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Embedding Information in Grayscale Images - Signal Processing ...

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1<br />

0.9<br />

0.8<br />

0.7<br />

0.6<br />

0.5<br />

0.4<br />

0.3<br />

0.2<br />

0.1<br />

0<br />

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2<br />

Figure 6: Rate-distortion curve, time-shar<strong>in</strong>g R = 1 LSB modulation (...), b<strong>in</strong>ary Hamm<strong>in</strong>g<br />

codes (o), ternary Hamm<strong>in</strong>g codes (*), the Golay codes (x), and the 5-ary codes (+).<br />

8 Conclusion<br />

We have only looked at small distortions here. Moreover we have concentrated on perfect<br />

codes s<strong>in</strong>ce this was so easy. It can be shown that Hamm<strong>in</strong>g codes are quite good for D → 0.<br />

For a moderate rate we have seen that Golay codes are rather good, but what about even better<br />

codes for even higher rates? How do we generalize the color<strong>in</strong>g results to larger number of<br />

colors and more dimensions?<br />

References<br />

[1] J. Chou, S. Pradhan, L. El Ghaoui and K. Ramchandran, “A Robust Optimization Solution<br />

to the Data Hid<strong>in</strong>g Problem Us<strong>in</strong>g Distributed Source Cod<strong>in</strong>g Pr<strong>in</strong>ciples,” prepr<strong>in</strong>t,<br />

2000.<br />

[2] S. Gelfand and M. P<strong>in</strong>sker, “Cod<strong>in</strong>g for a Channel with Random Parameters”, Problems<br />

of Control and <strong>Information</strong> Theory, vol. 9, pp. 19-31, 1980.<br />

[3] P. Moul<strong>in</strong> and J. O’Sullivan, “<strong>Information</strong>-theoretic Analysis of <strong>Information</strong> Hid<strong>in</strong>g,”<br />

prepr<strong>in</strong>t, 1999.<br />

[4] F.M.J. Willems, ”An <strong>Information</strong>theoretical Approach to <strong>Information</strong> <strong>Embedd<strong>in</strong>g</strong>,”<br />

Proc. 21st Symp. Inform. Theory <strong>in</strong> the Benelux, pp. 255-260, Wassenaar, May 25-26,<br />

2000.

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