A robust image watermarking using DWT, SVD and Torus automorphism

Digital watermarking is a process to provide authenticity by hiding a data into an image or audio or document. Hiding of data in an image can be done in frequency domain. Since frequency domain based techniques are more robust against signal processing and geometric attacks than time domain techniques. One such frequency domain technique is developed based on combination of discrete wavelet transform, singular value decomposition and torus automorphism and is presented in this paper. This results prove that this method robust against different attacks and has good PSNR ratio.