ALTERNATE MULTIBIT EMBEDDING METHOD FOR REVERSIBLE WATERMARKING

This paper proposes a new embedding scheme for multibit difference expansion reversible watermarking. The prediction error expansion (PEE) schemes expand n times the difference in order to embed up to log(2) n, bpp. For natural images, this capacity cannot be achieved because overflow or underflow is generated by the embedding process. The proposed method aims to increase the capacity of the embedded information by using a different embedding procedure when the classical one fail. Although the proposed embedding method introduces larger distortion than classical procedure, the experimental results show that the proposed scheme provide an increase of the embedding capacity and outperforms the classical method regarding the image quality with respect to capacity. Experimental results using the classical and proposed multibit difference expansion based on the MED predictor are provided.