Zero-watermarking for copyright protection of remote sensing image

Watermarking technique is the main method for copyright protection. But this technique does not suit remote sensing image because the embedded watermark heavily affects the results of its applicative tasks. In order to protect remote sensing image, this paper proposes a robust zero-watermarking method that constructs watermarks from the host data instead of embedding watermark into that data. The proposed method constructs two watermarks from host image. One is constructed from low-frequency coefficients in discrete wavelet transform domain of the host image, and the other is constructed from that of the log-polar mapping image of the host image. Experiments show that this method is robust to both signal processes and geometrical distortions.