1 #include <opencv2/features2d.hpp>
2 #include <opencv2/videoio.hpp>
3 #include <opencv2/opencv.hpp>
8 #include "stats.h" // Stats structure definition
9 #include "utils.h" // Drawing and printing functions
14 const double akaze_thresh = 3e-4; // AKAZE detection threshold set to locate about 1000 keypoints
15 const double ransac_thresh = 2.5f; // RANSAC inlier threshold
16 const double nn_match_ratio = 0.8f; // Nearest-neighbour matching ratio
17 const int bb_min_inliers = 100; // Minimal number of inliers to draw bounding box
18 const int stats_update_period = 10; // On-screen statistics are updated every 10 frames
23 Tracker(Ptr<Feature2D> _detector, Ptr<DescriptorMatcher> _matcher) :
28 void setFirstFrame(const Mat frame, vector<Point2f> bb, string title, Stats& stats);
29 Mat process(const Mat frame, Stats& stats);
30 Ptr<Feature2D> getDetector() {
34 Ptr<Feature2D> detector;
35 Ptr<DescriptorMatcher> matcher;
36 Mat first_frame, first_desc;
37 vector<KeyPoint> first_kp;
38 vector<Point2f> object_bb;
41 void Tracker::setFirstFrame(const Mat frame, vector<Point2f> bb, string title, Stats& stats)
43 first_frame = frame.clone();
44 (*detector)(first_frame, noArray(), first_kp, first_desc);
45 stats.keypoints = (int)first_kp.size();
46 drawBoundingBox(first_frame, bb);
47 putText(first_frame, title, Point(0, 60), FONT_HERSHEY_PLAIN, 5, Scalar::all(0), 4);
51 Mat Tracker::process(const Mat frame, Stats& stats)
55 (*detector)(frame, noArray(), kp, desc);
56 stats.keypoints = (int)kp.size();
58 vector< vector<DMatch> > matches;
59 vector<KeyPoint> matched1, matched2;
60 matcher->knnMatch(first_desc, desc, matches, 2);
61 for(unsigned i = 0; i < matches.size(); i++) {
62 if(matches[i][0].distance < nn_match_ratio * matches[i][1].distance) {
63 matched1.push_back(first_kp[matches[i][0].queryIdx]);
64 matched2.push_back( kp[matches[i][0].trainIdx]);
67 stats.matches = (int)matched1.size();
69 Mat inlier_mask, homography;
70 vector<KeyPoint> inliers1, inliers2;
71 vector<DMatch> inlier_matches;
72 if(matched1.size() >= 4) {
73 homography = findHomography(Points(matched1), Points(matched2),
74 RANSAC, ransac_thresh, inlier_mask);
77 if(matched1.size() < 4 || homography.empty()) {
79 hconcat(first_frame, frame, res);
84 for(unsigned i = 0; i < matched1.size(); i++) {
85 if(inlier_mask.at<uchar>(i)) {
86 int new_i = static_cast<int>(inliers1.size());
87 inliers1.push_back(matched1[i]);
88 inliers2.push_back(matched2[i]);
89 inlier_matches.push_back(DMatch(new_i, new_i, 0));
92 stats.inliers = (int)inliers1.size();
93 stats.ratio = stats.inliers * 1.0 / stats.matches;
95 vector<Point2f> new_bb;
96 perspectiveTransform(object_bb, new_bb, homography);
97 Mat frame_with_bb = frame.clone();
98 if(stats.inliers >= bb_min_inliers) {
99 drawBoundingBox(frame_with_bb, new_bb);
102 drawMatches(first_frame, inliers1, frame_with_bb, inliers2,
104 Scalar(255, 0, 0), Scalar(255, 0, 0));
108 int main(int argc, char **argv)
111 cerr << "Usage: " << endl <<
112 "akaze_track input_path output_path bounding_box" << endl;
115 VideoCapture video_in(argv[1]);
116 VideoWriter video_out(argv[2],
117 (int)video_in.get(CAP_PROP_FOURCC),
118 (int)video_in.get(CAP_PROP_FPS),
119 Size(2 * (int)video_in.get(CAP_PROP_FRAME_WIDTH),
120 2 * (int)video_in.get(CAP_PROP_FRAME_HEIGHT)));
122 if(!video_in.isOpened()) {
123 cerr << "Couldn't open " << argv[1] << endl;
126 if(!video_out.isOpened()) {
127 cerr << "Couldn't open " << argv[2] << endl;
132 FileStorage fs(argv[3], FileStorage::READ);
133 if(fs["bounding_box"].empty()) {
134 cerr << "Couldn't read bounding_box from " << argv[3] << endl;
137 fs["bounding_box"] >> bb;
138 Ptr<Feature2D> akaze = Feature2D::create("AKAZE");
139 akaze->set("threshold", akaze_thresh);
140 Ptr<Feature2D> orb = Feature2D::create("ORB");
141 Ptr<DescriptorMatcher> matcher = DescriptorMatcher::create("BruteForce-Hamming");
142 Tracker akaze_tracker(akaze, matcher);
143 Tracker orb_tracker(orb, matcher);
145 Stats stats, akaze_stats, orb_stats;
148 akaze_tracker.setFirstFrame(frame, bb, "AKAZE", stats);
149 orb_tracker.getDetector()->set("nFeatures", stats.keypoints);
150 orb_tracker.setFirstFrame(frame, bb, "ORB", stats);
152 Stats akaze_draw_stats, orb_draw_stats;
153 int frame_count = (int)video_in.get(CAP_PROP_FRAME_COUNT);
154 Mat akaze_res, orb_res, res_frame;
155 for(int i = 1; i < frame_count; i++) {
156 bool update_stats = (i % stats_update_period == 0);
159 akaze_res = akaze_tracker.process(frame, stats);
160 akaze_stats += stats;
162 akaze_draw_stats = stats;
165 orb_tracker.getDetector()->set("nFeatures", stats.keypoints);
166 orb_res = orb_tracker.process(frame, stats);
169 orb_draw_stats = stats;
172 drawStatistics(akaze_res, akaze_draw_stats);
173 drawStatistics(orb_res, orb_draw_stats);
174 vconcat(akaze_res, orb_res, res_frame);
175 video_out << res_frame;
176 cout << i << "/" << frame_count - 1 << endl;
178 akaze_stats /= frame_count - 1;
179 orb_stats /= frame_count - 1;
180 printStatistics("AKAZE", akaze_stats);
181 printStatistics("ORB", orb_stats);