Prediction based reversible watermarking with contrast modification

Reversible watermarking (RW) is used to embed some useful information into digital content in a reversible manner, where the reconstruction of the original image is highly desirable. This reversibility is important for almost all sensitive image application domains such as medical and military fields. To this aim here we have proposed a hybrid algorithm that offers higher embedding bit rate with a considerable low visual distortion. The proposed algorithm is a hybrid model of modified reversible contrast mapping (RCM) and prediction error expansion (PEE) used in RW. The benefits of RCM that provides higher embedding space and PEE algorithm that allows higher embedding bit rate are used combinedly. Both the attributes are used here in one integrated form that allows high data embedding rate with low embedding distortion. In a single pass embedding, the proposed algorithm provides 1.33 bpp, 1.15 bpp, 1.024 bpp and 1.085 bpp for Lena, Boat, Baboon and Elaine images, respectively.