Fractal tags detection


Does anybody knows if there is any chance to show Fractal markers implementation in OpenCV?

Like this one :

if you really wanted to draw those markers:

just add imshow / waitKey …

Thanks, but is there a way OpenCV decodes them?

currently, not so.

if you’ want to add those to opencv’s aruco module, you’d have to contact the author,
and ask for permission to re-license the resp. code as MIT/Apache2, since gpl’ed code is not acceptable here.

I asked him.
Do you know any other tags that should use the same concept (a tag inside another tag) and that should match OpenCV licence?

charuco boards, maybe ?

cool :wink:

1 Like

Have a look at AprilTag 3, and from the Wiki:

If you want to make a recursive tag use tagCustom48h12.

See the paper:


And it is BSD-2-Clause License


That sounds a good option…
I’ll have a look

Many thanks