1. Enhanced images watermarking based on amplitude modulation Image and Vision Computing, 24 (2006), 111 – 119 Authors :T. Amornraksa, K. Janthawongwilai Presenter: 李振祥

2. 2 Outline Introduction Amplitude modulation based watermarking The proposed method Experimental results Conclusions

3. 3 Introduction L (I,j) =0.299R (I,j) +0.587G (I,j) +0.114B (I,j) By balancing watermark bits around the embedding pixel.(preparing process) By properly tuning the strength of embedding watermark. (embedding process) By modifying the methods of pixel prediction. (retrivieval process)

4. 4 Amplitude modulation based watermarking(1/3) Scaling factorLuminance Watermark

5. 5 Amplitude modulation based watermarking(2/3)

6. 6 rewrite Amplitude modulation based watermarking(3/3)

7. 7 The proposed method

8. 8 The proposed method-1 XOR (for watermark)

9. 9 The proposed method-1 0

10. 10 The proposed method-2 Gaussian mask

11. 11 The proposed method-3 Pixel value replacing 657 678 789 777 678 789

12. 12 Experimental results

13. 13 Experimental results

14. 14 Experimental results

15. 15 Experimental results

16. 16 Experimental results

17. 17 Experimental results

18. 18 Experimental results

19. 19 Experimental results

20. 20 Experimental results

21. 21 Experimental results

22. 22 Experimental results

23. 23 Experimental results (Attack)

24. 24 Experimental results (Attack)

25. 25 Experimental results (Attack)

26. 26 Experimental results (Attack)

27. 27 Experimental results (Attack)

28. 28 Experimental results (Attack)

29. 29 Conclusions To improve accuracy and robustness of the watermark can use: Employing an error control coding Multiple embedding techniques