On the realization of robust watermarking system for medical images

A medical image watermarking system based on Discrete Wavelet Transform (DWT) has been presented in this paper. Before watermark embedding, a medical image is subjected to global DWT. Haar wavelet has been used for this purpose. The LH sub band has been divided into 8×8 blocks. The coefficients of each 8×8 (LH) block are compared and if necessary swapped to embed either binary digit `1' or `0'. The scheme has been evaluated using various image quality matrices like Peak Signal to Noise Ratio (PSNR), Structural Similarity Index (SSIM) Bit Error Rate (BER) and Normalized Cross Co-relation (NCC). It has been observed that the proposed technique is capable of producing high quality watermarked images, besides being more robust as indicated by comparison results.