中文说明：代码中给出了基于PCA算法的人脸识别的详细步骤，具体过程，包括求平均脸，K-L变换，SVD分解，最后获得特征空间，训练样本400张，选取人脸数据库是ORL的，给出了具体的算法解释说明。
English Description：
Code gives detailed steps for face recognition based on PCA algorithm, process, including seeking the average face, k-l transform and SVD decomposition, and finally get the feature space, 400 training samples, select face database ORL, algorithms are given explanations.