Before feature extraction, 300 facial images are normalized, which partially reduces the disadvantageous effect caused by size, angle and illumination rotations of the facial images.

• 在特征提取之前，本文对这300幅人脸图像进行了归一化预处理，部分地消除人脸图像因尺寸大小、角度旋转、光照强弱带来的不利影响。