Wrong Hamming norm value between two ORB descriptors

asked 2016-01-27 06:27:09 -0600

ale_Xompi gravatar image

I'm currently working on feature point tracking and I want to compare the ORB descriptor of the current point with the previous one. I want to discard that point if the hamming distance between the two descriptors is higher than a specific threshold.

When I'm running hamm_dist = norm(pointDescr1, pointDescr2, NORM_HAMMING), the returned value sometimes is greater than 32 and I can't understand why. I was thinking it should be between 0 and 32.

Please let me know if you have an explanation. Thank you in advance.

edit retag flag offensive close merge delete

Comments

Hamming distance is bits that differ. You may be mistaking 32 bytes for 32 bits.

Der Luftmensch gravatar imageDer Luftmensch ( 2016-01-27 08:12:26 -0600 )edit

Thank you for your answer. Yes, you're right. That means the range of the Hamming distance between two ORB descriptors is [0,256], right?

ale_Xompi gravatar imageale_Xompi ( 2016-01-27 10:27:41 -0600 )edit
add a comment