Blind Medical Image Watermarking with LWT – SVD for Telemedicine Applications

This paper highlights the extension of dwt-svd based image watermarking to medical images. In recent times internet has become a primary source of communication between the diagnostics center and the remote doctor located at some hospital. With the use of internet come the problem of data authenticity and the responsibility of the medical practitioner to preserve sensitive information of patients contained in the medical images related to that particular patient. Hence we have made an attempt to solve this problem by using dwtsvd based watermarking technique used for normal images. For medical images quality preservation is obligatory we have used 2D lifting wavelet transform (LWT) instead of dyadic 2D discrete wavelet transform. To test our algorithm we used computer tomography (CT) images as the original images. The watermark is chosen as patient picture which is hidden in a CT medical image while transmitting through internet. The results show that after attacks lwt-svd method gives satisfactory quality both visually and mathematically. Key-Words: Medical Image watermarking, Lifting Wavelet Transform, Singular Value Decomposition, Computer Tomography, lwt-svd watermarking.