Ask Your Question

Comparing patterns on coins.

asked 2016-03-04 13:57:29 -0500

Hello. I'm having a trouble comparing patterns on coins. I have fully working comparison of diameters, but some coins sadly have the same diameter. How can I accurately compare these patterns. I'd like it to be rotation invariant. It doesn't have to be scale invariant, because camera is always on the same height. I tried many things. I tried feature detectors like SIFT, SURF, FREAK, but i couldn't get anything to work properly. I don't want to use learning machine.

What would be the best method to use in comparing images like these? All help appreciated.

image description image description image description image description

edit retag flag offensive close merge delete

1 answer

Sort by ยป oldest newest most voted

answered 2016-03-04 19:18:46 -0500

Tetragramm gravatar image

There is a function that should do exactly what you need, and it works with the images you have provided here. The huMoments are invariant to scale, rotation, and reflection.

Just take your binary images and run them through cv::moments, cv::huMoments and compare the results (You can see the L1, L2 and L3 comparisons HERE).

edit flag offensive delete link more

Question Tools

1 follower


Asked: 2016-03-04 13:57:29 -0500

Seen: 224 times

Last updated: Mar 04 '16