Destructive Testing (NDT),investigation of inner structure of materials, dimensional measurements, density counting andmontage details of complex mechanic pieces for engineers and researchers.The ability of CAD modeling of an object without partly or completely digital data is calledas ?Reverse Engineering? in manufacturing engineering and it is developed with onlyphysical data.In this research, complex interior and exterior pieces are aimed to be modeled in 3-dimensional (3D) way by digitizing with the Computed Tomography (CT) instrument, andafter to compare the results of dimensional measurement and solid modeling with highaccuracy which are not to be handled with conventional measuring techniques. Radiology,digital image processing, Computer Aided Design (CAD) and Reverse Engineeringtechniques are combined together to achieve these objectives in this research.After digitizing the piece in tomography, intersection images were obtained to figure out thesurface data of sample in the experimental stage. Different image analyzing techniques wereused on these raster images by the MATLAB engineering software and 2-dimensional (2D)vector geometry were drawn by using Pascal Programming language. After, all the data weresent to MASTERCAM design software to obtain the exact modeling of the object. Finally, theobtained data was compared with either analyses on MIMICS reverse engineering software orscanning via COORD3 coordinate measuring machine and the above method and modelingwith CT were assessed with their advantageous and disadvantageous features.Keywords: Reverse Engineering (RE), Computed Tomography (CT), Digital ImageProcessing (DIP), Computer Aided Design (CAD).JURY:1 Prof. Dr. Erhan ALTAN (Supervisor) Date : 16.02.2006Doç. Dr. Ferhat D KMEN Page : 1402Yrd. Doç. Dr. Semih ÖNÜT3