中文说明：该代码主要实现的是基于PCA（主成分分析）的人脸识别程序，其中包含有人脸图像预处理、训练部分和测试部分这三大模块。测试用的照片是标准数据中的人脸图像，均为外国人脸。
English Description：
The code is implemented mainly based on PCA (principal component analysis) of the face recognition program, containing a human face image preprocessing, training and testing parts of three modules. Test photos are of face image in standard data, were foreigners face.