本程序用到了opencv 中的扩展库opencv contrib, 先用take.cpp来获取自己的数据库，然后在用tria.cpp来训练能检测自己的脸的检测器，再运行recon.cpp来进行人脸检测。(This program uses the extension library opencv contrib in OpenCV. First, take.cpp is used to get its own database, then tria.cpp is used to train the detector to detect its face, then run recon.cpp to detect the face.)