To compare the performance
of halftone QR code with original QR code, we randomly
selected 5 out of 91% successful results and corresponding original
QR codes, then separately applied to images Gaussian noise with
various amounts from 10% to 100%, Gaussian blur with kernel radius
from 0.5 to 6 pixels, and scanned the code at tilted angle from
10 to 75 degrees. Each QR code was scanned by three users using
four barcode readers. As shown in Figure 7((c)-(e)), the halftone
QR codes stop being functional under excessive setting of Gaussian
noise (40%), Gaussian blur (2 pixels) and viewing angle (40 degrees),
while the original QR codes crash at Gaussian noise (80%),
Gaussian blur (6 pixels) and viewing angle (60 degrees). In fact,
this tradeoff allows our algorithm to create visual QR codes.