I've read news about FREAK in OpenCV 2.4.2. Is FREAK scale and rotation invariant, like SURF? Is it as good as SURF?
SURF is a detector like FAST. FREAK is a descriptor extractor. It has more sense to compare it with SIFT.
Actually, in the paper they say they use FREAK descriptors together with a pyramidal FAST detector that is called AGAST.
So answering your question:
It is rotation and scale invariant.
It is supposed to be a more robust descriptor than SIFT. I am going to test it but still don't have results.
Hi!
I recommend you to read the paper FREAK: Fast Retina Keypoint. Alahi et al. CVPR2012.
The authors claim that FREAK is scale and rotation invariant and even more robust than SURF.
I hope this helps.
It's actually a little bit more subtle: the pairs used by FREAK were chosen for their matching performance after a scale-sensitive detection of keypoints (the KP detector used is the same as BRISK, i.e. a multi-scale FAST + orientation detection). Hence, FREAK is rotation and scale invariant only up to the sensitivity of this detector and is not per se invariant.
Asked: Aug 4 '12
Seen: 2,773 times
Last updated: Nov 05 '12
Goodness is a relative measure - you should try both of them for your specific situation, and choose the best trade-off between quality, speed, and probably other factors.