A Robust Digital Image Watermark Algorithm Based on Fractal Theory
Jianli Hu · Computer Engineering and Applications Journal · 2006
In the paper,a new watermark algorithm that combines the wavelet zero-tree theory with fractal-based compression is presented.At first,the cover image is applied the wavelet transform,and is encoded on the basis of the mixed method that combines the zero-tree of wavelet domain with the fractal theory;Secondly,according to the characteristics of the Human Visual System(HVS),the positions of embedding the secret image are obtained,and in order to improving the level of information hidden,I apply chaotic sequence transform to the watermark sequence.The experiment proved that the algorithm can not only resist some kinds of transforms such as clipping,JPEG compression and so on,but also ensure the watermark image robustness.