Robust digital watermarking based on local invariant radial harmonic fourier moments

Abstract

It is a challenging work to design a robust image watermarking scheme against local geometric distortions. Radial harmonic Fourier moments (RHFMs) is a powerful tool in image processing owing to its better image description capability, lower noise sensitivity, and geometric invariance property. Based on SURF (Speeded-up robust features) detector and invariant RHFMs, we proposed a robust image watermarking scheme against local geometric distortions in this paper. Firstly, the SURF detector, which is a fast and highly performant multiscale feature detector, is used to extract image feature points in original image. Secondly, the stable and non-overlapped local circular regions centered at feature points are thereafter constructed and selected by combining characteristic scales and feature points refinement. And finally, the digital watermark is embedded in the invariant RHFMs of the local circular regions. Similarly to watermark insertion, the digital watermark can be blindly detected from the local circular regions. Experimental results confirm the validity of our approach and its higher robustness against various attacks (especially local geometric distortions) compared to alternative watermarking methods in the literature.