Block Based Video Watermarking Scheme Using Wavelet Transform and Principle Component Analysis Nisreen I. Yassin 1 , Nancy M. Salem 2 , and Mohamed I. El Adawy 3 1 National Research Centre, Cairo, Egypt. 2 Department of Biomedical Engineering, Faculty of Engineering, Helwan University, Egypt. 3 Department of Comm., Elect., and Computers, Faculty of Engineering, Helwan University, Egypt. Abstract In this paper, a comprehensive approach for digital video watermarking is introduced, where a binary watermark image is embedded into the video frames. Each video frame is decomposed into sub-images using 2 level discrete wavelet transform then the Principle Component Analysis (PCA) transformation is applied for each block in the two bands LL and HH. The watermark is embedded into the maximum coefficient of the PCA block of the two bands. The proposed scheme is tested using a number of video sequences. Experimental results show high imperceptibility where there is no noticeable difference between the watermarked video frames and the original frames. The computed PSNR achieves high score which is 44.097 db. The proposed scheme shows high robustness against several attacks such as JPEG coding, Gaussian noise addition, histogram equalization, gamma correction, and contrast adjustment. Keywords: Digital video watermarking, Principal Component Analysis, Discrete Wavelet Transform, Binary watermark. 1. Introduction Digital watermarking is a new technology used for copyright protection of digital media. Digital watermarking was introduced at the end of the 20 th century to provide means of enforcing copyright protection of digital data. Where, ownership information data called watermark is embedded into the digital media (image, audio, and video) without affecting its perceptual quality. In case of any dispute, the watermark data can be detected or extracted from the media and used as a proof of ownership. Imperceptibility and robustness against attacks are the fundamental issues in digital watermarking techniques [1-2]. Recently, digital video watermarking has emerged as a significant field of interest and a very active area of research [3]. Many digital watermarking schemes have been proposed for video. Most these schemes are based on the techniques of image watermarking, but video watermarking has some issues not present in image watermarking. This is because video sequences have some distinguish characteristics such as the temporal and inter-frame characteristics, which require specific approaches for video watermarking [4-7]. Video watermarking schemes can be classified into two main categories based on the domain which used for hiding the watermark bits in the host video. The first one is the spatial domain watermarking where embedding and detection of watermark is performed by directly manipulating the pixel intensity values of the video frame [8-9]. The second category is the transform domain techniques [10- 12] in which the watermark is embedded by changing the frequency components. The commonly used transform domain techniques are Discrete Fourier Transform (DFT), the Discrete Cosine Transform (DCT), the Discrete Wavelet Transform (DWT), and Principle Component Analysis transform. The frequency domain watermarking schemes are relatively more robust than the spatial domain watermarking schemes, particularly in lossy compression, noise addition, pixel removal, rescaling, rotation and cropping. Swanson [13] has proposed a scene-based video watermarking procedure in which the watermark is generated from a temporal wavelet transform of the video scenes. In Inoue [14] the watermark was embedded in the lowest frequency components of each frame in the uncoded video using a controlled quantization process. Chan et al. [15] propose a hybrid digital video watermarking scheme based on the scene change analysis and error correction code. He has used the Discrete Wavelet Transform by embedding in frequency coefficients of video frames. Hussein [16] embeds the watermark data to the HL and LH bands of the wavelet domain using motion estimation approach. The motion in these bands does not affect the quality of the frame. The PCA domain was first introduced to gray-scale image watermarking by Thai D. Hien et al. [17]. In [18] the PCA transform is used to embed the watermark in each RGB color channel of each frame of the video, where the same or multi-watermark can be embedded into the three color channels of the image in order to increase the robustness of the watermark. The main IJCSI International Journal of Computer Science Issues, Vol. 9, Issue 1, No 3, January 2012 ISSN (Online): 1694-0814 www.IJCSI.org 296 Copyright (c) 2012 International Journal of Computer Science Issues. All Rights Reserved.