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Carole's profile - activity

2016-04-13 07:52:53 -0600 received badge  Necromancer (source)
2016-04-13 05:28:38 -0600 answered a question How can I get keypoints for given location in MATLAB

I know it's an old post, but I just had the same issue. So just in case someone else run into the same problem! You can do something like this :


image = imread('image.jpg');
points2f=[10 20;30 40;50 60]
keypoints=cv.KeyPointsFilter.convertFromPoints(points2f,'Size',2)
extractor = cv.DescriptorExtractor('BRIEF');
descriptors = extractor.compute(image, keypoints);

However the problem is OpenCV won't reestimate your angle or scale you provide. By default an angle of -1 is given (meaning you did not give any angle) If someone else tries to find the same answer but for 'SIFT', I would recommend using vl_feat in matlab with :

Coordinates=[10 20;30 40;50 60]
frames=Coordinates;
frames(3,:)=scale;
[F,D] = vl_covdet(image,'frames',frames,'estimateAffineShape', true,'estimateOrientation', true) ;

This way, the angle is reestimated (but not the scale...)