• 来源：**

  https://www.cnblogs.com/YouXiangLiThon/p/14246094.html

  **

其实，通过代码：git clone下来的（这里是最新的opencv4.5.1）在 opencv/.cahe/ 文件夹下面的文件有：

ade data ippicv xfeatures2d，其中， data ippicv xfeatures2d 里面的文件都没有，data下面是 7505c44ca4eb54b4ab1e4777cb96ac05-face_landmark_model.dat

要自己去下载这个数据，可以到github上面下载（之前给的csdn连接是需要积分的，这里给免费的）：

https://github.com/opencv/opencv_3rdparty/tree/ippicv/master_20191018

https://github.com/opencv/opencv_3rdparty/tree/contrib_face_alignment_20170818

https://github.com/opencv/opencv_3rdparty/tree/contrib_xfeatures2d_vgg_20160317

https://github.com/opencv/opencv_3rdparty/tree/contrib_xfeatures2d_boostdesc_20161012