Efficient way for SIFT descriptor matching

Question

There are 2 images A and B. I extract the keypoints (a[i] and b[i]) from them.
I wonder how can I determine the matching between a[i] and b[j], efficiently?

The ob

Answer 1

KD tree stores the trained descriptors in a way that it is really faster to find the most similar descriptor when performing the matching.

With OpenCV it is really easy to use kd-tree, I will give you an example for the flann matcher:

flann::GenericIndex< cvflann::L2 >  *tree; // the flann searching tree
tree = new flann::GenericIndex< cvflann::L2 >(descriptors, cvflann::KDTreeIndexParams(4)); // a 4 k-d tree

Then, when you do the matching:

const cvflann::SearchParams params(32);
tree.knnSearch(queryDescriptors, indices, dists, 2, cvflann::SearchParams(8));