Research And Implementation Of Three-Dimensional Craniofacial Measurement And Similarity Assessment

Three-dimensional craniofacial measurement and its similarity assessment method is an important area in craniofacial reconstruction study. Craniofacial visualization, measurement method and similarity assessment method, which has provide a data basis and theoretical foundation for the pre and post stage of craniofacial reconstruction, are studied in this thesis. The main work is as follows:1. Craniofacial data preprocessing and its visualization. Two-dimensional medical image data is preprocessed, including image calibration, removal of noise and unrelated data, etc. Marching Cubes surface rendering algorithm and Ray casting volume rendering algorithm are used for reconstruction of three-dimensional models. OpenGL and VTK are adopted as auxiliary tools to reconstruct and visualize the models.2. Definition of feature points and its marking.40 feature points on the skin models and 26 on the skull models are defined according to the need of the project. Classification template method, which can ensure the accuracy of marking and is suitable for large amount of models, is proposed to effective marking feature points.3. Three-dimensional craniofacial measurement technique. Method of the three-dimensional craniofacial linear distance and angle measurement is studied and implemented in this paper. Cubic spline interpolation is used to calculate the curve distance and measurement of area and volume which is based on geometric models is proposed. Craniofacial soft tissue thickness of two-dimensional medical image and three-dimensional volume rendering model are calculated respectively.4. Craniofacial similarity assessment. Based on three-dimensional craniofacial measurement and with improved ICP algorithm, relative measurement algorithm and relative angle-context distribution algorithm, measurement results from three different angles before and after skin reconstruction are analyzed statistically and similarity of skin models is obtained. 5. Development of three-dimensional craniofacial measurement and similarity assessment system. According to the theoretical method proposed in this paper, three-dimensional craniofacial measurement and similarity assessment system (FaceMeaFaceSim) is designed and developed using VC and other assistant development tools. Display, measurement and similarity assessment of three-dimensional craniofacial model are achieved in this system.