Abstract
This paper proposes a watermark, W, a set of independent and identically distributed Gaussian pseudo random signals, which is embedded into the coeÆcients 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 veri cation 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.