三维视觉计算与机器人研究室三维形态分析及其在古人类学研究中的应用Shape Analysis of 3-D Objects on Paleoanthropology

通过比较出土化石形态上的差异来分析古人类生存和活动的状态是古人类学研究的基本方法。借助三维激光扫描技术，我们可以获取化石精确的三维模型。然后运用计算机手段进行化石表面局部形状的分析，获取传统的形态测量手段所无法得到的化石形状信息。The analysis of shape similarity of unearthed fossils is a fundamental part of paleoanthropology research. We can construct the exact 3D model of the fossil by means of technology of laser scanning and then analyse the local shape variation between two models to find more useful information than what traditional morphometrics can do.

标有标志点的现代人头骨

比较对象的选取 （ Selection of Comparable Object ）同源性是古人类学研究中对于研究对象的基本要求，因此我们选择能够表征生物进化特征的标志点作为研究的基本对象。传统的形态测量方法仅利用两个特征点集合之间的差异来描述研究对象整体的形状变化。我们以生物标志点为基础，通过找到标志点间的测地线得到进行比较的局部表面。Landmarks, located according to some rule, are presumed to correspond in some sensible way over the forms of a data set, which is called homology. In our method, which is a landmark-based morphometric method, we find the geodesics among landmarks which define an area to be analyzed in the model surface.

形状相似性度量 （ Measurement of Shape Similarity ）选定比较的区域后，我们需要定义对象之间形状相似性的度量。当前我们选择曲率直方图作为度量的参考量，用直方图间的差异来度量模型表面形状的差异。另外，我们也可以定义一种变换，将两个模型表面形状的差异表示为由一种模型到另一种模型的变换。After we have selected the area to be analyzed in the model surface, a measurement of shape similarity is necessary. We define curvature histogram as our measurement of shape similarity, which can describe shape similarity of two objects rightly. Otherwise, we can define a kind of transform from one object to the other to describe the shape similarity of two objects.

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由测地线得到的比较区域