/* * matching_test.cpp * * Created on: Oct 17, 2010 * Author: ethan */ #include "opencv2/core/core.hpp" #include "opencv2/calib3d/calib3d.hpp" #include "opencv2/features2d/features2d.hpp" #include "opencv2/imgproc/imgproc.hpp" #include "opencv2/highgui/highgui.hpp" #include #include using namespace cv; using namespace std; //Copy (x,y) location of descriptor matches found from KeyPoint data structures into Point2f vectors static void matches2points(const vector& matches, const vector& kpts_train, const vector& kpts_query, vector& pts_train, vector& pts_query) { pts_train.clear(); pts_query.clear(); pts_train.reserve(matches.size()); pts_query.reserve(matches.size()); for (size_t i = 0; i < matches.size(); i++) { const DMatch& match = matches[i]; pts_query.push_back(kpts_query[match.queryIdx].pt); pts_train.push_back(kpts_train[match.trainIdx].pt); } } static double match(const vector& /*kpts_train*/, const vector& /*kpts_query*/, DescriptorMatcher& matcher, const Mat& train, const Mat& query, vector& matches) { double t = (double)getTickCount(); matcher.match(query, train, matches); //Using features2d return ((double)getTickCount() - t) / getTickFrequency(); } static void help() { cout << "This program shows how to use BRIEF descriptor to match points in features2d" << endl << "It takes in two images, finds keypoints and matches them displaying matches and final homography warped results" << endl << "Usage: " << endl << "image1 image2 " << endl << "Example: " << endl << "box.png box_in_scene.png " << endl; } const char* keys = { "{@first_image | box.png | the first image}" "{@second_image | box_in_scene.png | the second image}" }; int main(int argc, const char ** argv) { help(); CommandLineParser parser(argc, argv, keys); string im1_name = parser.get(0); string im2_name = parser.get(1); Mat im1 = imread(im1_name, CV_LOAD_IMAGE_GRAYSCALE); Mat im2 = imread(im2_name, CV_LOAD_IMAGE_GRAYSCALE); if (im1.empty() || im2.empty()) { cout << "could not open one of the images..." << endl; cout << "the cmd parameters have next current value: " << endl; parser.printMessage(); return 1; } double t = (double)getTickCount(); FastFeatureDetector detector(50); BriefDescriptorExtractor extractor(32); //this is really 32 x 8 matches since they are binary matches packed into bytes vector kpts_1, kpts_2; detector.detect(im1, kpts_1); detector.detect(im2, kpts_2); t = ((double)getTickCount() - t) / getTickFrequency(); cout << "found " << kpts_1.size() << " keypoints in " << im1_name << endl << "fount " << kpts_2.size() << " keypoints in " << im2_name << endl << "took " << t << " seconds." << endl; Mat desc_1, desc_2; cout << "computing descriptors..." << endl; t = (double)getTickCount(); extractor.compute(im1, kpts_1, desc_1); extractor.compute(im2, kpts_2, desc_2); t = ((double)getTickCount() - t) / getTickFrequency(); cout << "done computing descriptors... took " << t << " seconds" << endl; //Do matching using features2d cout << "matching with BruteForceMatcher" << endl; BFMatcher matcher_popcount(NORM_HAMMING); vector matches_popcount; double pop_time = match(kpts_1, kpts_2, matcher_popcount, desc_1, desc_2, matches_popcount); cout << "done BruteForceMatcher matching. took " << pop_time << " seconds" << endl; vector mpts_1, mpts_2; matches2points(matches_popcount, kpts_1, kpts_2, mpts_1, mpts_2); //Extract a list of the (x,y) location of the matches vector outlier_mask; Mat H = findHomography(mpts_2, mpts_1, RANSAC, 1, outlier_mask); Mat outimg; drawMatches(im2, kpts_2, im1, kpts_1, matches_popcount, outimg, Scalar::all(-1), Scalar::all(-1), outlier_mask); imshow("matches - popcount - outliers removed", outimg); Mat warped; Mat diff; warpPerspective(im2, warped, H, im1.size()); imshow("warped", warped); absdiff(im1,warped,diff); imshow("diff", diff); waitKey(); return 0; }