ORB Bug, compute removes all keypoints?

asked 2013-05-21 19:57:45 -0600

yes123
1412 ●12 ●28 ●52

I have a little image 50x50.

I do something like this (pseudocode):

 OrbFeatureDetector.detect(object,kp);
 //> kp.size() is about 50 keypoints

 OrbFeatureExtractor.compute(object,kp,kpDesc);
 //> Now kp.size() == 0

This mean that after I have called .compute the method has deleted all keypoints.

The Image I am using is this: image description

I believe this is some sort of bug. Someone can confirm? I am using OpenCV 2.4.5

edit retag flag offensive close merge delete

add a comment

1 answer

Sort by » oldest newest most voted

answered 2013-05-22 09:20:03 -0600

Guanta
6736 ●6 ●25 ●79

The reasons why you may not get any keypoints:

keypoints around the border will be removed
keypoints which don't have a strong response will be removed

So, I guess your iamge is too small and doesn't get good keypoints. Thus, other detector/descriptor combinations, e.g. using a dense grid in conjunction with SIFT. Alternatively upscale the image (maybe with a superresolution approach).

edit flag offensive delete link

Comments

I have solved by setting the right params to both objects: http://stackoverflow.com/questions/16688909/orb-compute-bug-it-removes-all-keypoints-with-a-small-image

yes123 ( 2013-05-22 12:25:48 -0600 )edit

Ah, so the problem was actually sth else - good to know!

Guanta ( 2013-05-22 12:38:27 -0600 )edit

add a comment

Links

Question Tools

Stats

Asked: 2013-05-21 19:57:45 -0600

Seen: 234 times

Last updated: May 22 '13

ORB Bug, compute removes all keypoints? edit