Monocular orbslam 2 - Video segment problems

[mcsoares1992]

Hi, first of all thank you guys for making available this excellent tool.

I'm a Electrical and Computer Engineering student and i would like to apply monocular orb slam to a video segment of medical context (endoscopy) , like the one in this link https://drive.google.com/open?id=1lYwWfD1sKYv7YJ9YYQrGpEMviHh6c7iH . Using kitti example i have successfully loaded the video into orbslam, however i can't obtain any point cloud or map or keyframes. In this regard i have 3 questions:

• since i have the camera calibration parameters, i have to feed the orbslam an undistorted version of the video segment or orbslam handle it? ( i updated the YAML file and put the camera parameters there)
• Do you think that i need to generate another orb vocabulary or is supposed to use the one given in the vocabulary forder?
• Do the fisheye video insert any problem to orbslam?

If someone could help, i will be deeply thankful. with the best regards

[AlejandroSilvestri]

@mcsoares1992

• ORB-SLAM2 handle distorted video, you don't need to undistort it.
• The vocabulary provided with ORB-SLAM2 is widely applicable, you don't need a specialized vocabulary.
• Fisheye is a problem

ORB-SLAM2 uses the usual undistortion parameters, I personally couldn't successfully undistort fisheye video with them. I modified orb-slam2 code to use fisheye undistortion, and it works well.

Keep in mind: ORB-SLAM2 is hard to initialize. You must find a zone in your video where ORB-SLAM2 can initialize. Only after that SLAM starts working and the production of mappoints and keyframes begins.

Another note: ORB-SLAM2 works on static scenes. If your scene is elastic, its map will be ill formed.