OpenCV, feature matching with code from the tutorial

Question

I copied the code of the Feature Matching with FLANN from the OpenCV tutorial page, and made the following changes:

• I used the SIFT features, instead of SURF;

Answer 1

Checkout the matcher_simple.cpp example. It uses a brute force matcher that seems to work pretty well. Here is the code:

// detecting keypoints
SurfFeatureDetector detector(400);
vector keypoints1, keypoints2;
detector.detect(img1, keypoints1);
detector.detect(img2, keypoints2);

// computing descriptors
SurfDescriptorExtractor extractor;
Mat descriptors1, descriptors2;
extractor.compute(img1, keypoints1, descriptors1);
extractor.compute(img2, keypoints2, descriptors2);

// matching descriptors
BFMatcher matcher(NORM_L2);
vector matches;
matcher.match(descriptors1, descriptors2, matches);

// drawing the results
namedWindow("matches", 1);
Mat img_matches;
drawMatches(img1, keypoints1, img2, keypoints2, matches, img_matches);
imshow("matches", img_matches);
waitKey(0);