Robust digital image watermarking using DWT+SVD approach

Due to advanced tools available in computer technology, it is possible for unknown users to access the digital multimedia data. In order to protect important data from unauthorized people, this paper proposed a novel watermarking technique for color images. The proposed technique uses a unique combination of HL sub-band of Discrete Wavelet Transform (DWT) and Singular Value Decomposition (SVD). The singular matrices obtained by applying SVD to the DWT applied watermark image, are added to the singular matrices obtained by applying SVD to the DWT applied host image, in proper proportion. The quality of the watermarked image is estimated in terms of the Peak Signal to Noise Ratio (PSNR) and correlation coefficients. Experimental results applied on benchmark test images show promising performances for the algorithm proposed.