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Full text of "EMD Techniques of Image Steganography A Comparative
Study
"
See other formats
INTERNATIONAL JOURNAL OF TECHNOLOGICAL EXPLORATION AND LEARNING (IJTEL)
www.ijtel.org
EMD Techniques of Image Steganography
A Comparative Study
Mamta Kalra, Parvinder Singh
Department of Computer Science & Engineering
Deenbandhu Chhoturam University of Science & Technology
Abstract — Exploiting Modification Direction (EMD) is a
technique to hide secret data into digital images. This paper
reviews different EMD techniques to hide the confidential data.
The main idea of EMD is to embed secret data into digital image
in such a way that it provides high embedding efficiency as
compared to the other techniques. The brief introduction of
various EMD schemes and their comparisons are presented in
this paper.
Keywords- Steganography, Exploiting Modification Direction
(EMD), Stego image.
I. Introduction
Since the rise of internet secure data transmission has been
a significant problem. The early approach was to secure
communications is via data encryption. In data encryption, the
content of the message is kept secret whereas sometimes the
existence of message is also need to be kept secret. The
technique used to implement this is called steganography.
Steganography is a technique for hiding secret message into
some other medium in such a way that no one can detect the
existence of the hidden message. The word steganography is
basically derived from two Greek words [1]: Steganos and
Graphie, which means covered writing. Therefore
steganography is a technique of hiding secret and confidential
message in another media such that no one apart from the
intended recipient can even detect the presence of the hidden
message.
The main goal of the steganography is to hide messages
inside other messages in such a way that it does not allow any
eavesdroppers and attacker to even detect that there is a second
secret message present inside that message [2-12].
One way for improving security of the Steganographic
system is to reduce the amount of changes inttoduced in the
cover object due to embedding secret data i.e. increasing the
embedding efficiency of the Steganographic system. Various
techniques were designed for this purpose. EMD(Exploiting
Modification direction) is one those Steganographic techniques
that leads to higher embedding efficiency as compared to other
techniques such as run length encoding [13] and matrix
encoding [14].
EMD is a method of steganography embedding in digital
images in which each secret digit in (2n+l)-ary notational
system is carried by n cover pixels and only one cover pixel is
either increased by one or decreased by one or remain same. In
general, for each group of n cover pixels there are 2n possible
ways of alteration. These 2n ways of modification and one case
in which no pixel is changed form (2n + 1) different values of a
secret digit. The direction of modification of cover pixel is
fully exploited that's why it achieves high embedding
efficiency as compared to other techniques.
Various modifications of EMD are also designed which are
given in this paper. The rest of the paper is organized as
follows: In section II, concepts of EMD scheme has been
explained. Various EMD techniques have been explained and
compared in section III. In section IV, the complete paper is
concluded.
II. EXPLOITING MODIFICATION DIRECTION
TECHNIQUE
Zhang et al [15] proposed a data hiding method that
exploits the modification directions called EMD technique that
is used to convert binary secret data into secret digits(d) in
(2n+l)-ary notational system such that n pixels can be used to
carry one secret digit. In this technique, secret message is
firstly converted into secret digits in (2n+l)-ary notational
system and then each secret digit are embedded into pixel
group (gi,g2, ,g n )- To embed secret digit d, value of
extraction function f e is calculated by using (1).
fei9v92.--.9n) = (g 1 xl + g 2 x2 + - + g n x
nmod (2n+l) (1)
If the value of f e is not equal to the secret digit d, only one
of the pixels from the pixel group has to be incremented or
decremented by one. If both the values are same, then there is
no need to change any pixel. And the process is repeated until
no secret digit is left.
In the extraction procedure, same equation is used for each
pixel group (gi,g2, ,g n ) to find out the secret digits and then
all the secret digits are converted back into binary notation
from (2n+l)-ary notation to find out the secret message.
Fig.l. shows the exttaction function matrix for simplest
case of n=2, where each square is labeled with its extraction
value f e and the f e value of each square and its 2n neighbors are
mutually different. After that each secret digit will be mapped
to a group. If the value of secret digit d and exttaction value f e
are same then no change is required in the group. But both are
not same, value of r is calculated using (2). If r 2.
In this scheme, k (=[log 2 m 2 J ) bits secret message are
embedded into a block of 2 cover pixel (x ; , x i+1) by increasing
or decreasing Xj or/and Xi+i at most by r (=[m/2j known as
searching radius) or remaining same to attain the stego pixel
pair.
In order to achieve high security, two steps of image
blocking are used in this technique and in each step; image is
divided into further sub-images. And a random number,
generated by a pseudo random number generator using secret
key, is used to select the random sub-images for embedding
data. In this way, the data is hidden in different parts of the
image and the intended recipient that knows the secret key will
be able to extract the hidden message.
A new parameter, known as Data Pattern Modifier (DPM)
which is a positive integer lies between 0 to (2 n -l) is defined in
this scheme. Once the value of this parameter is initialized, it is
converted into k bit binary sequence and is used to define 2
new parameters i.e. XORP (XOR Pattern) and XNORP
(XNOR Pattern).
