Protecting Intellectual Rights: Digital Watermarking in the Wavelet Domain

The objective of the paper is to analyse the advantages and disadvantages of spatial, DFT, DCT and DWT domains and highlight the advantages offered by watermarking wavelet coefficients rather than the DCT or FFT coefficients. The reasons for the DWT advantage are analysed and the choice of a particular wavelet basis is explained. As an illustration of these advantages, the paper presents a high capacity blind video watermarking system, which embeds the data payload in the wavelet domain. In this paper the video sequence is regarded as a noisy communications channel, and the multi-bit watermark as the hidden message. In order to maximize the information capacity in the presence of attacks, the payload is embedded according to a HVS model, and is protected by state-of-the-art error correction (Turbo codes). It is shown that the DWT is significantly more robust to scaling and cropping, and gives a useful capacity improvement under a compression attack.