1. LSB matching revisited
Source: IEEE Signal Processing Letters, vol.
13, no. 5, May 2006, pp
Authors: Jarno Mielikainen
Speaker: Wei-Liang Tai

2. Outline Steganography LSB Replacement LSB Matching The Proposed Method
Experimental Results
Conclusions

3. Steganography
Escape
Alice
Bob
Warden

4. LSB Replacement 1 mi mi+1 120 121 01111000 01111001 xi xi+1 121
Cover image
Secret Message 1 mi
mi+1
120
121 xi
xi+1
121 yi
yi+1

5. LSB Matching 1 mi mi+1 120 121 01111000 01111001 xi xi+1 yi yi+1
Cover image
Secret Message 1 mi
mi+1
120
121 xi
xi+1
120+1=121 ( )
Or 120-1=119 ( )
121 ( ) yi
yi+1

6. The Proposed Method (1/5)
Binary function
Property 1:
Property 2:

7. The Proposed Method (2/5)
120
130 xi
xi+1
120
130 mi
mi+1 yi
yi+1

8. The Proposed Method (3/5)
120
130 xi
xi+1 1
120
131
or 129 mi
mi+1 yi
yi+1

9. The Proposed Method (4/5)
120
130 xi
xi+1 1 mi
mi+1
121
130 yi
yi+1

10. The Proposed Method (5/5)
120
130 xi
xi+1 1 mi
mi+1
119
130 yi
yi+1

12. Experimental Results

13. Conclusions The number of changed pixel values is smaller
It is immune against steganalysis