说明：   利用欧氏距离测试ar人脸数据库，该处的数据库经过了PCA降维处理； 训练样本为共计100个人的700幅图像降维数据 仅供参考，和交流之用。
( by using Euclidean distance test of AR face database, the database through the PCA dimension reduction training sample reduction data for 700 images of 100 individuals for reference purposes only, and the exchange of use)