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Digital watermarking of low bit-rate advanced simple profile MPEG-4 compressed video

2003; Institute of Electrical and Electronics Engineers; Volume: 13; Issue: 8 Linguagem: Inglês

10.1109/tcsvt.2003.815958

1558-2205

A.M. Alattar, Eugene T. Lin, M.U. Celik,

Chaos-based Image/Signal Encryption

A novel MPEG-4 compressed domain video watermarking method is proposed and its performance is studied at video bit rates ranging from 128 to 768 kb/s. The spatial spread-spectrum watermark is embedded directly into compressed MPEG-4 bitstreams by modifying DCT coefficients. A synchronization template combats geometric attacks, such as cropping, scaling, and rotation. The method also features a gain control algorithm that adjusts the embedding strength of the watermark depending on local image characteristics, increasing watermark robustness or, equivalently, reducing the watermark's impact on visual quality. A drift compensator prevents the accumulation of watermark distortion and reduces watermark self-interference due to temporal prediction in inter-coded frames and AC/DC prediction in intra-coded frames. A bit-rate controller maintains the bit rate of the watermarked video within an acceptable limit. The watermark was evaluated and found to be robust against a variety of attacks, including transcoding, scaling, rotation, and noise reduction.