1. Reversible Data Hiding
Zhicheng Ni, Yun-Qing Shi, Nirwan Ansari, and Wei Su
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY, VOL. 16, NO. 3, MARCH 2006
Reporter : Chien-Ting Kuo
2019/4/9

2. Outline 1. Introduction 2. Proposed Algorithm 3. Experimental Results
4. Conclusions

3. 1. Introduction
A novel reversible data hiding algorithm, which can recover the original image without any distortion from the marked image after the hidden data have been extracted, is presented in this paper.
It can embed more data than many of the existing reversible data hiding algorithms.
This lower bound of PSNR is much higher than that of all reversible data hiding techniques reported in the literature.

4. Lena image: (a) original, and (b) marked (PSNR = 48.2 dB)
Introduction
Lena image: (a) original, and (b) marked (PSNR = 48.2 dB)

6. 2. Proposed Algorithm
generating the histogram

7. 2. Proposed Algorithm modifying selected range
Find Peak point a & Zero Point b
Increase 1 with a-b range value

8. 2. Proposed Algorithm embedding hidden data If Embed 1 :
Keep the value (a+1)
If Embed 0 :
(a+1)  a

9. Proposed Example By Step 1 : Find Peak Point a = 200
230
200
215
210
By Step 1 :
Find Peak Point a = 200
Zero Point b = 230

10. Proposed Example Step 2 : All value between a-b Increase 1 231 201 216
211
Step 2 :
All value between a-b
Increase 1

11. Proposed Example Embedding Binary string
231
201
216
211
If embed value “0”
(a+1) a
If embed value “1”
(a+1) is still (a+1)
a= 200 , a+1 = 201

12. Proposed Example Embedding Binary string
231
200
216
211
201
If embed value “0”
(a+1) a
If embed value “1”
(a+1) is still (a+1)
a= 200 , a+1 = 201

13. Proposed Example Embedding Binary string
231
200
216
211
201
If embed value “0”
(a+1) a
If embed value “1”
(a+1) is still (a+1)
a= 200 , a+1 = 201

14. Proposed Example Embedding Binary string
231
200
216
211
201
If embed value “0”
(a+1) a
If embed value “1”
(a+1) is still (a+1)
a= 200 , a+1 = 201

15. Proposed Example Embedding Binary string
231
200
216
211
201
If embed value “0”
(a+1) a
If embed value “1”
(a+1) is still (a+1)
a= 200 , a+1 = 201

16. Proposed Example (multi pair)

17. Proposed Example (multi pair)
Find a point having a larger histogram value in each of the following three maximum point pairs {h(a1),h(a12)} , {h(a21),h(a23)} , {h(a32),h(a3)}
assume h(a1), h(a23) , h(a3) are the three selected maximum points.
Then {h(a1),h(b1)} , {h(a23),h(b2)} , {h(a3),h(b3)} are the three pairs of maximum and minimum points

18. Proposed Example (multi pair)

19. 4. Experimental Results

20. 4. Experimental Results

26. 5. Conclusion
proposed reversible data hiding technique is able to embed about 5–80 kb into a (512 X 512 X 8) grayscale image while guaranteeing the PSNR of the marked image versus the original image to be above 48 dB.
This algorithm is quite simple, and the execution time is rather short. the computational complexity is
With a computer Intel Celeron 1.4 GHz and the software Matlab 6.5, the total embedding time needed for the Lena image (512 X 512 X 8) is just 100 ms.

27. Q & A