An interpolation-based watermarking scheme

Interpolation techniques are often designed to provide a good perceptual quality from known sample values. However, interpolation is essentially considered as a source of decoding errors for watermarking schemes. Conversely, this paper proposes an informed watermarking scheme based on interpolation. This scheme takes advantage of interpolation to generate imperceptible marks in the spatial domain. It can be related to random binning schemes with particular codebook and decoding rule. Theoretical performances are derived and informed embedding strategies are proposed. Two particular implementations based on bilinear and spline interpolation are then applied to image watermarking. The good robustness of these schemes to noise and valumetric attacks is confirmed by simulations. Finally, an attack is specifically designed to check the algorithm security.