title: How do I use SIFT in OpenCV 3.0 with c++?
body: <p>I have OpenCV 3.0, and I have compiled &amp; installed it with the opencv_contrib module so that's not a problem. Unfortunately the examples from previous versions do not work with the current one, and so although this question has <a href="https://stackoverflow.com/questions/19652812/sift-implementation-in-opencv-2-4-6-ubuntu">already been asked</a> <a href="https://stackoverflow.com/questions/27297706/using-opencv-to-implement-sift-in-image">more than once</a> I would like a more current example that I can actually work with. Even the <a href="http://docs.opencv.org/trunk/doc/tutorials/features2d/table_of_content_features2d/table_of_content_features2d.html#table-of-content-feature2d" rel="nofollow noreferrer">official examples</a> don't work in this version (feature detection works but not other feature examples) and they use SURF anyway.</p>
  
  <p>So, how do I use OpenCV SIFT on C++? I want to grab the keypoints in two images and match them, similar to <a href="http://docs.opencv.org/trunk/doc/tutorials/features2d/feature_flann_matcher/feature_flann_matcher.html#feature-flann-matcher" rel="nofollow noreferrer">this example</a>, but even just getting the points and descriptors would be enough help. Help!</p>