Design of watermarking scheme in medical image authentication using DWT and SVD technique

Watermarking, which belong to the information hiding field, has seen an interesting research area recently. In this process digital watermarking widely recognized to be more prevalent to the problem of copyright protection of medical documents in networked environments. There are two important difficulties, that watermarking algorithms need to solve. First, watermarking schemes are required to provide trustworthy evidence for protecting rightful ownership. Second, good watermarking schemes should satisfy the requirement of robustness against various unintentional or malicious attacks. In this paper a watermarking scheme is developed for copyright protection of MRI i.e. medical images. A text image having patient details is embedded on the MRI images to generate an authenticated image which contains hidden patient data (not visible to naked eyes). Three methods are implemented for watermarking i.e. Discrete Wavelet Transform and Singular Value Decomposition. The PSNR (between original MRI image and generated secure image) and correlation (between patient text information and extracted watermark image) are calculated to check the robustness and capacity of the scheme. We have also developed code for different attacks with varying strengths to check the robustness of the watermarking algorithm.