Visual Servoing Platform  version 3.3.0 under development (2020-02-17)
tutorial-export-image.cpp
#include <visp3/io/vpImageIo.h>
#include <visp3/gui/vpDisplayX.h>
#include <visp3/gui/vpDisplayGTK.h>
#include <visp3/gui/vpDisplayGDI.h>
#include <visp3/gui/vpDisplayD3D.h>
#include <visp3/gui/vpDisplayOpenCV.h>
int main()
{
vpImage<unsigned char> I(240, 320, 255); // Create a black grey level image
vpImage<vpRGBa> Ioverlay;
// Depending on the detected third party libraries, we instantiate here the
// first video device which is available
#if defined(VISP_HAVE_X11)
#elif defined(VISP_HAVE_GTK)
#elif defined(VISP_HAVE_GDI)
#elif defined(VISP_HAVE_D3D9)
#elif defined(VISP_HAVE_OPENCV)
#endif
// Initialize the display with the image I. Display and image are
// now link together.
#ifdef VISP_HAVE_DISPLAY
d->init(I);
#endif
// Set the display background with image I content
// Draw a red rectangle in the display overlay (foreground)
vpDisplay::displayRectangle(I, 10, 10, 100, 20, vpColor::red, true);
// Flush the foreground and background display
// Updates the color image with the original loaded image and the overlay
vpDisplay::getImage(I, Ioverlay) ;
// Write the color image on the disk
std::cout << "Save image in overlay.ppm" << std::endl;
std::string ofilename("overlay.png");
vpImageIo::write(Ioverlay, ofilename) ;
// Wait for a click in the display window
std::cout << "A click to quit..." << std::endl;
#ifdef VISP_HAVE_DISPLAY
delete d;
#endif
}