Some markers are ignored while others are read

A few things come to mind, but I’m just making guesses.

  1. Some of the markers “covered with adhesive tape” have some visible lines / streaks on them, presumably from where the tape wasn’t adhered well. Aruco detection is pretty robust, but it’s possible this is throwing it off.
  2. The ones not being detected seem larger in the image - maybe your detector parameters (maxMarkerPerimeterRate?) aren’t right for the larger markers.
  3. Make sure you have enough white boundary around the marker - it looks like you do, but it’s something to be aware of.
  4. I know you said they are from the same dictionary, but it might be helpful to have identical markers to test with - one with the tape, the other without. In my experience some markers are easier / more reliably detected.

I think there is a way to get debug / intermediate processing results out of the Aruco detection. I’ve done something with that, but maybe I was building from source / editing the code. In any case, it could be helpful to see where/why it is failing.

Frankly I would expect it to work on your images, so I’m leaning toward detector parameters (or invalid marker).

Good luck.