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(a) p 1 =0.0, p 2 =1.0, BCR 1 =76.61%, BCR 2 =70.78%
(b) p 1 =1.0, p 2 =0.0, BCR 1 =68.56%, BCR 2 =70.26%
Fig. 12.14. The two extracted watermarks under the case when one channel is total
breakdown, with a codebook size of L = 1024.
Table 12.4. Comparisons of watermarked image quality under different channel
erasure probabilities with a codebook length of L = 1024 after considering the
embedding of two watermarks in Sec. 12.5.1.
PSNR with our
PSNR with [10]
PSNR with [11]
Channel erasure probability
p 1
p 2
method (in dB)
(in dB)
(in dB)
0
0
32.74
31.84
32.20
0.1
0.1
28.35
28.47
28.88
0.25
0.25
24.27
24.33
24.34
0.5
0.5
19.78
19.77
19.79
0
1
25.10
24.88
25.17
1
0
25.04
24.72
25.17
bat with channel noise under both lightly and heavily erased channels. Also,
in comparison with existing VQ-based algorithms in the literature, our al-
gorithm perform better than others in both the watermark imperceptibility,
shown by PSNR, and the watermark robustness, shown by BCR. Therefore,
our algorithm is not only innovative for research, but also suitable for practical
implementation.
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