1 #include <opencv2/features2d.hpp>
2 #include <opencv2/imgcodecs.hpp>
3 #include <opencv2/opencv.hpp>
4 #include <vector>
5 #include <iostream>
6
7 using namespace std;
8 using namespace cv;
9
10 const float inlier_threshold = 2.5f; // Distance threshold to identify inliers
11 const float nn_match_ratio = 0.8f; // Nearest neighbor matching ratio
12
main(void)13 int main(void)
14 {
15 Mat img1 = imread("../data/graf1.png", IMREAD_GRAYSCALE);
16 Mat img2 = imread("../data/graf3.png", IMREAD_GRAYSCALE);
17
18 Mat homography;
19 FileStorage fs("../data/H1to3p.xml", FileStorage::READ);
20 fs.getFirstTopLevelNode() >> homography;
21
22 vector<KeyPoint> kpts1, kpts2;
23 Mat desc1, desc2;
24
25 Ptr<AKAZE> akaze = AKAZE::create();
26 akaze->detectAndCompute(img1, noArray(), kpts1, desc1);
27 akaze->detectAndCompute(img2, noArray(), kpts2, desc2);
28
29 BFMatcher matcher(NORM_HAMMING);
30 vector< vector<DMatch> > nn_matches;
31 matcher.knnMatch(desc1, desc2, nn_matches, 2);
32
33 vector<KeyPoint> matched1, matched2, inliers1, inliers2;
34 vector<DMatch> good_matches;
35 for(size_t i = 0; i < nn_matches.size(); i++) {
36 DMatch first = nn_matches[i][0];
37 float dist1 = nn_matches[i][0].distance;
38 float dist2 = nn_matches[i][1].distance;
39
40 if(dist1 < nn_match_ratio * dist2) {
41 matched1.push_back(kpts1[first.queryIdx]);
42 matched2.push_back(kpts2[first.trainIdx]);
43 }
44 }
45
46 for(unsigned i = 0; i < matched1.size(); i++) {
47 Mat col = Mat::ones(3, 1, CV_64F);
48 col.at<double>(0) = matched1[i].pt.x;
49 col.at<double>(1) = matched1[i].pt.y;
50
51 col = homography * col;
52 col /= col.at<double>(2);
53 double dist = sqrt( pow(col.at<double>(0) - matched2[i].pt.x, 2) +
54 pow(col.at<double>(1) - matched2[i].pt.y, 2));
55
56 if(dist < inlier_threshold) {
57 int new_i = static_cast<int>(inliers1.size());
58 inliers1.push_back(matched1[i]);
59 inliers2.push_back(matched2[i]);
60 good_matches.push_back(DMatch(new_i, new_i, 0));
61 }
62 }
63
64 Mat res;
65 drawMatches(img1, inliers1, img2, inliers2, good_matches, res);
66 imwrite("res.png", res);
67
68 double inlier_ratio = inliers1.size() * 1.0 / matched1.size();
69 cout << "A-KAZE Matching Results" << endl;
70 cout << "*******************************" << endl;
71 cout << "# Keypoints 1: \t" << kpts1.size() << endl;
72 cout << "# Keypoints 2: \t" << kpts2.size() << endl;
73 cout << "# Matches: \t" << matched1.size() << endl;
74 cout << "# Inliers: \t" << inliers1.size() << endl;
75 cout << "# Inliers Ratio: \t" << inlier_ratio << endl;
76 cout << endl;
77
78 return 0;
79 }
80
