MATCHES = VL_UBCMATCH(DESCR1, DESCR2) matches the two sets of SIFT descriptors DESCR1 and DESCR2.
[MATCHES,SCORES] = VL_UBCMATCH(DESCR1, DESCR2) retuns the matches and also the squared Euclidean distance between the matches.
The function uses the algorithm suggested by D. Lowe [1] to reject matches that are too ambiguous.
VL_UBCMATCH(DESCR1, DESCR2, THRESH) uses the specified threshold THRESH. A descriptor D1 is matched to a descriptor D2 only if the distance d(D1,D2) multiplied by THRESH is not greater than the distance of D1 to all other descriptors. The default value of THRESH is 1.5.
The storage class of the descriptors can be either DOUBLE, FLOAT, INT8 or UINT8. Usually integer classes are faster.
- REFERENCES
[1] D. G. Lowe, Distinctive image features from scale-invariant keypoints. IJCV, vol. 2, no. 60, pp. 91-110, 2004.