A Hybrid Scheme for Robust Color Image Watermarking Using DSWT in DCT Domain Khalid A. Al-Afandy Department of Computer Science & Engineering Faculty of Electronic Engineering, Menoufia University Menouf, Egypt Khalid_yuosif@yahoo.com Osama S. Faragallah Department of Computer Science & Engineering Faculty of Electronic Engineering, Menoufia University Menouf, Egypt osam_sal@yahoo.com, o.salah@tu.edu.sa El-Sayed M. EL-Rabaie, Fathi E. Abd El-Samie Department of Electronic and Communication Engineering Faculty of Electronic Engineering, Menoufia University Menouf, Egypt Srabie1@yahoo.com, fathi_sayed@yahoo.com Ahmed ELmhalawy Department of Computer Science & Engineering Faculty of Electronic Engineering, Menoufia University Menouf, Egypt Ahmed.elmahalawy@el-eng.menofia.edu.eg Abstract—This paper proposes a hybrid robust image watermarking scheme based on three levels of Discrete Stationary Wavelet Transform (DSWT) in the Discrete Cosine Transform (DCT) domain. The host image colors (red, green and blue) are separated, and then the DCT is applied on each color after separation. The DSWT is utilized to divide the DCT output into four sub-bands (3 levels). These sub-bands are (A, H, V, D) matrices with the same image size. The watermark is embedded on matrix A. The results of the proposed watermarking scheme are compared with other state-of-the-art schemes. The comparison is based on visualization to detect any degradation of the watermarked image, Peak Signal-to-Noise Ratio (PSNR) of the watermarked image, Normal Correlation (NC) of the extracted watermark after detection, applying attacks, and then calculating the PSNR and NC. Keywords— Watermarking; Discrete Stationary Wavelet Transform (DSWT); Discrete Cosine Transform (DCT). I. INTRODUCTION Information such as digital data and multimedia can be easily duplicated, manipulated, and redistributed. |So, it is very important to have copyright protection to save owners copyrights. There are many protection techniques, one of them is watermarking. Watermarking technology is the process of hiding an image called watermark or label into original digital data (image, video, or audio) [2,3]. Watermarked image must be robust enough to survive attacks [4]. Watermarking schemes can be classified into two categories; spatial domain and transform domain [5]. There are several schemes of transform domain watermarking technology. One of these schemes of transform domain is Discrete Cosine Transform (DCT) [9]. This transform is used to convert spatial domain image into discrete transform domain [12]. The watermarking scheme is based on transforming the RGB color image to 2D DCT for each color, embedding the watermark into the DCT, and then inverting the DCT to get the watermarked image [9-14]. Another used scheme is the Discrete Stationary Wavelet Transform (DSWT) [1]. It is similar to the DWT except that the signal is not sub-sampled, but instead, the filters are up-sampled at each level of decomposition [8]. It gives a better approximation than DWT because of its linearity and redundancy [7]. The DSWT divides an image into four sub-bands; approximation sub-band (A), horizontal sub-band (H), vertical sub-band (V), and diagonal sub-band (D) [1,7,8]. The main aim of this paper is to propose a hybrid scheme to achieve robust watermarking. The proposed scheme in this paper is the discrete stationary wavelet transform in the discrete cosine transform domain. The DCT DCT is applied on each color after separating host image colors (red, green and blue). The DSWT is utilized to divide DCT domain into four sub-bands (3 levels). These sub-bands are (A, H, V, D) matrices with the same image size. The watermark embedding is performed on matrix A. The rest of this paper is organized as follows. Section II gives a literature review. The proposed scheme is discussed in section III. Section IV shows the simulation results. Section V presents the conclusions followed by the more relevant references. II. LITERATURE REVIEW A. Discrete Cosine Transform (DCT) Discrete Cosine Transform (DCT) is a stand-out amongst the most well-known orthogonal change strategies utilized as part of picture preparation. High vitality compaction property of DCT is the reason. In watermarking, this property helps in choosing the area in the picture to insert the watermark with the highest degree of robustness [3]. The DCT divides the image into three frequency bands, namely low, middle, and 978-1-5090-0751-6/16/$31.00 ©2016 IEEE 444