Example: hwdrivers_camera_capture_dialog

C++ example source code:

/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2024, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */

#include <mrpt/gui/CDisplayWindow.h>
#include <mrpt/hwdrivers/CCameraSensor.h>
#include <mrpt/img/CImage.h>
#include <mrpt/system/CTicTac.h>

#include <chrono>
#include <iostream>
#include <thread>

using namespace mrpt;
using namespace mrpt::gui;
using namespace mrpt::obs;
using namespace mrpt::hwdrivers;
using namespace mrpt::img;
using namespace std;

// ------------------------------------------------------
//              TestCameraCaptureAsk
// ------------------------------------------------------
void TestCameraCaptureAsk()
{
  CCameraSensor::Ptr cam = prepareVideoSourceFromUserSelection();

  if (!cam)
  {
    cerr << "The user didn't pick any camera. Exiting." << endl;
    return;
  }

  CDisplayWindow win("Live video");

  cout << "Press 's' to save frames.\nClose the window to exit.\n";

  double counter = 0;
  mrpt::system::CTicTac tictac;

  while (win.isOpen())
  {
    if (!counter) tictac.Tic();

    mrpt::obs::CObservation::Ptr obs = cam->getNextFrame();
    ASSERT_(obs);

    CImage* img = nullptr;

    if (IS_CLASS(*obs, CObservationImage))
    {
      CObservationImage::Ptr o = std::dynamic_pointer_cast<CObservationImage>(obs);
      img = &o->image;
    }
    else if (IS_CLASS(*obs, CObservationStereoImages))
    {
      CObservationStereoImages::Ptr o = std::dynamic_pointer_cast<CObservationStereoImages>(obs);
      img = &o->imageRight;
    }
    else if (IS_CLASS(*obs, CObservation3DRangeScan))
    {
      CObservation3DRangeScan::Ptr o = std::dynamic_pointer_cast<CObservation3DRangeScan>(obs);
      if (o->hasIntensityImage) img = &o->intensityImage;
    }

    if (img) win.showImage(*img);

    if (++counter == 10)
    {
      double t = tictac.Tac();
      cout << "Frame Rate: " << counter / t << " fps" << endl;
      counter = 0;
    }

    // Process keystrokes:
    if (mrpt::system::os::kbhit())
    {
      const int key_code = mrpt::system::os::getch();
      switch (key_code)
      {
        case 's':
        case 'S':
        {
          static int cnt = 0;
          const std::string sFile = mrpt::format("frame%05i.png", cnt++);
          cout << "Saving frame to: " << sFile << endl;
          bool savedOk = img->saveToFile(sFile);
          ASSERT_(savedOk);
        }
        break;
        default:
          break;
      };
    }

    std::this_thread::sleep_for(2ms);
  }

  cout << "Closing..." << endl;
}

// ------------------------------------------------------
//                      MAIN
// ------------------------------------------------------
int main()
{
  try
  {
    TestCameraCaptureAsk();

    return 0;
  }
  catch (const std::exception& e)
  {
    std::cerr << "MRPT error: " << mrpt::exception_to_str(e) << std::endl;
    return -1;
  }
}