V1 Readme + rangement

ongoing/Visp_tests/matching/tutorial-matching-keypoint-homography.cpp

@@ -0,0 +1,143 @@
+//! \example tutorial-matching-keypoint-homography.cpp
+#include <visp3/core/vpPixelMeterConversion.h>
+#include <visp3/gui/vpDisplayOpenCV.h>
+#include <visp3/io/vpVideoReader.h>
+#include <visp3/vision/vpHomography.h>
+#include <visp3/vision/vpKeyPoint.h>
+
+int main(int argc, const char **argv)
+{
+#if (VISP_HAVE_OPENCV_VERSION >= 0x020101)
+  //! [Select method]
+  int method = 0;
+
+  if (argc > 1)
+    method = atoi(argv[1]);
+
+  if (method == 0)
+    std::cout << "Uses Ransac to estimate the homography" << std::endl;
+  else
+    std::cout << "Uses a robust scheme to estimate the homography" << std::endl;
+  //! [Select method]
+
+  vpImage<unsigned char> I;
+
+  vpVideoReader reader;
+  reader.setFileName("video-postcard.mpeg");
+  reader.acquire(I);
+
+  const std::string detectorName = "ORB";
+  const std::string extractorName = "ORB";
+  // Hamming distance must be used with ORB
+  const std::string matcherName = "BruteForce-Hamming";
+  vpKeyPoint::vpFilterMatchingType filterType = vpKeyPoint::ratioDistanceThreshold;
+  vpKeyPoint keypoint(detectorName, extractorName, matcherName, filterType);
+  keypoint.buildReference(I);
+
+  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, "Homography from matched keypoints");
+  vpDisplay::display(Idisp);
+  vpDisplay::flush(Idisp);
+
+  //! [Set coordinates]
+  vpImagePoint corner_ref[4];
+  corner_ref[0].set_ij(115, 64);
+  corner_ref[1].set_ij(83, 253);
+  corner_ref[2].set_ij(282, 307);
+  corner_ref[3].set_ij(330, 72);
+  //! [Set coordinates]
+  //! [Display]
+  for (unsigned int i = 0; i < 4; i++) {
+    vpDisplay::displayCross(Idisp, corner_ref[i], 12, vpColor::red);
+  }
+  vpDisplay::flush(Idisp);
+  //! [Display]
+
+  //! [Camera]
+  vpCameraParameters cam(840, 840, I.getWidth() / 2, I.getHeight() / 2);
+  //! [Camera]
+
+  vpHomography curHref;
+
+  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);
+
+    //! [Matching]
+    unsigned int nbMatch = keypoint.matchPoint(I);
+    std::cout << "Nb matches: " << nbMatch << std::endl;
+    //! [Matching]
+
+    std::vector<vpImagePoint> iPref(nbMatch),
+        iPcur(nbMatch); // Coordinates in pixels (for display only)
+    //! [Allocation]
+    std::vector<double> mPref_x(nbMatch), mPref_y(nbMatch);
+    std::vector<double> mPcur_x(nbMatch), mPcur_y(nbMatch);
+    std::vector<bool> inliers(nbMatch);
+    //! [Allocation]
+
+    for (unsigned int i = 0; i < nbMatch; i++) {
+      keypoint.getMatchedPoints(i, iPref[i], iPcur[i]);
+      //! [Pixel conversion]
+      vpPixelMeterConversion::convertPoint(cam, iPref[i], mPref_x[i], mPref_y[i]);
+      vpPixelMeterConversion::convertPoint(cam, iPcur[i], mPcur_x[i], mPcur_y[i]);
+      //! [Pixel conversion]
+    }
+
+    //! [Homography estimation]
+    try {
+      double residual;
+      if (method == 0)
+        vpHomography::ransac(mPref_x, mPref_y, mPcur_x, mPcur_y, curHref, inliers, residual,
+                             (unsigned int)(mPref_x.size() * 0.25), 2.0 / cam.get_px(), true);
+      else
+        vpHomography::robust(mPref_x, mPref_y, mPcur_x, mPcur_y, curHref, inliers, residual, 0.4, 4, true);
+    } catch (...) {
+      std::cout << "Cannot compute homography from matches..." << std::endl;
+    }
+
+    //! [Homography estimation]
+
+    //! [Projection]
+    vpImagePoint corner_cur[4];
+    for (int i = 0; i < 4; i++) {
+      corner_cur[i] = vpHomography::project(cam, curHref, corner_ref[i]);
+    }
+    //! [Projection]
+
+    //! [Display contour]
+    vpImagePoint offset(0, I.getWidth());
+    for (int i = 0; i < 4; i++) {
+      vpDisplay::displayLine(Idisp, corner_cur[i] + offset, corner_cur[(i + 1) % 4] + offset, vpColor::blue, 3);
+    }
+    //! [Display contour]
+
+    //! [Display matches]
+    for (unsigned int i = 0; i < nbMatch; i++) {
+      if (inliers[i] == true)
+        vpDisplay::displayLine(Idisp, iPref[i], iPcur[i] + offset, vpColor::green);
+      else
+        vpDisplay::displayLine(Idisp, iPref[i], iPcur[i] + offset, vpColor::red);
+    }
+    //! [Display matches]
+
+    vpDisplay::flush(Idisp);
+
+    if (vpDisplay::getClick(Idisp, false))
+      break;
+  }
+
+  vpDisplay::getClick(Idisp);
+#else
+  (void)argc;
+  (void)argv;
+#endif
+  return 0;
+}