DBow/FBow vocabularies in rtabmap

[akunin]

Hi,
have you considered using standard pre-trained vocabularies for BOW at least when using ORB features?
it might be more efficient..is there any work related to it?
thanks

[matlabbe]

Well, rtabmap BOW approach has been implemented (2009) before original DBOW was officially released. My research then moved in another direction. But yeah that could be very interesting to integrate one version of dbow to compare (maybe fbow as it seems to be the most recent). I see ORB_SLAM3 is still using DBoW2 though. Do you know if there is a paper or website comparing DBoW2, DBoW3 and FBoW?