注意CV::Mat dst(height,weight)顺序
cv::Mat background;
cap.read(background);
cv::Mat dst(720,1280,CV_8UC3,cv::Scalar(0));
cv::Rect rect_face(0,0,640,720);
cv::resize(tmp_ptr->frame,tmp_ptr->frame,cv::Size(rect_face.width,rect_face.height));
cv::imwrite("videos/test/"+std::to_string(h)+"_tmp_ptr.jpg",tmp_ptr->frame);
tmp_ptr->frame.copyTo(dst(rect_face));
cv::imwrite("videos/test/"+std::to_string(h)+"_tmp_ptr_.jpg",dst);
cv::Rect rect_background(640,0,640,720);
cv::resize(background,background,cv::Size(rect_background.width,rect_background.height));
cv::imwrite("videos/test/"+std::to_string(h)+"_background.jpg",background);
background.copyTo(dst(rect_background));
cv::imwrite("videos/test/"+std::to_string(h)+".jpg",dst);