tutorial-matching-keypoint-SIFT.cpp

#include <visp3/core/vpConfig.h>
#include <visp3/gui/vpDisplayOpenCV.h>
#include <visp3/io/vpImageIo.h>
#include <visp3/io/vpVideoReader.h>
#include <visp3/vision/vpKeyPoint.h>
 
int main()
{
#if defined(VISP_HAVE_OPENCV) && defined(HAVE_OPENCV_HIGHGUI) && defined(HAVE_OPENCV_IMGPROC) && \
  (((VISP_HAVE_OPENCV_VERSION < 0x050000)  && defined(HAVE_OPENCV_CALIB3D) && defined(HAVE_OPENCV_FEATURES2D) && defined(HAVE_OPENCV_XFEATURES2D)) || \
   ((VISP_HAVE_OPENCV_VERSION >= 0x050000) && defined(HAVE_OPENCV_3D) && defined(HAVE_OPENCV_FEATURES)))

#ifdef ENABLE_VISP_NAMESPACE
  using namespace VISP_NAMESPACE_NAME;
#endif
  vpImage<unsigned char> I;
 
  vpVideoReader reader;
  reader.setFileName("video-postcard.mp4");
  reader.acquire(I);

  const std::string detectorName = "SIFT";
  const std::string extractorName = "SIFT";
  // Use L2 distance with a matching done using FLANN (Fast Library for
  // Approximate Nearest Neighbors)
  const std::string matcherName = "FlannBased";
  vpKeyPoint::vpFilterMatchingType filterType = vpKeyPoint::ratioDistanceThreshold;
  vpKeyPoint keypoint(detectorName, extractorName, matcherName, filterType);

  std::cout << "Reference keypoints=" << keypoint.buildReference(I) << std::endl;

  vpImage<unsigned char> Idisp;
  Idisp.resize(I.getHeight(), 2 * I.getWidth());
  Idisp.insert(I, vpImagePoint(0, 0));
  Idisp.insert(I, vpImagePoint(0, I.getWidth()));
  vpDisplayOpenCV d(Idisp, 0, 0, "Matching keypoints with SIFT keypoints");
  vpDisplay::display(Idisp);
  vpDisplay::flush(Idisp);
 
  while (!reader.end()) {
    reader.acquire(I);
    Idisp.insert(I, vpImagePoint(0, I.getWidth()));

    vpDisplay::display(Idisp);
    vpDisplay::displayLine(Idisp, vpImagePoint(0, I.getWidth()), vpImagePoint(I.getHeight(), I.getWidth()),
                           vpColor::white, 2);
 
    vpChrono chrono;
    chrono.start();
    unsigned int nbMatch = keypoint.matchPoint(I);
    chrono.stop();
    std::ostringstream oss;
    oss << "Computation time: " << chrono.getDurationMs() << " ms";
    vpDisplay::displayText(Idisp, vpImagePoint(20, 20), oss.str(), vpColor::red);
 
    std::cout << "Matches=" << nbMatch << std::endl;

    vpImagePoint iPref, iPcur;
    for (unsigned int i = 0; i < nbMatch; i++) {
      keypoint.getMatchedPoints(i, iPref, iPcur);
      vpDisplay::displayLine(Idisp, iPref, iPcur + vpImagePoint(0, I.getWidth()), vpColor::green);
    }
    vpDisplay::flush(Idisp);
 
    if (vpDisplay::getClick(Idisp, false))
      break;
  }
 
  vpDisplay::getClick(Idisp);
#endif
 
  return EXIT_SUCCESS;
}