tutorial-matching-keypoint-SIFT.cpp

#include <visp3/gui/vpDisplayOpenCV.h>
#include <visp3/io/vpVideoReader.h>
#include <visp3/io/vpImageIo.h>
#include <visp3/vision/vpKeyPoint.h>

int main() {
#if (VISP_HAVE_OPENCV_VERSION >= 0x020101) && (defined(VISP_HAVE_OPENCV_NONFREE) || defined(VISP_HAVE_OPENCV_XFEATURES2D))
  vpImage<unsigned char> I;

  vpVideoReader reader;
  reader.setFileName("video-postcard.mpeg");
  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);

    unsigned int nbMatch = keypoint.matchPoint(I);

    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 0;
}