SIFT特征点检测算法是一种有效的图像特征检测法，对旋转、尺度，光照变化都具有一定的鲁棒性。-SIFT feature detection algorithm is an effective method of image features, rotate, scale, the light changes robustness。

这是一个人脸图像的几何预处理的代码，主要有人眼检测，旋转以及剪裁与缩放-This is a face image preprocessing of the geometry of the code, the main someone eye detection, rotate and clipping and zoom