Hash and Prediction-Error-Based Reversible Watermarking for Medical Images

In reversible watermarking (RW), the original cover image and the watermarked information are restored without any distortion. A secure RW technique using hybrid prediction and difference pair mapping along with the hashing algorithm is proposed in this paper. The four-stage imperceptible watermarking employed in this technique enlarges the payload capacity with low distortion in stego-image. The data authentication is used for protection of message integrity and validation of originator identification. Mean square error and peak signal-to-noise ratio are used for analyzing the robustness of the watermarked image. The simulation result shows that this method performs better than the other existing state-of-the-art methods.