الفهرس 
Chapter1 IntroductionOnly 14 pages are availabe for public view
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Abstract
Advanced Video Coding (H.264/AVC) is one of the most important video coding standards which was developed by the ITU-T Video Coding Experts group (VCEG) together with the ISO/IEC Moving Picture Experts group (MPEG). Due to the complex procedures needed to find the optimal mode in intra prediction mode stage of H.264/AVC, an efficient mode decision is suggested. Saving compressed videos streaming from the unlawful users became an urgent claim. Cryptography and Steganography are the most important and indispensable processes to protect and embed the multimedia data during the transfer or storage process. Chaotic-based cryptography has been proposed to be an efficient encryption technique for multimedia applications and has played a vital role in information security. While the chaotic maps have a long history of researching as a nonlinear dynamic system, visual encryption is useful for concealing messages in videos and safeguarding private content from unauthorized intrusion .In this Thesis, the compression efficiency of video coding has been improved and minimizing the degradation of video quality. The first proposed algorithm is based on the gradient method for edge detection using the Prewitt filter to determine the texture direction of a block to be predicted in the luminance component of a video frame. To decide either implemented the DC mode or the edge-detection based gradient method to predict block under consideration, a predefined threshold value is used for the homogeneity test of each macro-block. To reduce the Bit Rate of the compressed video, Gaussian pulse modulation is also suggested to the Discrete Cosine Transformation (DCT) components of each macro-block during the coding process. The proposed algorithm is carried out on a luminance component of a set of different YUV video sequences with different resolutions and different quantization parameters. The suggested algorithm is evaluated using different metrics which are Peak Signal to Noise Ratio (PSNR) and bit rate measured by Bjontegaard Delta method. The simulation results show the ability of the proposed algorithm in enhancing the BDPSNR averagely by 1.14 dB and reducing the BDBR averagely by 11.34%for QCIF sequences compared to the existing state-of-the-art fast intra-prediction mode.decision algorithms . Two new proposed algorithms for compressed videos by the advanced H.264/AVC video coding also are presented. First algorithm approach has been implemented by robust video encryption algorithm based on the chaos maps with random key to be tested under different attacks. The second algorithm approach has been implemented by using the hybrid of both steganography and cryptography based on chaotic maps for video frames. The proposed algorithms are conducted on luminance component Y of a set of different YUV video sequences with different resolution using MATLAB software. The simulation results of the proposed algorithms are evaluated using various performance metrics comparing to that with the state-of-art techniques. The suggested approaches have shown to be more resistant to many sorts of attacks and is recommended for future using in real-time applications.