The widespread use of QR codes motivates a vast creation of eyecatching visual QR codes. Most of the visual QR codes are creative artworks made by skilled artists or design experts. There is a website, QR code R Artist [D’Haem 2010],
that keeps track of news and related resources about creative QR code artworks, and a plentiful art gallery could be found in a flickr QR code art group [flickr 2009].
Owing to the commercial value behind such visually appealing QR codes, most resources for creating artistic QR codes are proprietary and only a few online tutorials [Chan 2011; Scheib
2010] are available.
Commonly used strategies by artists to customize a QR code include adding colors to modules, rounding the hard edges, and embedding a small image in a QR code that relies on inbuilt error correction capacity of QR code to restore from missing modules (see Figure 2(a)).
These attempts generally require a trial-and-error style process to manually refine their works followed by a readability verification process as evidenced in online custom QR code design tools [Laporte 2012].