中文说明：
用于人脸特征提取的2D2DLDA、2D2DLPP、2D2DPCA算法，由原本的一维特征提取改善为二维特征提取，大大提高了其识别率。
English Description：
2d2dlda, 2d2dlpp and 2d2dpca algorithms for face feature extraction are improved from one-dimensional feature extraction to two-dimensional feature extraction, which greatly improves the recognition rate.