| Digital watermarking is a relatively overhead free solution to the problem of copyright infringement. In this thesis we investigate the choice of transform domain for embedding blind and non-blind watermarks in the face of eight different attacks. The chosen attacks are commonly used in watermark benchmarking programs. After extensive simulations involving seventeen different transforms, we find that our findings corroborate the results obtained by Ramkumar et al. [1] for compression attacks.; In addition, we analyse the Voloshynovskiy scheme for its probability of false alarm in a novel way. We then use the transform domain chosen from above and introduce the use of the SAGE algorithm as a parameter estimator. This algorithm is used to lower the probability of false alarm for the Voloshynovskiy scheme by improving the accuracy of parameter estimation and therefore lowering the variance of the detector output. |
