Digital watermarking of spectral images with three-dimensional wavelet transform

We propose a watermarking method for spectral images. The watermark is embedded in the three-dimensional wavelet domain of the image. Before embedding, the gray-scale watermark is transformed with the two-dimensional wavelet transform. After embedding the inverse three-dimensional wavelet transform reconstructs the image now containing the watermark. The strength of embedding is controlled by perceptual constraints and reconstruction quality. The experiments indicate, that the robustness against attacks like PCA/wavelet compression is good.