傅楸善臺灣大學：資訊工程學研究所陳律閎Chen, Lu-HongLu-HongChen2007-11-262018-07-052007-11-262018-07-052004http://ntur.lib.ntu.edu.tw//handle/246246/53952We propose a method to automatically generate the skeleton of a 3D model by using principal curves since the definition of principal curves (smooth curves that pass the “middle” of a cloud of points) is similar to the definition of medial axis. At the beginning, an initial skeleton to roughly capture the topology of the model is given. The initial skeleton may be generated by user manually, by other existing automatic methods, or even by an existing skeleton of other similar model. Then, a fitting-and-smoothing algorithm is applied to adjust the skeleton to fit the definition of principal curve. If the result skeleton is noisy, an optional reconstruction method can be applied to remove some noises. The results indicate that the proposed method finds smooth skeletons of a wide variety of models with different initializations. Our method is able to generate the skeleton of a 3D model within minutes on a Pentium IV 2.8 GHz PC. The algorithm is especially faster if the given initial skeleton is from the skeleton of a similar model or from the same model in different poses.Abstract................................................1 1. Introduction...................................2 2. Previous Works.................................3 (1) MAT............................................3 (2) Reeb Graph Method..............................5 (3) Repulsive Force Field..........................5 3. Principal Curve................................7 4. Algorithm......................................9 (1) Projection.....................................10 (2) Cost Function and Smoothness...................10 (3) Vertex Optimization............................11 (4) Adding a Vertex................................13 (5) Reconstruction.................................13 (6) Complexity.....................................13 5. Experimental Results...........................14 (1) Initialized by Other Methods...................14 (2) Initialized by the Skeleton of Similar Models..17 (3) Initialized by the Skeleton of Different Poses.20 6. Conclusion and Future Works....................22 7. Reference......................................231610135 bytesapplication/pdfen-US主軸曲線骨幹principal curveskeletonthesis