1) The document proposes a new image-based data hiding method using reduced difference expansion and integer transform scheme to address challenges with previous methods of low visual quality and low embedding capacity. 2) The new method uses integer transform to compute pixel differences, reduced difference expansion to lessen differences before embedding, and expands pixel blocks to hide secret data. 3) Experimental results on hiding 5KB, 10KB and 20KB of secret data in medical images showed improved PSNR values, and thus visual quality, compared to previous methods, with higher payload capacities.

1. ENHANCING IMAGE-BASED DATA HIDING METHOD USING
REDUCED DIFFERENCE EXPANSION AND INTEGER
TRANSFORM SCHEME
By Maurice Ntahobari
NRP: 5116201702
INSTUTUT TEKNOLOGI SEPULUH NOPEMBER SURABAYA
DEPARTMENT OF INFORMATICS
MASTERS IN NET CENTRIC COMPUTING

2. Background
In this generation of information technology, files
or information sharing between users in remote
have been needs for everyone, anytime and
anywhere.
 Public network that is normally used for such
communication is however unsecure.
The end to end communication must be secured
to maintain integrity and confidentiality

3. Data protection method.
Cryptography
Steganography
Watermarking
Data hiding

4. Cryptography
Secret key encryption Public key encryption
Shared secret key
The same key is used for
both encrypt and decrypt
message
Encrypt DecryptSender Receiver
CiphertextPlaintext
Plaintext
Public Key
Public Key
Key repository
Bob Alice

5. Data hiding processes

6. Image data hiding
Spatial domain data
hiding
Frequency domain
data hiding
Spatial domain datahiding
LSB
modification
Compression
based RDH
Histogram
shifting
Difference
Expansion
hiding
Pixel value
difference
Prediction error
expansion
Transformdomain
DCT DWT IWT

7. Challenges in data hiding
based method
The previous data hiding method based on
reduced difference expansion suffer to two main
problems.
Low visual quality
2 challenges
Low embedding capacity

8. Related work
Difference expansion (Tian)
Reduced difference expansion (Liu)
Improved reduced difference expansion (Yi)
Difference expansion of quads (Alattar)
An improved quad and RDE based medical data
hiding method (Ahmad et al)

9. Integer transform scheme
P0 P1
P2 P3
P0
P1
P2

10. New proposed method
1. Integer transform scheme to compute the
difference between two pixels.
P0 P1
P2 P3

11. New proposed method
2. Reduced difference expansion to reduced
difference before embedding process

12. New proposed method
3. Secret Data Embedding
- Expandable pixel block - Changeable pixel
block

13. New proposed method
4. The new pixel construction

14. New proposed method
3. Tools and dataset
 Medical and common images
Secret message of different size(5kb,10kb,20kb)
Mathlab programming language

15. The results for 5kb embedded
in medical images
Medical images PSNR Value for
Previous method in
(Ahmad, Holil,
Wibisono, & Ijtihadie,
2013)
PSNR value for the
proposed method
Abdominal
Leg
Head
Hand
Chest
Average
37.6805
38.0537
31.9050
37.5609
38.0634
36.6527
38.717
39.135
33.046
38.131
39.686
37.743

16. The results for 10 kb
embedded in medical images
Medical images PSNR Value for Previous
method in (Ahmad, Holil,
Wibisono, & Ijtihadie,
2013)
PSNR value for the
proposed method
Abdominal
Leg
Head
Hand
Chest
Average
37.6781
38.0088
31.9048
37.5563
38.0617
36.6419
38.715
39.137
33.054
38.130
39.685
37.744

17. The results for 20 Kb
embedded in medical images
Medical images PSNR Value for Previous
method in (Ahmad, Holil,
Wibisono, & Ijtihadie,
2013)
PSNR value for the
proposed method
Abdominal
Leg
Head
Hand
Chest
Average
37.6805
38.0537
31.9050
37.5609
38.0634
36.6527
38.717
39.135
33.046
38.131
39.6861
37.743

18. Performance comparison
Lena image Chest image
26
27
28
29
30
31
32
33
5 10 20
ThePSNRvaluesindB
Embedding capacity in kilobyte (kb)
Proposed
method
Previous
method
(Ahmad,
Holil,
Wibisono,
&
Ijtihadie,
2013) 35
36
37
38
39
40
41
42
43
5 10 20
ThePSNRvaluesindecibel(dB)
Embedding capacity in kilobyte (kb)
Proposed
method
Previous
method
(Ahmad,
Holil,
Wibisono,
& Ijtihadie,
2013)

19. Average performance for all medical
Images on different size of secret
messages
35
36
37
38
39
40
41
5 10 20
AveragePSNRvaluesindecibel(dB)
Embedding capacity in kilobyte (kb)
Proposed
method
Previous method
(Ahmad, Holil,
Wibisono, &
Ijtihadie, 2013)

20. Conclusion
1. The visual quality is improved for almost all
images and the performance depends on the
amount of secret data hidden in a specific
image.
2.The visual quality decreases as long as the
embedding capacity increases and the quality of
stego image is directly proportional to the
payload capacity where increasing one entity
decreases another and verse versa.
3. The performance of a data hiding algorithm
depends on the cover image(intensity) used in
embedding process.

21. Thank you very much !!!!!
We love your questions and
comments