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].