Key-dependent pyramidal wavelet domains for secure watermark embedding

Wavelet filters can be parametrized to create an entire family of different wavelet filters. We discuss wavelet filter parametrization as a means to add security to wavelet based watermarking schemes. We analyze the influence of the number of filter parameters and use non-stationary multi-resolution decomposition where different wavelet filters are used at different levels of the decomposition. Using JPEG and JPEG2000 compression we assess the normalized correlation and Peak Signal to Noise Ratio (PSNR) behavior of the watermarks. The security against unauthorized detection is also investigated. We conclude that the proposed systems show good robustness against compression and depending on the resolution we choose for the parameters we get between 299 and 2185 possible keys.