Moment based multibit digital image watermarking resisting to RST attacks

At present, most image watermarking schemes can not effectively resist geometrical attacks, which restricts the applications of digital watermarking techniques. RST (Rotation, Scaling, Translation) are frequently used geometrical attacks. In this paper a general multi-bit watermarking scheme for digital image that can resist to RST attacks is proposed. The measures taken in the scheme include: (1) a moment-based image normalization method is proposed to resist RST; (2) The multi-bit message is hidden in a 2D CDMA watermark using spread spectrum technique; (3) The watermark is embedded into cover image exploiting the properties of HVS to obtain the compromise between watermark robustness and invisibility. (4) The watermark is estimated according to MAP and detected by means of correlation-detection. Experimental results show the scheme is robust to compression, filtering as well as RST attacks.