Monochrome: using shapes/patterns instead of colors?

[HenrikBengtsson]

Instead of color coding programs, do you think it would be possible to encode them by using different orthogonal, distinct shapes and fill patterns as an alternative, e.g. solid squares, empty square, triangles, upside-down triangles, plus symbol, and so on?

That would lower the entrance barrier to those who only got a monochrome printer at home.

PS. Thanks for sharing this and making it open source. I've stumbled upon the Dynamicland website and Twitter feed, but failed to get ahold of DIY info or source code, so I was happy to see yours.

[forresto]

https://archive.artoolkit.org/documentation/doku.php?id=3_Marker_Training:marker_barcode has info on "2d barcode" monochrome trackers for AR. The dots are better-suited for framing a page though.

[blakebjorn]

Using black circles and filling in a percentage of the interior would probably work fine.

If each circle had 6 'pie pieces' which could be either empty, or black, you could use otsu's binarization to classify each piece as 0, 0.17, 0.33, 0.5, 0.66, 0.83, 1.0 after running what i assume is hough circles to isolate the markers.

This means with 4 circles, one in each corner, there would be a fairly substantial number of combinations if you take clockwise order into account.

[forresto]

One issue that I noticed at DL is that some projected graphics can obscure tracking, especially as the sun sets, making the projections brighter relative to the room. Do you have any idea if monochrome tracking dots would be more or less susceptible to this?

[janpaul123]

Yeah, I originally experimented with QR codes but the resolution was not high enough. There're some good ideas here though!