Pictorial vs 2D Barcode markers for better recognition

[ryatkins]

We have a multi-marker setup and looking for better marker recognition in our application. Right now we are using (9) 3x3 2D barcode markers with parity and I'm wondering if that is the best for our setup. Only two markers are shown at a time to the camera.

Would we see an advantage by going from 3x3 (w/ parity) to 4x4 with error checking?

Would we see any advantage with going to pictorial markers vs barcode markers?

Is there a desired width percentage for the outside contrasting border when compared to the marker size? (I'm aware that the inner border defaults to 25%)

Thanks,
Ryan

[ryatkins]

I found that the 4x4 barcode markers were worse than the 3x3. Can anyone back that up?

[philip_lamb]

In theory the 4x4 markers with error correction should produce fewer false positive recognition events than 3x3, because the error-correction is stronger, however if the markers are very small, you might run up against the smaller pixel area reducing the number of correct positive recognitions.

In any case, it's advisable to have a clear area of background around the marker of the same width as the marker border, but this isn't fixed.