Code tutorial

samples/cpp/tutorial_code/calib3d/real_time_pose_estimation/src/RobustMatcher.cpp

+/*
+ * RobustMatcher.cpp
+ *
+ *  Created on: Jun 4, 2014
+ *      Author: eriba
+ */
+
+#include "RobustMatcher.h"
+#include <time.h>
+
+#include <opencv2/features2d/features2d.hpp>
+
+RobustMatcher::~RobustMatcher()
+{
+  // TODO Auto-generated destructor stub
+}
+
+void RobustMatcher::computeKeyPoints( const cv::Mat& image, std::vector<cv::KeyPoint>& keypoints)
+{
+  detector_->detect(image, keypoints);
+}
+
+void RobustMatcher::computeDescriptors( const cv::Mat& image, std::vector<cv::KeyPoint>& keypoints, cv::Mat& descriptors)
+{
+  extractor_->compute(image, keypoints, descriptors);
+}
+
+int RobustMatcher::ratioTest(std::vector<std::vector<cv::DMatch> > &matches)
+{
+  int removed = 0;
+  // for all matches
+  for ( std::vector<std::vector<cv::DMatch> >::iterator
+        matchIterator= matches.begin(); matchIterator!= matches.end(); ++matchIterator)
+  {
+    // if 2 NN has been identified
+    if (matchIterator->size() > 1)
+    {
+      // check distance ratio
+      if ((*matchIterator)[0].distance / (*matchIterator)[1].distance > ratio_)
+      {
+        matchIterator->clear(); // remove match
+        removed++;
+      }
+    }
+    else
+    { // does not have 2 neighbours
+      matchIterator->clear(); // remove match
+      removed++;
+    }
+  }
+  return removed;
+}
+
+void RobustMatcher::symmetryTest( const std::vector<std::vector<cv::DMatch> >& matches1,
+                     const std::vector<std::vector<cv::DMatch> >& matches2,
+                     std::vector<cv::DMatch>& symMatches )
+{
+
+  // for all matches image 1 -> image 2
+   for (std::vector<std::vector<cv::DMatch> >::const_iterator
+       matchIterator1 = matches1.begin(); matchIterator1 != matches1.end(); ++matchIterator1)
+   {
+
+      // ignore deleted matches
+      if (matchIterator1->empty() || matchIterator1->size() < 2)
+         continue;
+
+      // for all matches image 2 -> image 1
+      for (std::vector<std::vector<cv::DMatch> >::const_iterator
+          matchIterator2 = matches2.begin(); matchIterator2 != matches2.end(); ++matchIterator2)
+      {
+        // ignore deleted matches
+        if (matchIterator2->empty() || matchIterator2->size() < 2)
+           continue;
+
+        // Match symmetry test
+        if ((*matchIterator1)[0].queryIdx ==
+            (*matchIterator2)[0].trainIdx &&
+            (*matchIterator2)[0].queryIdx ==
+            (*matchIterator1)[0].trainIdx)
+        {
+            // add symmetrical match
+            symMatches.push_back(
+              cv::DMatch((*matchIterator1)[0].queryIdx,
+                         (*matchIterator1)[0].trainIdx,
+                         (*matchIterator1)[0].distance));
+            break; // next match in image 1 -> image 2
+        }
+      }
+   }
+
+}
+
+void RobustMatcher::robustMatch( const cv::Mat& frame, std::vector<cv::DMatch>& good_matches,
+              std::vector<cv::KeyPoint>& keypoints_frame, const cv::Mat& descriptors_model )
+{
+
+  // 1a. Detection of the ORB features
+  this->computeKeyPoints(frame, keypoints_frame);
+
+  // 1b. Extraction of the ORB descriptors
+  cv::Mat descriptors_frame;
+  this->computeDescriptors(frame, keypoints_frame, descriptors_frame);
+
+  // 2. Match the two image descriptors
+  std::vector<std::vector<cv::DMatch> > matches12, matches21;
+
+  // 2a. From image 1 to image 2
+  matcher_->knnMatch(descriptors_frame, descriptors_model, matches12, 2); // return 2 nearest neighbours
+
+  // 2b. From image 2 to image 1
+  matcher_->knnMatch(descriptors_model, descriptors_frame, matches21, 2); // return 2 nearest neighbours
+
+  // 3. Remove matches for which NN ratio is > than threshold
+  // clean image 1 -> image 2 matches
+  int removed1 = ratioTest(matches12);
+  // clean image 2 -> image 1 matches
+  int removed2 = ratioTest(matches21);
+
+  // 4. Remove non-symmetrical matches
+  symmetryTest(matches12, matches21, good_matches);
+
+}
+
+void RobustMatcher::fastRobustMatch( const cv::Mat& frame, std::vector<cv::DMatch>& good_matches,
+                                 std::vector<cv::KeyPoint>& keypoints_frame,
+                                 const cv::Mat& descriptors_model )
+{
+  good_matches.clear();
+
+  // 1a. Detection of the ORB features
+  this->computeKeyPoints(frame, keypoints_frame);
+
+  // 1b. Extraction of the ORB descriptors
+  cv::Mat descriptors_frame;
+  this->computeDescriptors(frame, keypoints_frame, descriptors_frame);
+
+  // 2. Match the two image descriptors
+  std::vector<std::vector<cv::DMatch> > matches;
+  matcher_->knnMatch(descriptors_frame, descriptors_model, matches, 2);
+
+  // 3. Remove matches for which NN ratio is > than threshold
+  int removed = ratioTest(matches);
+
+  // 4. Fill good matches container
+  for ( std::vector<std::vector<cv::DMatch> >::iterator
+         matchIterator= matches.begin(); matchIterator!= matches.end(); ++matchIterator)
+  {
+    if (!matchIterator->empty()) good_matches.push_back((*matchIterator)[0]);
+  }
+
+}