During embedding, k bits of secret message are first
converted into decimal number d and value of extraction
function f is calculated using (11). If both values are same then
no changes are required in pixel values. If values are not same
then a new pair value is selected from searching area defined
via W(2xi+i, 2xr+i)(m, (x i; Xi+i), r) having f value same as d. But
the selected pair may not provide optimal solution with
minimum distortion therefore other pairs are also searched
from the searching area W with center as the selected pair and
the pair having minimum distortion will be selected and the
final stego image pair will be modified with that value. This
process is repeated until the entire message is not embedded
into the cover image.
At the receiver side, the specified embedding pattern for
each block is needed to extract the secret message. For this
purpose, a 2 bit binary key is assigned to each embedding
block by the sender.
Therefore the intended recipient having that secret pattern,
will only be able to extract message from the stego image.
G. Optimized EMD:
In 2010, Lin et al [24] proposed optimize EMD technique
that is based on the relationship between n and payload value.
In EMD scheme, a group of n pixels are used to embed a secret
digit in (2n+l)-ary notational system. The value of n has to be
selected carefully because it will decide the amount of pixel
group and payload for that group. If the value is selected too
large, then it will not provide the enough space to embed the
entire secret message whereas if the value is too small, then it
will use more numbers of pixels to embed data more than it
actually required. So Lin et al in [22] analyze the relationship
between payload and n which is defined by (12).
TABLE III.
Summary of various EMD Techniques
Cr2
a
a
N
O
CQ
CM
o
3
C
C
Advantages
Embedding
efficiency and
embedding rate are
more than run length
encoding and matrix
encoding.
Stego image quality
is also good.
Embedding capacity
is more than basic
EMD.
Embedding rate is
1.5 times as
compared to basic
EMD.
Embedding capacity
is 2 times as
compared to basic
EMD.
Stego image quality
is also good.
No need of message
conversion hence
less time for
embedding.
Stego image quality
is also good.
Embedding capacity
is also high.
Disadvantages
Less efficient.
Safety issues are
there.
Message needs to
be converted into
another format
hence more time
is required for
embedding.
Embedding
capacity is
limited.
Safety issues are
there.
More time for
embedding.
Due to high
embedding
capacity PSNR
value decreases.
Safety issues are
there.
Safety issues are
there.
[y X [log 2 (2n + 1)1 > p (12)
Where I s means the total number of pixels in the cover
image, n means total number of pixels in a group and p means
length of the payload. Since both p and I s are known, hence the
maximum value of n can be calculated easily which provides
the optimal solution.
IJTEL, ISSN: 2319-2135, VOL.3, NO.2, APRIL 2014
388
INTERNATIONAL JOURNAL OF TECHNOLOGICAL EXPLORATION AND LEARNING (IJTEL)
www.ijtel.org
O
CO
a
rs
-C
U
e
_ N
On
O
C
CM
On
O
C
c
C
In improved version
of high capacity
EMD technique, data
embedding strategy
is fast.
In generalized high
capacity EMD
technique, less
storage is required.
Both techniques
provide high
embedding capacity
and security.
Provides high
security.
Stego image quality
is also good.
• Provides low
distortion and high
PSNR value.
• Provides high
security.
• Embedding capacity
is also high
In improved
version of high
capacity EMD
technique, more
storage is
required to store
tables.
In generalized
high capacity
EMD technique,
more time is
required to embed
data.
Does not utilize
all dry pixels to
embed secret
data.
• Embedding
capacity
limited.
Stego image
quality is not so
good.
IV. CONCLUSION
In this paper, we have discussed different EMD techniques
to hide secret data inside the image. EMD techniques provide
better embedding efficiency and embedding rate as compared
to matrix encoding and run length encoding. EMD technique
proposed in [16] improves the 1.5 times embedding capacity as
compared to basic EMD which was further improved in [17].
Generalized EMD, IEMD and scheme proposed in [21] provide
similar image quality and embedding capacity, but in
Generalized EMD scheme there is no need of message
conversion hence less time is required for embedding process
as compared to IEMD. Among all the EMD schemes,
Optimized EMD provides the highest PSNR ratio.
ACKNOWLEDGMENT
The work in this paper is funded by Major UGC Project
"Department of a model for secured Communication".
REFERENCES
[I] Rengarajan Amirtharajan, John Bosco Balaguru Rayappan, "An
intelligent chaotic embedding approach to enhance stego-image quality",
Information Sciences 193, pp. 115-124, journal homepage:
www.elsevier.com/locate/ins, 2012.
[2] Parvinder Singh, Sudhir Batra, H R Sharma, "Message Hidden in 6th
and 7th Bit", Proceedings of International Conference on Controls,
Automation and Communication System, Dec. 22-24, 2004, Allied
Publishers, pp-28 1-284.
[3] Parvinder Singh, Sudhir Batra, HR Sharma, "Evaluating the
Performance of Message Hidden in 1st and 2nd Bit Plane", WSEAS
Transactions on Information Science and Applications, issue 8, vol 2,
August 2005, pp 1220-1227.
