diff --git a/samples/cpp/tutorial_code/xfeatures2D/LATCH_match.cpp b/samples/cpp/tutorial_code/xfeatures2D/LATCH_match.cpp new file mode 100644 index 0000000000..a9413b871b --- /dev/null +++ b/samples/cpp/tutorial_code/xfeatures2D/LATCH_match.cpp @@ -0,0 +1,92 @@ +#include +#include +#include +#include +#include +#include + +// If you find this code useful, please add a reference to the following paper in your work: +// Gil Levi and Tal Hassner, "LATCH: Learned Arrangements of Three Patch Codes", arXiv preprint arXiv:1501.03719, 15 Jan. 2015 + +using namespace std; +using namespace cv; + +const float inlier_threshold = 2.5f; // Distance threshold to identify inliers +const float nn_match_ratio = 0.8f; // Nearest neighbor matching ratio + +int main(void) +{ + Mat img1 = imread("../data/graf1.png", IMREAD_GRAYSCALE); + Mat img2 = imread("../data/graf3.png", IMREAD_GRAYSCALE); + + + Mat homography; + FileStorage fs("../data/H1to3p.xml", FileStorage::READ); + + fs.getFirstTopLevelNode() >> homography; + + vector kpts1, kpts2; + Mat desc1, desc2; + + Ptr orb_detector = cv::ORB::create(10000); + + Ptr latch = xfeatures2d::LATCH::create(); + + + orb_detector->detect(img1, kpts1); + latch->compute(img1, kpts1, desc1); + + orb_detector->detect(img2, kpts2); + latch->compute(img2, kpts2, desc2); + + BFMatcher matcher(NORM_HAMMING); + vector< vector > nn_matches; + matcher.knnMatch(desc1, desc2, nn_matches, 2); + + vector matched1, matched2, inliers1, inliers2; + vector good_matches; + for (size_t i = 0; i < nn_matches.size(); i++) { + DMatch first = nn_matches[i][0]; + float dist1 = nn_matches[i][0].distance; + float dist2 = nn_matches[i][1].distance; + + if (dist1 < nn_match_ratio * dist2) { + matched1.push_back(kpts1[first.queryIdx]); + matched2.push_back(kpts2[first.trainIdx]); + } + } + + for (unsigned i = 0; i < matched1.size(); i++) { + Mat col = Mat::ones(3, 1, CV_64F); + col.at(0) = matched1[i].pt.x; + col.at(1) = matched1[i].pt.y; + + col = homography * col; + col /= col.at(2); + double dist = sqrt(pow(col.at(0) - matched2[i].pt.x, 2) + + pow(col.at(1) - matched2[i].pt.y, 2)); + + if (dist < inlier_threshold) { + int new_i = static_cast(inliers1.size()); + inliers1.push_back(matched1[i]); + inliers2.push_back(matched2[i]); + good_matches.push_back(DMatch(new_i, new_i, 0)); + } + } + + Mat res; + drawMatches(img1, inliers1, img2, inliers2, good_matches, res); + imwrite("../../samples/data/latch_res.png", res); + + + double inlier_ratio = inliers1.size() * 1.0 / matched1.size(); + cout << "LATCH Matching Results" << endl; + cout << "*******************************" << endl; + cout << "# Keypoints 1: \t" << kpts1.size() << endl; + cout << "# Keypoints 2: \t" << kpts2.size() << endl; + cout << "# Matches: \t" << matched1.size() << endl; + cout << "# Inliers: \t" << inliers1.size() << endl; + cout << "# Inliers Ratio: \t" << inlier_ratio << endl; + cout << endl; + return 0; +}