International Journal Papers

Permanent URI for this collectionhttp://dl.cerist.dz/handle/CERIST/17

Browse

Author: search.filters.author.Bouchama, Samira

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Error Drift Compensation for Data Hiding of the H.264/AVC
    (Romanian Society of Control Engineering and Technical Informatics, 2013) Bouchama, Samira; Hamami, Latifa; Aliane, Hassina
    The error propagation problem is one of the most attractive issues in the field of data hiding of compressed video because the achievement of several data hiding characteristics remains dependant on it. In this paper, a solution to compensate the error propagation is proposed for data hiding of the H.264/AVC. The error compensation is performed by a prior measurement of the introduced error in the watermarked block or in the neighbouring blocks. Two schemes are proposed: The first algorithm exploits the method of watermarking paired-coefficients in each block in order to bring the error to the middle of the block matrix. The distortion caused by each paired-coefficient is calculated in order to give a watermarking priority to the pairs which introduce the minimum error. In the second scheme, the error estimated in the neighbouring blocks is reduced from the residuals during the encoding process. In both schemes, results show that an important improvement of the video quality can be achieved and a good compromise is provided between the video distortion, the bitrate and the embedding.
  • Thumbnail Image
    Item
    Watermarking of H.264 Coded Video Based on the Shifted-Histogram Technique
    (2010-12) Bouchama, Samira; Hamami, Latifa; Qadri, Muhammad Tahir; Ghanbari, Mohammed
    Reversible video watermarking through shifted histogram of the quantized coefficients of the H.264/AVC coded video is introduced. In CIF sequences, the embedded data of a capacity of more than 2500 bits in I frame is possible and can exceed 7000 bits if we also exploit about 10 P frames in the GOP for the embedding. While the degradation introduced by the watermarked can achieve around 13 dB, the subjective impacts are almost negligible. This data hiding is reversible and it increases the encoded bits by less than 1 % and less than the embedding capacity offering the opportunity to carry information at a lower bitrate rather than a second channel.