Ordered bitplane watermarking of digital video by direct sequence spread spectrum
Bijan G. Mobasseri · 2002
Still image watermarking has gained considerable interest. Digital video, however, has received comparatively less attention. In this work we present a formal framework for digital video watermarking. The video signal is modeled as sequence of bitplanes arranged along the time axis. Watermarking of this sequence is a two layer operation. A controlling m-sequence first establishes a pseudorandom order on the bitplanes. This order determines the candidate planes for later watermarking. The watermark itself is a 2D extension of the same or possibly another m-sequence. We have shown that the watermark, when limited to the 4 lowest bitplanes of an 8-bit signal, are unnoticeable. We have also shown that a correlation detector operating over a sequence of frames can extract an embedded watermark at SNR's as low as 0 dB. The watermarked video is also robust to video editing attempts such as subsampling, frame reordering etc. In addition, the watermark is identifiable from arbitrary short segments of video.