MASTER THESIS Video Watermarking - Computer Graphics Group ...

samples is subtracted from the residual.
Such compensated residual is now ready for direct watermark embedding in
the spatial domain. It depends on particular watermarking method whether the
embedding process is controlled by the residual only or by the predicted samples
as well.
Then, the residual is forward transformed and quantized. Note that the
spatial domain watermark can be impaired by the quantization.
The quantized transform coefficients may be directly watermarked in the
frequency domain.
The coefficients, watermarked either in the spatial domain or in the
frequency domain, are dequantized and inverse transformed again. Such obtained
residual is added (and clipped) to predicted samples from the watermarked
picture to form a block of the watermarked picture.
Figure 11: Watermark element embedding scheme with intra prediction
error compensation
If the samples were not clipped, the reconstruction of the pictures would not
be necessary. The error compensation would be possible by subtracting samples
that are intra predicted from the difference in the residual caused by watermark
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