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ORB Bug, compute removes all keypoints?

asked 2013-05-21 19:57:45 -0500

yes123 gravatar image

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

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answered 2013-05-22 09:20:03 -0500

Guanta gravatar image

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).

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yes123 gravatar imageyes123 ( 2013-05-22 12:25:48 -0500 )edit

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

Guanta gravatar imageGuanta ( 2013-05-22 12:38:27 -0500 )edit

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Asked: 2013-05-21 19:57:45 -0500

Seen: 134 times

Last updated: May 22 '13