title: Implementations of image matching using "Scalable Recognition with a Vocabulary Tree"
body: <p>Do you know of any implementations or improvements of the method of matching images proposed by David Nister and Henrik Stewenius, called "<a href="http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.61.9520&amp;rep=rep1&amp;type=pdf" rel="noreferrer">Scalable Recognition with a Vocabulary Tree</a>"? I am trying to implement it and I am having trouble understanding some parts of the algorithm (more specifically, computing the score).</p>