B. Comparison of Time Complexity and Visual Quality
Fig. 9 demonstrates the comparison results of time complexity
and that of visual quality between the proposed method
and the research work [8]. Fig. 9(a) shows that the visual
quality of the proposed method for the whole QR code is
slightly lower than that of the study [8]. However, Fig. 9(b)
demonstrates the visual quality of our method for the salient
regions is almost 10 times better than that of [8]. Notice that,
in these comparisons, the visual quality is measured by the
Hamming distance between the original image
and the designed QR code . Fig. 10 illustrates the visual
differences of the beautified QR codes and the corresponding
noise distributions between our method and the research work
[8]. As pre-described, the visual difference is evaluated based
on the whole image and the salient regions, respectively.