[4] Parvinder Singh, Sudhir Batra, HR Sharma, "Message Hidden in 1st and
2nd Bit Plane", Proceedings of 9th WSEAS International Conference on
Computers, Athens, Greece, July 14-16, 2005, pp 1-5.
[5] Parvinder Singh, Sudhir Batra, H R Sharma, "Steganographic Methods
Based on Digital Logic", 6th International Conference on Signal
Processing, Dallas, USA, March 22-24,2007.
[6] Prince Kumar Panjabi, Parvinder Singh, "An Enhanced Data Hiding
Approach using Pixel Mapping Method with Optimal Substitution
Approach", International Journal of Computer Applications, vol. 74(10),
July 2013, pp. 36-43.
[7] Parvinder Singh, Sudhir Batra, HR Sharma, "Hiding Credentials in
Biological Images", A & B Research, vol 22(1), Jan 2006, ISSN 0970-
1970, pp 22-25.
[8] Sonam Chhikara, Parvinder Singh, "SBHCS: Spike based Histogram
Comparison Steganalysis Technique", International Journal of Computer
Applications, vol.75, 2013.
[9] Sudhir Batra, Parvinder Singh, "A Class of $ q $-ary 2-IPP Codes",
Journal of Informatics and Mathematical Sciences 5 (2), 65-76.
[10] Parvinder Singh, Sudhir Batra, HR Sharma, "A review of digital
signatures and status in India", WSEAS Transactions on Computers 4
(4), 408-410.
[II] Jasvinder Kaur, Manoj Duhan, Ashok Kumar, "Digital Logic
Embedding Using Single Row." International Journal on Computer
Science & Engineering, vol. 3, no. 12 , 2011.
[12] Currie, D.L. & Irvine, C.E., "Surmounting the effects of lossy
compression on Steganography", 19 1 ' 1 National Information Systems
Security Conference, 1996.
[13] X. Zhang and S. Wang, "Dynamically running coding in digital
steganography," IEEE Signal Processing Lett., vol. 13, no. 3, pp. 165-
168, Mar. 2006.
[14] A. Westfeld, "F5: a steganographic algorithm," in Proc. 4th Int.
Workshop Information Hiding, Lecture Notes in Computer Science, vol.
2137, pp. 289-302,2001.
[15] X. Zhang and S. Wang, "Efficient Steganographic Embedding by
Exploiting Modification Direction," IEEE Communications Letters, vol.
10, no. 11, pp. 781-783, November 2006.
[16] Chin-Feng Lee, Yi-Ren Wang and Chin-Chen Chang, "A steganography
method with high capacity by improving Exploiting Modification
Direction" IIHMSP, Volume 1 , pp.497 - 500, 2007.
[17] Jin-Yong Byun, Ki-Hyun Jung and Kee-Young Yoo, "Improved Data
Hiding Method by Exploiting Modification Direction", International
Symposium on Ubiquitous Multimedia Computing, pp. 264-266, 2008.
[18] Chin-Chen Chang, Zhi-Hui Wang, Yi-Hui Chen and Ming-Chu Li, "A
Wet Image Data Hiding Scheme Based on Coordinate Modifications"
Third International Symposium on Intelligent Information Technology
Application, 2009.
[19] Fridrich, J., Goljan, M., Lisonek, P. and Soukal, D., "Writing on wet
paper," IEEE Transactions on Signal Processing, vol. 53, no. 10, pp.
3923-3935,2005.
[20] Due, K, Chang, C. C, "A steganographic scheme by fully exploiting
modification directions," Technique Report of Feng-Chia University.
[21] C. N. Shyi, S. H. Kuo and W. C. Kuo, "Data Hiding Method Based on
High Embedding Capacity by Improving Exploiting Modification
Direction" 2008 Conference on Global Logistic Management and
Industry Practice Research. 25, pp.455-462, December 2008.
[22] Wen-Chung, Kuo Jiin-Chiou Cheng, Chun-Cheng Wang, "More
Efficient Steganoraphic Embedding and Capacity-Improvement by
Generalized Exploiting Modification Direction Method" Fourth
IJTEL, ISSN: 2319-2135, VOL.3, NO.2, APRIL 2014
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INTERNATIONAL JOURNAL OF TECHNOLOGICAL EXPLORATION AND LEARNING (IJTEL)
www.ijtel.org
International Conference on Innovative Computing, Information and
Control, 2009.
[23] Hamzeh Hajizadeh, Ahmad Ayatollahi and Sattar Mirzakuchaki, "A
New High Capacity and EMD-based Image Steganography Scheme in
Spatial Domain", 2013.
[24] Kai Yung Lin, Wien Hong, Jeanne Chen, Tung Shou Chen, Wen Chin
Chiang, "Data Hiding by Exploiting Modification Direction Technique
Using Optimal Pixel Grouping" 2nd International Conference on
Education Technology and Computer (ICETC),2010.
IJTEL, ISSN: 2319-2135, VOL.3, NO.2, APRIL 2014
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