openCV-C++代码，用PCA算法进行人脸主成分提取，并且用kNN算法进行实时表情识别。程序可以自己建立数据库并且进行识别，非常好用！附课程的作业报告。-openCV-C++ code, using PCA algorithm for face principal component extraction and real-time facial expression recognition algorithm with kNN. Program can create their own