Blind DT-CWT Domain Additive Spread-Spectrum Watermark Detection
Roland Kwitt, Peter Meerwald and Andreas Uhl
16th International Conference on Digital Signal Processing, DSP '09
Santorini, Greece; July 5 - 7, 2009
as BibTeX-file
conference program
Abstract
In this paper, we adapt two blind detector structures for additive spread-spectrum image watermarking to the host signal characteristics of
the Dual-Tree Complex Wavelet Transform (DT-CWT) domain coefficients. The research is motivated by the superior perceptual characteristics
of the DT-CWT and its active use in watermarking. To improve the numerous existing watermarking schemes in which the host
signal is modeled by a Gaussian distribution, we show that the Generalized Gaussian nature of Dual-Tree detail
subband statistics can be exploited for better detector performance. We found that the Rao detector is more practical than the
likelihood-ratio test for our detection problem. We experimentally investigate the robustness of the proposed detectors under JPEG and
JPEG2000 attacks and assess the perceptual quality of the watermarked images. The results demonstrate that our alterations allow
significantly better blind watermark detection performance in the DT-CWT domain than the widely used linear-correlation detector.
Links
Peter Meerwald, pmeerw@cosy.sbg.ac.at