基于边缘对应的三维颅骨自动非刚性配准方法

针对三维颅骨模型在初始姿态相差较大以及存在较多缺失情况下自动配准困难的问题，提出一种基于边缘对应的三维颅骨非刚性自动配准方法。首先对待配准三维颅骨进行边缘提取，获得所有孔洞的边缘；然后根据边缘长度以及边缘间最短距离自动识别边缘类型，建立待配准颅骨和参考颅骨在边缘上的对应；之后对待配准颅骨的初始位置和姿态进行调整，实现粗配准；最后通过两次一致点漂移（CPD）算法逐步实现两个颅骨从边缘区域至所有区域的精确配准。实验结果表明，与常用的基于迭代最近点（ICP）和薄板样条函数（TPS）相结合的三维颅骨自动配准方法相比，该方法对姿态、位置、分辨率以及缺损具有更强的鲁棒性，并且配准效率更高。

Automatic nonrigid registration method for 3D skulls based on boundary correspondence

In order to automatically register the skulls that differ a lot in pose with the reference skull, or miss a large part of bones, an automatic nonrigid 3D skull registration method based on boundary correspondence was proposed. First, all the boundaries of target skull were calculated, and according to the edge length and the shortest distance between the edges, the edge type was identified automatically, and the correspondence between the registered skull and the reference skull was established. Based on that, the initial position and attitude of the skull were adjusted to realize the coarse registration. Finally, Coherent Point Drift (CPD) algorithm was used twice to realize the accurate registration of two skulls from the edge region to all regions. The experimental results show that, compared with the automatic registration method based on Iterative Closest Point (ICP) and Thin Plate Spline (TPS), the proposed method has stronger robustness in pose, position, resolution and defect, and has more availability.