[rgnpbvzr] Information in dot arrangement

Devise a method to robustly encode information in a pattern of dots.  Inspiration is steganography.  A zen garden with stones.

Let the method be robust against transformation and deformation.  This allows the dots to be hand-drawn.  One possible encoding is in the geometric arrangement: what dots are inside what triangles, etc.  Probably want error-correcting codes.  Computer vision machine decoding.

Lay out a triangular lattice of dots.  Encode 1 bit by possibly placing a dot within a triangle.  Though this is probably too obvious for steganography. (I think square doesn't work because of ambiguity of all bits set. Nor hexagon.)