An Improved Scheme for Watermarking QR-code Based on SVD in NSCT-CT
Miaohe Dai, Yong Zhao, Yule Yuan, Jingjing Li · 2013
In this paper, a novel scheme for watermarking QR-code is proposed based on Singular Value Decomposition (SVD) in nonsubsampled contourlet transform (NSCT) and contourlet transform (CT). For extraction actuality and detection accuracy, CT is performed before decomposing each block segmented from the chosen sub-band for singular values. Unlike the published work in this area, which quantizes certain amounts of singular values with fixed step, we obtain watermarked image by setting particular coefficient for the blind fusion of the selected significant singular values with watermark values. Different from previous schemes, our scheme is designed for QR code and its intelligent self-rectified approach is also indicated. Experimental results demonstrate that the proposed scheme enormously outperforms previous schemes.