A Robust Watermarking Algorithm Based on Image Normalization and DC Coefficients
Digital watermarking algorithms are prune to different attacks. Of these geometric attacks are recognized as one of the strongest attacks for digital watermarking technology. Normalization watermarking algorithm is resistant to geometrical distortions and DC coefficients are perceptually most significant and more robust to many unintentional attacks (signal processing) and intentional attacks (unauthorized removal). In this paper we propose a robust non-blind watermarking algorithm based on DC coefficients and normalization. By applying discrete wavelet transformation technique (DWT) followed by block based Discrete Cosine Transformation (DCT) technique, DC components are obtained. The cover image is normalized using normalization algorithm in different frequency bands using wavelet decomposition and then block based DCT is applied. In the DC coefficients of the sub-band of the image, watermark is embedded. The algorithm resistant to geometrical distortions (rotation, scaling) and different other attacks (histogram equalization, noise) on different contrast images. The quantitative measurements like SNR (Signal to Noise Ratio), MSE (Mean Squared Error), RMSE (Root Mean Squared Error) and PSNR (Peak Signal to Noise Ratio) are tabulated.
Keywords: Digital Watermarking, Normalization, Discrete Wavelet Transform (DWT), Discrete Cosine Transform (DCT).
Download Full-Text
ABOUT THE AUTHORS
Tumula Sridevi
T.Sridevi received B.E. from Osmania University and M.Tech.(CSE) degree from JNT University in 2002. She is pursuing her Ph.D. from Osmania University in Computer Science under the guidance of Dr V. Vijaya Kumar. She has 14 years of teaching/industry experience. She joined as Assistant Professor in Chaitanya Bharathi Institute of Technology, Hyderabad, India in 2002. Presently she is Associate Professor, CBIT, and Hyderabad. She has published 10 research publications in various international and national conferences and journals. Her research areas include Digital Water Marking, Image Processing and Soft Computing. She is a life member of IETE.
V. Vijaya Kumar
Vakulabharanam Vijaya Kumar received integrated M.S. Engg, degree from Tashkent Polytechnic Institute (USSR) in 1989. He received his Ph.D. degree in Computer Science from Jawaharlal Nehru Technological University (JNTU) in 1998.He has served the JNT University for 13 years as Assistant Professor and Associate Professor and taught courses for M.Tech students. He has been Dean for Dept of CSE and IT at Godavari Institute of Engineering and Technology since April, 2007.His research interests includes Image Processing, Pattern Recognition, Digital Water Marking and Image Retrieval Systems. He is a life member for CSI, ISTE, IE, IRS, ACS and CS. He has published more than 50 research publications in various National, Inter National conferences, proceedings and Journals.
Tumula Sridevi
T.Sridevi received B.E. from Osmania University and M.Tech.(CSE) degree from JNT University in 2002. She is pursuing her Ph.D. from Osmania University in Computer Science under the guidance of Dr V. Vijaya Kumar. She has 14 years of teaching/industry experience. She joined as Assistant Professor in Chaitanya Bharathi Institute of Technology, Hyderabad, India in 2002. Presently she is Associate Professor, CBIT, and Hyderabad. She has published 10 research publications in various international and national conferences and journals. Her research areas include Digital Water Marking, Image Processing and Soft Computing. She is a life member of IETE.
V. Vijaya Kumar
Vakulabharanam Vijaya Kumar received integrated M.S. Engg, degree from Tashkent Polytechnic Institute (USSR) in 1989. He received his Ph.D. degree in Computer Science from Jawaharlal Nehru Technological University (JNTU) in 1998.He has served the JNT University for 13 years as Assistant Professor and Associate Professor and taught courses for M.Tech students. He has been Dean for Dept of CSE and IT at Godavari Institute of Engineering and Technology since April, 2007.His research interests includes Image Processing, Pattern Recognition, Digital Water Marking and Image Retrieval Systems. He is a life member for CSI, ISTE, IE, IRS, ACS and CS. He has published more than 50 research publications in various National, Inter National conferences, proceedings and Journals.
