pca算法已经广泛应用于各方面，当提取的图像特征维度比较高时，为了简化计算量以及储存空间，需要对这些高维数据进行一定程度上的降维，并尽量保证数据的不失真。-pca algorithm has been widely used in various areas, when the extracted image feature dimension is relatively high, in order to simplify the calculation and storage space needed for these high-dimensional data for a certain degree of reduced dimensions, and try to ensure data is not distorted.