A RST-invariant Robust DWT-HMM Watermarking AlgorithmIncorporating Zernike Moment and Template[J]. Journal of Image and Graphics, 2008, 13(7): 1250-1257. DOI: 10.11834/jig.20080705.
A RST-invariant Robust DWT-HMM Watermarking AlgorithmIncorporating Zernike Moment and Template
One of the key issues for robust watermarking is to resist geometrical attacks. A matching strategy from coarse to fine scale to achieve the geometrical synchronization incorporating Zernike moments and the template in wavelet domain is proposed. At the coarse stage
the rotation and scaling parameters are estimated with the Zernike moments of the translation normalized image
while the translation parameters are estimated with the centroid’s increments between the original image and the image that are corrected for rotation and scaling. At the fine stage
the accurate values of rotation
scaling
and translation (RST) are obtained by matching the template around the roughly estimated RST values
which hence reduces the searching spaces to some extent. Finally
the attacked image is corrected with the accurate RST values. A watermarking scheme based on the vector Hidden Markov Model in wavelet domain (DWT HMM) is also adopted. Good robustness is observed against StirMark attacks and their joint attacks.