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2. content. We will give an introduction to Rate Distortion theorySome examples will be included. Han Vinck 2012. 3. Fundamental quantity in Information theory . entropy The minimum average number of binary digits needed tospecify a source output (message) uniquely is called SOUR
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1. Introduction to rate-distortion theory A.J. Han Vinck
University of Essen
May 2012
2. 2 content We will give an introduction to Rate Distortion theory
Some examples will be included
Han Vinck 2012
3. 3 Fundamental quantity in Information theory Han Vinck 2012
4. 4 Recall: Express everything in bits 0 and 1 Han Vinck 2012
5. 5 Han Vinck 2012
6. 6 model Han Vinck 2012
7. 7 Rate Distortion Theory Han Vinck 2012 The distortion is a part of the problem
The set of representatives is fixed
The distortion is a part of the problem
The set of representatives is fixed
8. 8 Han Vinck 2012
9. 9 Source representation Han Vinck 2012
10. 10 Source representation I( X; X‘ ) = H(X) – H(X|X‘) = H(X‘) – H(X‘|X)
H(X‘) = I( X; X‘ ) + H(X‘|X) (now H(X‘|X) ? 0)
Hence, minimizing I(X;X‘) for all possible transitions X ? X‘ giving an average
distortion D gives a lower bound R(D) for the representation of X‘ Han Vinck 2012
11. 11 Formal definition The rate distortion function for X and X‘ is formally defined as
Han Vinck 2012
12. 12 Example 1 Han Vinck 2012
13. 13 Example 1: explanation Han Vinck 2012
14. 14 Example 2: binary source Han Vinck 2012
15. 15 Han Vinck 2012
16. 16 Example 2 Han Vinck 2012
17. 17 quantization Han Vinck 2012
18. 18 Quantization for Gaussian X with mean 0 Han Vinck 2012
19. 19 Quantization for uniformly distributed X with mean 0 Han Vinck 2012
20. 20 Han Vinck 2012