ExampleOpenCVCam.cpp

Example for capturing images using OpenCV.

Author

esquivel (adapted from OpenCV examples)

Date

05/2013

/*
  This file is part of the BIAS library (Basic ImageAlgorithmS).

  Copyright (C) 2003-2009    (see file CONTACT for details)
  Multimediale Systeme der Informationsverarbeitung
  Institut fuer Informatik
  Christian-Albrechts-Universitaet Kiel


  BIAS is free software; you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  BIAS is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with BIAS; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

/** @example ExampleOpenCVCam.cpp
    @ingroup g_examples
    @ingroup g_videosource
    @brief   Example for capturing images using OpenCV.
    @author  esquivel (adapted from OpenCV examples)
    @date    05/2013
*/

#include "cv.h" 
#include "highgui.h" 
#include <iostream>
#include <vector>

using namespace std;

int main(int argc, char *argv[])
{
  // Read camera IDs from command line
  int numCams = 1;
  std::vector<int> camIDs(1, CV_CAP_ANY);
  if (argc > 1) {
    numCams = argc - 1;
    camIDs.resize(numCams);
    for (int i = 0; i < numCams; i++)
      camIDs[i] = atoi(argv[i+1]);
  }
  
  // Create capture devices
  std::vector<CvCapture*> camDevs(numCams, NULL);
  for (int i = 0; i < numCams; i++) {
    camDevs[i] = cvCaptureFromCAM(camIDs[i]);
    if (!camDevs[i]) {
      cout << "Failed to create capture device for ID " << camIDs[i] << endl;
      return -1;
    } else {
      cout << "Created capture device for ID " << camIDs[i] << endl;
    }
  }
  
  // Create window to display the captured camera images
  cvNamedWindow("ExampleOpenCVCam", CV_WINDOW_AUTOSIZE);
  
  // Show captured camera images and repeat
  int currentID = 0;
  bool isRunning = true;
  std::vector<IplImage*> frames(numCams, NULL);
  while (isRunning)
  {
    // Get frames
    for (int i = 0; i < numCams; i++)
      frames[i] = cvQueryFrame(camDevs[i]);

    // Show current camera's frame
    if (!frames[currentID]) {
      cout << "Captured frame is empty!" << endl;
      isRunning = false;
    } else {
      cvShowImage("ExampleOpenCVCam", frames[currentID]);
      int key = cvWaitKey(10) & 255;
      if (key == 27)
        isRunning = false;
      else if (key == 13)
        currentID = (currentID + 1) % numCams;
      else if (key == 8)
        currentID = (currentID + numCams - 1) % numCams;
    }
  }
  
  // Release capture devices
  cout << "Release capture devices and quit" << endl;
  for (int i = 0; i < numCams; i++)
    cvReleaseCapture(&camDevs[i]);
  cvDestroyWindow("ExampleOpenCVCam");
  
  return 0;
}