#include <opencv2/core.hpp>
#include <opencv2/videoio.hpp>
#include <opencv2/highgui.hpp>
#include <iostream>
using namespace cv;
using namespace std;
int main(int, char**)
{
  Mat frame;
  //--- INITIALIZE VIDEOCAPTURE
  VideoCapture cap;
  // open the default camera using default API
  // cap.open(0);
  // OR advance usage: select any API backend
  int deviceID = 0;             // 0 = open default camera
  int apiID = cv::CAP_ANY;      // 0 = autodetect default API
  // open selected camera using selected API
  cap.open(deviceID, apiID);
  // check if we succeeded
  if (!cap.isOpened()) {
    cerr << "ERROR! Unable to open camera\n";
    return -1;
  }
  //--- GRAB AND WRITE LOOP
  cout << "Start grabbing" << endl
       << "Press any key to terminate" << endl;
  auto smallImage = imread("index.png", -1);
  for (;;)
  {
    // wait for a new frame from camera and store it into 'frame'
    cap.read(frame);
    cv::Rect roi( cv::Point( 50, 50 ), smallImage.size() );
    smallImage.copyTo( frame( roi ) );

    // check if we succeeded
    if (frame.empty()) {
      cerr << "ERROR! blank frame grabbed\n";
      break;
    }
    // show live and wait for a key with timeout long enough to show images
    imshow("Live", frame);
    if (waitKey(5) >= 0)
      break;
  }
  // the camera will be deinitialized automatically in VideoCapture destructor
  return 0;
}