1. Using Genetic Algorithm to Embed Important Information in an Image Compression File
Chair Professor Chin-Chen Chang (張真誠)
National Tsing Hua University
National Chung Cheng University
Feng Chia University

2. Introduction Information Hiding Hiding system Stego image Cover image
Secret message

3. Introduction (Cont.) Cover Carriers Image Compression code Video Sound
Text

4. Kim et al.’s Method ： 9 1 2 3 4 5 6 7 8 …

5. Kim et al.’s Method (Embedding)5 8 3 4 7 6 1 2 ： 9 1 2 3 4 5 6 7 8
Cover Image
Cover Image 6 9 7 3 8 1 2 5 4 …
Stego Image
Stego Image

6. Kim et al.’s Method (Embedding)6 9 7 3 8 1 2 5 4 ： 9 1 2 3 4 5 6 7 8
Stego Image
Stego Image …

7. Zhang and Wang’s Method (Embedding)
Extracting function: 8 7 9 4 79 54 55 11 20 21 12 24 10
Secret data: … p2
255 1 2 3 4 1 2 3 4 1 : : : : : : : : : : : : :
10002
1 35 … 11 2 3 4 1 2 3 4 1 2 3 2 … 10 1 2 3 4 1 2 3 4 1
Cover image … 9 3 4 1 2 3 4 1 2 3 4 3 … 8 1 2 3 4 1 2 3 4 1 2 1 … 7 4 1 2 3 4 1 2 3 4 4 … 6 2 3 4 1 2 3 4 1 2 3 2 … 5 1 2 3 4 1 2 3 4 1 7 10 4 … 4 3 4 1 2 3 4 1 2 3 4 3 … 3 1 2 3 4 1 2 3 4 1 2 1 … 2 4 1 2 3 4 1 2 3 4 4 … 1 2 3 4 1 2 3 4 1 2 3 2 … 1 2 3 4 1 2 3 4 1
Stego image 1 2 3 4 5 6 7 8 9 10 11 …
255 p1
Magic Matrix

8. Zhang and Wang’s Method (Extracting)p2 7 10 4
255 1 2 3 4 1 2 3 4 1 : : : : : : : : : : : : : … 11 2 3 4 1 2 3 4 1 2 3 2 … 10 1 2 3 4 1 2 3 4 1 … 9 3 4 1 2 3 4 1 2 3 4 3 … 8 1 2 3 4 1 2 3 4 1 2 1
Stego image … 7 4 1 2 3 4 1 2 3 4 4 … 6 2 3 4 1 2 3 4 1 2 3 2 … 5 1 2 3 4 1 2 3 4 1 … 4 3 4 1 2 3 4 1 2 3 4 3 … 3 1 2 3 4 1 2 3 4 1 2 1 … 2 4 1 2 3 4 1 2 3 4 4
1 35 … 1 2 3 4 1 2 3 4 1 2 3 2 … 1 2 3 4 1 2 3 4 1 p1 1 2 3 4 5 6 7 8 9 10 11 …
255
Extracted secret data: 10002
Magic Matrix

10. Pixels in the Image Block
248 76 49 62 57 24 96
118
125
144 56 41 82 97
211
114

11. Generate Compression Code
248 76 49 62 57 24 96
118
125
144 56 41 82 97
211
114 1
AVERAGE: 100 H L
160 64

12. LSB Data Hiding SECRET 010 100 H L 160 64 H’ L’ 162 68 H L 10100 000 H’ L’
LSB Data Hiding

13. Recovery of the Image Block
160 64
162 68 H L
160 64 H’ L’
162 68

14. Substitution Tables SECRET 010 100 2 4 SECRET ’ 100 110 4 6 Table 1 11 2 3 4 5 6 7
Table 2 1 2 3 4 5 6 7
Table 3 2 1 3 4 5 6 7
Table 40320 7 1 6 2 5 3 4

15. Flowchart of Genetic Algorithm
Initial Mating Pool
Max(Fitness)-Avg(Fitness) <Terminate Threshold
Fitness(Table) SELECTION
Yes
End No
Max(Fitness)-Avg(Fitness) <Threshold
Add 30% New Tables
CROSSOVER 80% MUTATION 0.1% No
Yes

16. Initial Mating Pool Initial Mating Pool Table 1 Table 3 Table 17
Table 1
Table 3
Table 17
Table 323
Table 777
Table 4500
Table 9122
Table 24010
Table 26023
Table 40300

17. Fitness Function = f( ) f( ) f( ) 30 23 5 18 4 9 1 7 2 Fitness(Table)
Fitness(Table)
Table 1
Table 3
Table 17
Table 323
Table 777
Table 4500
Table 9122
Table 24010
Table 26023
Table 40300
f( )
f( )
f( ) = 30 23 5 18 4 9 1 7 2

18. Selection
SELECTION

19. Crossover CROSSOVER 80% Table 1 1 2 3 4 5 6 7 Table 3 2 1 3 4 5 6 71 2 3 4 5 6 7
Table 3 2 1 3 4 5 6 7
Table 1’ 2 1 3 4 5 6 7
Table 3’ 1 2 4 3 5 6 7

20. Mutation
MUTATION 0.1%
Table 1 1 2 3 4 5 6 7
Table 1’ 1 2 6 3 4 5 7

21. Example Initial Mating Pool Yes End Add 30% New Tables1 3 17
323
Fitness 30 23 5 18
Survival Probability
40%
30% 7%
23%
Initial Mating Pool
Max(Fitness)-Avg(Fitness) <Terminate Threshold
Table 1 3
323
Fitness(Table) SELECTION
Terminate Threshold
30 – = 4.75
> 2
Yes
End
Fitness 30 23 18 No
Threshold
30 – = 4.75
< 5
Table 1 3’
777’
Table 1 3
777
Max(Fitness)-Avg(Fitness) <Threshold
CROSSOVER 80% MUTATION 0.1%
Add 30% New Tables No
Yes
Threshold
30 – = 8.25
> 5
Fitness 30 23 4
Table 1
3’’
777’

22. Experimental Results LSB GA ELSB Image PSNR EC Time Lena 31.10 0.375
32.43
2.43
32.68
Tiffany
30.27
31.67
2.57
31.86
Zelda
32.90
34.83
2.68
34.96
Boat
30.33
31.15
2.51
31.35
Barbara
28.25
28.86
2.56
28.92
Baboon
27.06
27.63
27.68
Elaine
31.53
32.91
2.54
32.98
Pepper
31.62
33.02
33.24
Average
30.38
31.56
2.55
31.71
in C language

23. Conclusions
A novel method for embedding secrets in compression code based on GA is presented.
The obtained substitution table is near optimal.
Higher embedding capacity always result in lower stego image quality.