A blind & fragile watermarking scheme for tamper detection of medical images preserving ROI

This paper proposes a blind and fragile medical image watermarking technique which embeds data in Region of Non Interest (RONI) while avoiding the region of interest (ROI) to get distorted. Watermarking is done in spatial domain and made fragile so that the watermark immediately gets disturbed as soon as host image gets attacked or manipulated. Watermark consists of patient information and the mean intensity value of ROI so that the ROI cannot be replaced by an intentional attack. Isolation of ROI and RONI from image is done automatically. The proposed scheme has been tested for lungs CT scan images and has provided encouraging results. The watermark immediately gets disrupted as soon as watermarked image is attacked or modified, leading the medical practitioner know that image has been tampered. High PSNR values imply that perceptual properties of the images are well maintained even after data embedding.