Résumé:
Dual-Tree Complex Wavelet Transform (DTCWT) is relatively a recent improvement of
the Discrete Wavelet Transform (DWT) with important additional properties like shift
invariant and directionality.
In this thesis, we propose a blind watermarking scheme based on Dual Tree Complex
Wavelet Transform (DTCWT). Single level DTCWT is applied on host image, it decompose
the original image into dual nine subbands. by modification on singular value
decomposition (SVD), Eigen values of the selected subband are replaced by the Eigen
values of the selected subband of the watermark which is multiplied by an appropriate
strength factor.
DTCWT provides higher capacity than the real wavelet domain. Modification of the appropriate
sub-bands leads to a watermarking scheme which favorably preserves the quality.
The additional advantage of the proposed technique is its robustness against the most of
common attacks. Analysis and experimental results show much improved performance of
the proposed method in comparison with the Hybred method SVD-DWT.
