Visual Servoing Platform  version 3.5.1 under development (2023-06-19)
grabOpenCV.cpp

Example of framegrabbing using OpenCV cv::VideoCapture class.

/****************************************************************************
*
* ViSP, open source Visual Servoing Platform software.
* Copyright (C) 2005 - 2019 by Inria. All rights reserved.
*
* This software is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
* See the file LICENSE.txt at the root directory of this source
* distribution for additional information about the GNU GPL.
*
* For using ViSP with software that can not be combined with the GNU
* GPL, please contact Inria about acquiring a ViSP Professional
* Edition License.
*
* See http://visp.inria.fr for more information.
*
* This software was developed at:
* Inria Rennes - Bretagne Atlantique
* Campus Universitaire de Beaulieu
* 35042 Rennes Cedex
* France
*
* If you have questions regarding the use of this file, please contact
* Inria at visp@inria.fr
*
* This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
* WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* Description:
* Acquire images using OpenCV cv::VideoCapture.
*
* Authors:
* Fabien Spindler
*
*****************************************************************************/
#include <iostream>
#include <visp3/core/vpConfig.h>
#if defined(VISP_HAVE_OPENCV) && (VISP_HAVE_OPENCV_VERSION >= 0x020100)
#include <visp3/core/vpImage.h>
#include <visp3/core/vpImageConvert.h>
#include <visp3/gui/vpDisplayOpenCV.h>
#include <visp3/sensor/vpOpenCVGrabber.h>
// usage: binary <device name>
// device name: 0 is the default to dial with the first camera,
// 1 to dial with a second camera attached to the computer
int main(int argc, char **argv)
{
try {
int device = 0;
if (argc > 1)
device = atoi(argv[1]);
std::cout << "Use device: " << device << std::endl;
cv::VideoCapture cap(device); // open the default camera
#if (VISP_HAVE_OPENCV_VERSION >= 0x030000)
cap.set(cv::CAP_PROP_FRAME_WIDTH, 640);
cap.set(cv::CAP_PROP_FRAME_HEIGHT, 480);
#else
cap.set(CV_CAP_PROP_FRAME_WIDTH, 640);
cap.set(CV_CAP_PROP_FRAME_HEIGHT, 480);
#endif
if (!cap.isOpened()) // check if we succeeded
return EXIT_FAILURE;
cv::Mat frame;
int i = 0;
while ((i++ < 100) && !cap.read(frame)) {
}; // warm up camera by skiping unread frames
std::cout << "Image size: "
#if (VISP_HAVE_OPENCV_VERSION >= 0x030000)
<< (int)cap.get(cv::CAP_PROP_FRAME_WIDTH) << " " << (int)cap.get(cv::CAP_PROP_FRAME_HEIGHT) << std::endl;
#else
<< (int)cap.get(CV_CAP_PROP_FRAME_WIDTH) << " " << (int)cap.get(CV_CAP_PROP_FRAME_HEIGHT) << std::endl;
#endif
// vpImage<vpRGBa> I; // for color images
vpImage<unsigned char> I; // for gray images
for (;;) {
cap >> frame; // get a new frame from camera
// Convert the image in ViSP format and display it
if (vpDisplay::getClick(I, false)) // a click to exit
break;
}
// the camera will be deinitialized automatically in VideoCapture
// destructor
return EXIT_SUCCESS;
} catch (const vpException &e) {
std::cout << "Catch an exception: " << e << std::endl;
return EXIT_FAILURE;
}
}
#else
int main()
{
std::cout << "You do not have OpenCV functionalities to display images..." << std::endl;
std::cout << "Tip:" << std::endl;
std::cout << "- Install OpenCV, configure again ViSP using cmake and build again this example" << std::endl;
return EXIT_SUCCESS;
}
#endif
The vpDisplayOpenCV allows to display image using the OpenCV library. Thus to enable this class OpenC...
static bool getClick(const vpImage< unsigned char > &I, bool blocking=true)
static void display(const vpImage< unsigned char > &I)
static void flush(const vpImage< unsigned char > &I)
error that can be emited by ViSP classes.
Definition: vpException.h:72
static void convert(const vpImage< unsigned char > &src, vpImage< vpRGBa > &dest)