Abstract: Automatic 3D facial feature point extraction is a hot field of computer vision, which is widely used in face recognition, face model alignment, facial expression recognition, facial animation and other areas. By means of the statistical modeling of 3D face samples and the parameter optimization challenge in the number of for-matched models is solved by Genetic Algorithm（GA）. The 3D facial feature points can be calibrated automatically by using the model similarity matching method and its mapping relation. Firstly, the statistic models of 3D face model are constructed. Then get the mapping relation of the reference model and the matching model by the model deformation and then using the parameter about the number of for-matched model by Genetic Algorithm（GA） to generate the corresponding matching model. Secondly, calculate the similarity between the test model and matched model. Finally, the feature points of the model to be measured are indirectly obtained with the model similarity and the projection relationship. The experimental results show that the proposed algorithm is feasible and very effective. The method can automatically extract 3D face feature points. When the threshold value of the distance is 10 pixels, 39 of the 3D face feature points localization accuracy in this article can reach 100%. At the same time it can also solve the problem of traditional method of 3D face model smooth area feature point with low precision effectively.

Key words: feature point extraction, statistical deformable model, 3D face, Genetic Algorithm（GA）

摘要： 自动三维人脸特征点标定是计算机视觉领域的研究热点，其广泛应用于人脸识别，人脸模型配准，表情识别，脸部动画等领域。通过对三维人脸样本统计建模，采用遗传算法对待匹配模型的生成数目进行参数优化，利用模型相似性匹配方法及其映射关系对三维人脸特征点进行自动标定。首先，对三维人脸数据预处理，然后对其统计建模并通过模型形变得到有映射关系的基准模型和待匹配模型。利用遗传算法对待匹配模型中的待匹配模型生成数目参数进行优化，生成与之对应的待匹配模型数；接着计算待测模型与待匹配模型的相似度。最后，利用模型相似度和模型映射关系，间接得到待测模型的特征点。实验结果表明，提出的算法是可行的，能够在一定程度上提高原有算法的效率。该算法可以自动标定三维人脸模型的特征点，当距离阈值为10像素时，39个三维人脸特征点定位的准确率都可以达到100%，并有效解决了传统方法中三维人脸模型平滑区域特征点精度不高的问题。

关键词: 特征点标定, 统计可变形模型, 三维人脸, 遗传算法