Robust ROI Watermarking Scheme Based on Visual Cryptography: Application on Mammograms

Abstract

Abstract Inthis paper, a novel robust medical images watermarking scheme is proposed. In traditional methods, the added watermark may alter the host medical image in an irreversible manner and may mask subtle details. Consequently, we propose a method for medical image copyright protection that may remedy this problem by embedding the watermark without modifying the original host image. The proposed method is based on the visual cryptography concept and the dominant blocks of wavelet coefficients. The logic in using the blocks dominants map is that local features, such as contours or edges, are unique to each image. The experimental results show that the proposed method can withstand several image processing attacks such as cropping, filtering, compression, etc. Keywords Copyright Protection, Mammograms, Medical Image, Robust Watermarking, Visual Cryptography 1. Introduction The rapid advancement of the Internet and multimedia systems in these last years has led to the creation of many useful applications such as telemedicine, which requires exposing medical data over open networks. But, due to this development, digital media, such as images, video, audio, or text, can be easily distributed, duplicated, and modified. However, in a number of medical applications, special safety and confidentiality is required for medical images, because critical assessments are made based on those images. Therefore, there is a need to provide strict security to ensure only the occurrence of legitimate changes [1]. Digital image watermarking techniques have been developed to protect the intellectual property of a digital image. This is achieved by embedding the copyright information, which is also called “the watermark pattern,” into the original image. Copyright protection is achieved by robust watermarking while image authentication is usually achieved by fragile schemes. A fragile watermarking scheme detects any manipulation made to a digital image to guarantee the content integrity while a robust scheme prevents the watermark from being removed unless the quality of the image is greatly reduced.