Zero - Watermarking scheme for unique patient identification tags in fundus images for tele-ophthalmologic applications

Abstract

This paper proposes a method of zero-watermarking scheme to generate a unique digital identification tag having patient’s identity without tampering the details of the medical information present in the image. Using the features of the original medical image, the digital identification tag is encrypted and a unique master key is created which can be decrypted by using the original medical image at the receiver’s end. This is performed by using strategic decomposition of digital wavelet transform along with singular value decomposition to obtain a unique identity vector which is used in a function along with the image’s watermark to create the master share for that image. Images of the fundus comprise of very fine features like macula, optic disks and blood vessels. Traditional watermarking techniques might tamper with the crucial information stored in the medical image. Even the smallest of changes can result in noise and distortion of the fine features of the medical image and can affect the final decision which would be made by the doctor. The method proposed in this paper does not tamper with any details of the image in order of watermarking the digital identification tags onto the image.