Abstrakt

MULTILAYER SECURITY BASED ROBUST WATERMARKING TECHNIQUE FOR MEDICAL IMAGES IN DWT-DCT DOMAIN

Baisa L. Gunjal, Suresh N. Mali

This paper provides strongly robust digital image watermarking scheme for medical images using DWT-DCT domains. Security levels are increased by using different pn sequences, threshold values, summation of pn sequences, Arnold periodicity, Arnold scrambling, DWT and DCT domains. The medical images of 512x512 size used as cover images and grey scale hospital logo of 64x64 size is used as watermark and results are tested for 11 different values of flexing factor with middle and high frequencies then analysed and compared. The scheme gives PSNR up to 42.8846 and NC 0.9451 for high frequency sub band. The robustness with different noise and filtering attacks are tested and presented. Simple, symmetric, orthogonal ‘Haar’ wavelet is used for decomposition and direct flexing factor is used.