Re: Small number of ORB features between similar frames

Posted by matlabbe on
URL: http://official-rtab-map-forum.206.s1.nabble.com/Small-number-of-ORB-features-between-similar-frames-tp8883p8885.html

Hi,

Depending how commons the same descriptors are seen again, only most descriminative ones will be matched in the vocabulary. However, rtabmap loop closure is done in two steps: 1) BoW using the vocabulary to find the most likely image, so here ~10 features will score, 2) we take the highest loop closure hypothesis and recompute the correspondences between the images (so only using descriptors form the 2 images to get more matches). If you open Constraints View with Reg/Strategy=2 or Reg/Strategy=0 (see Core Parameters panel), then click on Add Constraint, you will see the new correspondences in the images, they should be higher.

cheers,
Mathieu