编译命令：
g++ main.cpp -std=c++11 -I/usr/local/include/opencv -I/usr/local/include -L/usr/local/lib -lopencv_stitching -lopencv_objdetect -lopencv_superres -lopencv_videostab -lopencv_calib3d -lopencv_features2d -lopencv_highgui -lopencv_photo -lopencv_ml -lopencv_imgproc -lopencv_flann -lopencv_core -ldl -Wl,-rpath,. -o test