通过PCA 算法提取特征脸 在人脸训练库中获取每张人脸的特征脸，在测试集中寻找与训练的人脸相似的人脸。有可视化的GUI界面。(The feature face is extracted by PCA algorithm to get the face of each face in the face training library, and the face which is similar to the trained face is found in the test set. There