May 2020
tl;dr: A summary of classical keypoints and descriptors.
- BRIEF: Binary Robust Independent Elementary Features ECCV 2010
- The sampling pattern is randomly generated but the same for all image patches. In openCV, the sampling sequence is pre-fixed.
- patch window is 31 x 31.
- blog review on BRIEF descriptor
- ORB: an efficient alternative to SIFT or SURF ICCV 2011
- Sampling pairs should have uncorrelation and high variance to ensure the fixed length would encode maximum discriminative information.
- ORB is improved BRIEF:
- ORB uses an orientation compensation mechanism, making it rotation invariant.
- ORB learns the optimal sampling pairs, whereas BRIEF uses randomly chosen sampling pairs.
- blog review on ORB
- Summaries of the key ideas