1. C M S 2001 Darmstadt 1 Optimization of Watermarking Performances using Error Correcting Codes and Repetition S.Zinger, Z.Jin, B.Sankur*, H. Maître Ecole Nationale Supérieure des Télécommunications 46, rue Barrault, 75634 Paris Cedex 13, France {zinger, jin, maitre}@tsi.enst.fr * Boğaziçi University 80815 Bebek - Istanbul, Turkey sankur@boun.edu.tr S.Zinger, Z.Jin, B.Sankur*, H. Maître

2. C M S 2001 Darmstadt 2 The goal to explore applying coding methods for watermarking purposes robustness the length of the signature the length of the coded word

3. C M S 2001 Darmstadt 3 The constraints : imperceptibility robustness capacity w ~ 10 - 100 bits c ~ 200 - 500 bits

4. C M S 2001 Darmstadt 4 Capacity is the maximum amount of bits which can be hidden in an image Ramkumar, 1998 Servetto, 1998 Barni, 1999 Marvel, 1999 Lin, 2001 Sugihara, 2001

5. C M S 2001 Darmstadt 5 Coding methods Repetition ECC BCH codes Hybrid coding original watermark binary symmetric channel extracted watermark ? attacks

6. C M S 2001 Darmstadt 6 Repetition Bit error probability after repetitions Probability of error for a signature of bits

7. C M S 2001 Darmstadt 7 BCH codes Standard BCH codes, BCH codes by parts BCH codes with subtraction

8. C M S 2001 Darmstadt 8 Examples of BCH codes Capacity bits, payload bits Standard BCH codes code (255,37,45) BCH codes by parts (127,15,27) BCH codes with subtraction (500,38,93)

9. C M S 2001 Darmstadt 9 Hybrid coding BCH coding after repetition repetition after BCH

10. C M S 2001 Darmstadt 10 A comparison of performances Channel error rate is 5%, capacity is 350 bits Hybrid coding Repetition BCH with subtraction

11. C M S 2001 Darmstadt 11 Average of performances Channel error rate is 5% Hybrid coding Repetition BCH with subtraction for capacity

12. C M S 2001 Darmstadt 12 Average of performances Channel error rate is 15% Hybrid coding for capacity Repetition

13. C M S 2001 Darmstadt 13 Average of performances Channel error rate is 30% Hybrid coding Repetition for capacity

14. C M S 2001 Darmstadt 14 The best coding strategy Repetition Shannon capacity Hybrid coding BCH with subtraction for

15. C M S 2001 Darmstadt 15 Connection between channel error rate and JPEG compression rate