Information Technology Reference
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J PG quality %
Fig. 4. Plot of the dependence between the quality of steganography noisy channel (distorted by
JPEG 1 of different quality) added intentional distortion ( JPEG 2) for segmentation blocks of
size 8 × 8 and BER
Source
100
90
80
Fig. 5. Plot of the dependence between the quality of steganography channel (distorted by
JPEG 1) added intentional distortion ( JPEG 2) for segmentation blocks of size 12 × 12 and BER
While comparing the plots presented in Fig. 4 and in Fig. 5, one can see that the re-
sult of collateral effects of the noisy channel and intentional distortion is nonlinear.
Indeed, the averaged BER value resulted from the steganography channel distortion,
say, corresponding to 80% quality of JPEG compression, is significantly less than
BER corresponding to application of two JPEG compressions (channel noise and
intentional distortion) both of quality 90%. One more observation resulted from the
simulation is that the detrimental effect of the intentional distortion (second JPEG ) on
the embedded information decreases with the increase of the block size.
 
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