A Robust Medical Image Watermarking Based on DWT for Patient Identification

In this paper, we present a robust medical image watermarking based on discrete wavelet transform which embed a patient's name and ID number in a medical image with in an invisible manner. The watermark is available to the respective physician only on extraction with a secret key. Principally, the blue component of original host image is decomposed by the 2-D Discrete Wavelet Transform level-2 and the watermark image is decomposed by 2-D Discrete Wavelet Transform level-1. Then, the coefficients of watermark bits in LL subband-level-1 are embedded in the coefficients of the host image in HH sub-band-level-2. The experimental results showed the improvements in term of NC of the extracted watermark and the robustness of the embedded watermark, compared to the previous methods in [10] and [12].