1. Data Hiding Watermarking for Halftone Images
Ming Sun Fu, Student Member, IEEE, and Oscar C. Au, Senior Member, IEEE,
IEEE TRANSACTIONS ON IMAGE PROCESSING, Vol. 11, No. 4, Apr. 2002, pp
Adviser : Dr. Chang, Chin-Chen
Reporter : Huang, Chang-Chin
Date : 2003/03/18

2. Outline
Introduction
Data Hiding without Original Multitone Image (DHST, DHPT, DHSPT)
Data Hiding with Original Multitone Image (DHED, MDHED)
Conclusions

3. Introduction Halftone images Error diffusion
Jarvis kernel and Steinberg kernel

4. Data Hiding without Original Multitone Image (DHST, DHPT, DHSPT)
Data Hiding Self Toggling(DHST)
use seed generate a set of N pseudo-random location.
embedded 0 or 255
simple & error correction coding
“salt-and-pepper” noise
intensity being about 128

5. Data Hiding without Original Multitone Image (DHST, DHPT, DHSPT)
Data Hiding Pair Toggling(DHPT)
slave pixel is chosen randomly.
two errors are introduced instead of one
complexity is slightly larger than DHST
fewer “salt-and-pepper” noise M=

6. Data Hiding without Original Multitone Image (DHST, DHPT, DHSPT)
Data Hiding by Smart Pair Toggling(DHSPT)
Candidate is Min [conafter(m,n)]
Define 2 x0 1 x0

7. Data Hiding without Original Multitone Image (DHST, DHPT, DHSPT)
Data Hiding by Smart Pair Toggling(DHSPT)
Ex. before after
1+2+2= =7 1
X0=1 1
X0=0 -
= 12 +

8. Data Hiding without Original Multitone Image (DHST, DHPT, DHSPT)- -
f(X0, Xmaster) f(X0, Xmaster) = 0
before after
vertical or horizontal master w(i) = 2
 conbefore(m, n) + conafter(m, n) = 10
other master w(i) = 1
 conbefore(m, n) + conafter(m, n) = 11
Xmaster=1
X0=0
Xmaster=0
X0=1 - -

9. Data Hiding without Original Multitone Image (DHST, DHPT, DHSPT)
conbefore= =6
conafter=11-6=5 1
conbefore=0
conafter=10-0=10 1
conbefore=2+2=4
conafter=10-4=6

10. Data Hiding with Original Multitone Image (DHED, MDHED)
Error diffusion

11. Data Hiding with Original Multitone Image (DHED, MDHED)
Error diffusion

12. Data Hiding with Original Multitone Image (DHED, MDHED)
Error diffusion

13. Data Hiding with Original Multitone Image (DHED, MDHED)
Data Hiding Error Diffusion

14. Data Hiding with Original Multitone Image (DHED, MDHED)
Modified Data Hiding Error Diffusion

15. Conclusions

16. Conclusions