Digital Watermarking for Image AuthenticationBased on Combined DCT, DWT and SVD Transformation

Digital content can frequently copied by unauthorized person and claim to his ownership. But we don’t know who the actual owner of that content is. Digital Watermarking is an important issue to solve this kind of problem. This paper presents a hybrid digital image watermarking based on Discrete Wavelet Transform (DWT), Discrete Cosine Transform (DCT) and Singular Value Decomposition (SVD) in a zigzag order. From DWT we choose the high band to embed the watermark that facilities to add more information, gives more invisibility and robustness against some attacks. Such as geometric attack. Zigzag method is applied to map DCT coefficients into four quadrants that represent low, mid and high bands. Finally, SVD is applied to each quadrant.