Here is a paper and demo describing creation of such codes: http://vecg.cs.ucl.ac.uk/Projects/SmartGeometry/halftone_QR/halftoneQR_sigga13.html http://vecg.cs.u

Here is a paper and demo describing creation of such codes: http://vecg.cs.ucl.ac.uk/Projects/SmartGeometry/halftone_QR/halftoneQR_sigga13.html http://vecg.cs.ucl.ac.uk/Projects/SmartGeometry/halftone_QR/... Sadly, original online demo doesn't work anymore, but by looking for "halftone qr code" you'll find plenty of alternative implementations like this: http://jsfiddle.net/lachlan/r8qWV/ http://jsfiddle.net/lachlan/r8qWV/