Comparison of different wavelet transforms for fusion based watermarking applications

In this paper, we have investigated and assessed different wavelet transforms for use in fusion based watermarking applications. Scalar (discrete) wavelet, multiwavelet, complex wavelet and wavelet packet transforms have been studied to answer the following question: Which transform provides a better watermarking robustness given a certain imperceptibility factor? Fusion based watermarking has been chosen since it provides a visual authentication of the watermark. Perceptual embedding has been omitted to provide a fair comparison since different transforms have yielded different locations for the embedding process. It has been found that the CWT outperforms the other transforms while the WPT gives the worst results.