Watermarking experiments based on wavelet transforms

This paper proposes a watermark, W, a set of independent and identically distributed Gaussian pseudo random signals, which is embedded into the coefficients of the high-low band and -W is embedded into those of the low-high band at level 3 in a 3-scale wavelet transform. A watermark generation, insertion, extraction, and verification after a variety of attacks via image operations such as scaling, smoothing, cropping, noise adding, JPEG, SPIHT, and fractal compression, are demonstrated by using Haar and Daubechies' four wavelet transforms on the image Lenna. Experiments reporting the PSNR value of each attacked image with its corresponding detected level show that the proposed watermarking strategy is promising.