1. Lossless Data Hiding in the Spatial Domain for High Quality Images
Source: IEICE Trans. Fundamentals, Vol. E90-A, No. 4, April 2007, pp
Authors: H. L. Jin, M. Fujiyoshi, and H. Kiya

2. Outline Introduction Proposed Algorithm Experimental Results
Conclusions

3. Send Introduction Reversibly Image Steganography Sender Receiver
Secret data: 1001…
Cover image
Secret data: 1001…
Send
Cover image
Stego-image

4. Proposed Algorithm = floor((97+100+100+99+102+100+105+105) /8))=101 g
A pixel 3*3 block b.
each pixel is k=8 bits
Overlapped pixel blocks. b
= floor(( )
/8))=101 g

5. Proposed Algorithm(cont.)
( 2k - 2 = 254)
1. Calculating s : s = the minimum of sb's for all 3x3 blocks.
2. Deciding embeddable blocks:
block b is embeddable if |△b| < s.
3. Embedding: (e.g., secret bit wn = 1 --> gb'= = 100)

6. Proposed Algorithm(cont.)
4. Extraction:
in this case, wn = ( ) mod 2 = 1.
5. Restoration of gb :
in this case, gb = ( )/2 = 100.

7. Results

8. Results(cont.)

9. Results(cont.)

10. Conclusion
A lossless data embedding method in the spatial domain has been proposed.
Only one parameter (the s) needs to be kept.
Improves hidden capacity and stego-image's quality.