Reversible watermarking in medical images using Histogram shifting method with improved security and embedding capacity

The major requirement for medical image watermarking is the reversibility of the medical image after extracting watermark. In this paper, we propose a secured reversible watermarking technique for medical images using Histogram shifting method. We provide extra security to the given watermark with chaos encryption. The given watermark is encrypted with chaos sequence prior to embedding in the given medical image. Also the block based technique is evaluated for increased watermarking capacity. The results of technique are compared on the basis on MSE and PSNR.