中文说明：PCA算法（主成分分析算法），通过对多维数据的降维算法，达到图像降维的目的，把关键信息存储在更低的维度，可用于人脸特征识别匹配的多种途径。
English Description：
PCA algorithm (principal component analysis algorithm) achieves the purpose of image dimensionality reduction through the dimensionality reduction algorithm of multi-dimensional data, and stores the key information in a lower dimension, which can be used in many ways of face feature recognition and matching.