1. 1 Image Integrity and Correction Using Parities of Error Control Coding By Jaejin Lee and Chee Sun Won Presented by Du-Xiao Cai S9056031@cs.nchu.edu.tw IEEE International Conference on Multimedia and Expo (III) 2000

2. 2 Outline Introduction Watermark Encoding Authentication and Correction ECC for the Watermark Sequence Experimental Results Conclusions Comments

3. 3 Introduction Adopt ECC technique to generate the watermark. The scrambling key 1. Increase the correction capability. 2. Used as a key for the authentication.

4. 4 Watermark Encoding

5. 5 Authentication and Correction

6. 6 ECC for the Watermark Sequence Reed-Solomon(RS) 1. A Reed-Solomon code is specified as RS(n,k) with s-bit symbols. n = 2 s – 1 2. Can correct up to t symbols,2t=n-k N=2 8 -1=255 T=11 K=255-22(2t) =233

7. 7 ECC for the Watermark Sequence

8. 8 Experimental Results

9. 9 Conclusions Watermarking sequence can be used for correction of illegal modifications. RS technique. Scrambling key used for authentication and increase the correction capability indirectly.correction capability

10. 10 Comments 1. Invisible but not undeletable. 2. Not resistant to lossy data compression. 3. Important information require more RS parity bytes,but not.