1. Improving histogram-based reversible data hiding by interleaving predictive
Source: IET Image Processing, Vol. 4, No. 4, Aug. 2010, pp
Authors : C.-H. Yang and M.-H. Tsai
Speaker : Hon-Hang Chang
Date : 2010/12/01

2. Outline Introduction Related work Proposed method Experiment results
Conclusion

3. - = + = Introduction Histogram Difference Array D Cover image
Predicted image + =
Predicted image
Stego-image
Difference Array D’
Embed the secret bit 0 or 1

4. Related work D D D H Stego-image 62 56 63 60 61 59 58 55 57 x 6 7 3 2
Lin et al.’s method 62 56 63 60 61 59 58 55 57 x 6 7 3 2 1 4 x 7 8 4 3 1 5 x 7 8 4 3 1 2 5
Shift
Embed D D D H
Shift 63 56 64 60 62 59 58 54 55
Stego-image

5. Related work (Cont.) D D D Stego-image H x 7 8 4 3 1 2 5 x 7 8 4 3 1 5
Lin et al.’s method x 7 8 4 3 1 2 5 x 7 8 4 3 1 5 x 6 7 3 2 1 4
Extract
Shift 63 56 64 60 62 59 58 54 55 D D D
Stego-image 62 56 63 60 61 59 58 55 57
Shift H

6. Proposed method H D 5 4 6 3 2 5 1 4 -1 6 -2 3 Embedding in odd columns
D1,1=H1,1-H1,2=5-5=0 5 4 6 3 2 5 1 4 -1 6 -2 3
D1,3=H1,3- ˻(H1,2+H1,4)/2˼
=5- 4= 1
D1,3=H1,5- H1,4
=4- 4= 0 H D
Odd columns (Predicted pixels)
Even columns(Sample pixels)
D’s Histogram

7. Proposed method(Cont.)
Embedding in odd columns 5 1 4 -1 6 -2 3
Podd1=0
Podd2=-1
Zodd1=2
Podd2=-3 D
D’s Histogram 5 2 4 -1 6 -3 3
Shift
Shift D
D’s Histogram after shifting

8. Proposed method(Cont.)
Embedding in odd columns
Embed secret bit 0, no change!!
Secret bits I:
W1,1=W1,2+D1,1=5+0=5
W1,3=˻(W1,2+W1,4)/2˼+D1,3=4+2=6
W1,5=W1,4+D1,5=4+1=5
D’s Histogram after shifting
Embed secret bit 1, changed to Podd2-1 or Podd1+1!! 5 6 4 3 1 5 2 4 -1 6 -3 3 5 2 4 1 -2 6 -1 -3 3
Embed
Stego-image W1 D D

9. Proposed method(Cont.)
Embedding in even columns 5 6 4 3 1
D1,2=H1,2- ˻(H1,1+H1,3)/2˼
=5- 5= 0 5 6 -1 4 3 2 1 -2
D1,4=H1,4- ˻(H1,3+H1,5)/2˼
=4-5=-1 W1 D
Odd columns (Sample pixels )
Even columns(Predicted pixels)
D’s Histogram

10. Proposed method(Cont.)5 6 -1 4 3 2 1 -2
Embedding in even columns
Shift
Shift
Podd1=2
Podd2=-1
Zodd1=4
Zodd2=-3 D
D’s Histogram 5 6 -1 4 3 2 1 -3 D
D’s Histogram after shifting

11. Proposed method(Cont.)
Embedding in even columns
Embed secret bit 0, no change!!
Secret bits II: 01101
W1,2=˻(W1,1+W1,3)/2˼+D1,2=5+0=5
W1,4=˻(W1,3+W1,5)/2˼+D1,4
=5+(-1)=4
D’s Histogram after shifting
Embed secret bit 1, changed to Podd2-1 or Podd1+1!! 5 6 4 7 3 1 2 5 6 -1 4 3 2 1 -3 5 6 -1 4 3 1 2 -2 -3
Embed
Stego-image W2 D D

12. Proposed method(Cont.)
D1,2= W1,2 -˻(W1,1+W1,3)/2˼
=5-5=0
D1,4= W1,4 -˻(W1,3+W1,5)/2˼
=4-5=-1
Extracting in even columns 5 6 -1 4 3 1 2 -2 -3 5 6 4 7 3 1 2
Podd1=2
Podd2=-1
D’s Histogram
Zodd1=4
Zodd2=-3
Stego-image W2 D 5 6 -1 4 3 2 1 -2 5 6 4 3 1
D’s Histogram D
Secret bits II: 01101
Stego-image W1

13. Proposed method(Cont.)
D1,1=W1,1-W1,2=5-5=0
D1,3= W1,3 -˻(W1,2+W1,4)/2˼=6-4=2
D1,5=W1,5-W1,4=5-4=1
Extracting in odd columns 5 2 4 1 -2 6 -1 -3 3 5 6 4 3 1
Podd1=0
Podd2=-1
D’s Histogram
Zodd1=2
Zodd2=-3 D
Stego-image W1 5 4 6 3 2 5 1 4 -1 6 -2 3 D H
Secret bits I:
D’s Histogram

14. Proposed method(Cont.)
Other predictive methods
Figure 1 Chessboard with white pixels and black pixels

15. Experiment results
Tabel 1 Compassion between the Lin’s method [4], Lin’smethod [5], Hsiao’s method [8] and our schemes with thechessboard interleaving prediction

16. Experiment results
Table 2 Comparison of capacity, shifting numbers, changing numbers and PSNR values

17. Conclusion The proposed method achieve the larger capacity,
but also keep the image quality better.