ISSN 2319-8885
Vol.03,Issue.33
October-2014,
Pages:6543-6546
www.ijsetr.com
Reversible Watermarking using Difference Expansion Technique
T.SWATHI1, P.AJAY KUMAR REDDY2, DR G.N. KODANDA RAMAIAH2
1
PG Scholar, Dept of ECE, KEC, JNTU Anantapur, Andhrapradesh, India, E-mail: [email protected].
Asst Prof, Dept of ECE, KEC, JNTU Anantapur, Andhrapradesh, India, E-mail: [email protected].
3
HOD, Dept of ECE, KEC, JNTU Anantapur, Andhrapradesh, India.
2
Abstract: In this paper, we are going to survey on data hiding on lossless images using difference expansion method. Reversible
watermarking enables embedding of valuable information in a host signal with no loss of host information. The embedding
ensures the minimization of the mean square error (MSE) and PSNR (peak signal to noise ratio) introduced by watermarking.
This paper proposes to improve the picture clarity and maintain the security and also provides the authentication for our
information. The proposed transform introduces less distortion than the classical prediction-error expansion for complex
predictors such as the median edge detector (MED) or the gradient-adjusted predictor (GAP). It is used for copyright protection,
authentication.
Keywords: DE Difference Expansion, MSE Mean Square Error, GAP Gradient Adjust Predictor, PSNR.
I. INTRODUCTION
Difference expansion (DE) reversible watermarking,
introduced by Tian, It creates space by expanding a
difference. The data and the auxiliary information are further
added to the expanded difference and embedded into the
image. The expanded difference is the one between adjacent
pixels, original and predicted pixels, pixels of a block and the
mean value of the block; pixels of a block and the median
value of the block; and so on. By expanding two times the
difference, one data bit can be embedded. The embedding is
possible if it does not generate overflow or underflow
Embedded bit is extracted and the original pixels are
recovered. The high correlation between image pixels
ensures rather low values for the differences referred above.
Overflow or underflow appears and consequently, high
embedding capacity can be entailed. [1]. This project aims at
reducing the distortion introduced by the watermarking. It is
used for copyright protection, authentication. In application
reversible watermarking is used in military, medical and
source tracking.
(like bank checks) are scanned, protected with an
authentication scheme based on a reversible data hiding, and
sent through the Internet. In most cases, the watermarked
documents will be sufficient to distinguish unambiguously
the contents of the documents.
This enable the decoder extract the watermarking image
and reconstruct the original host image from the watermarked
image. Reversible data-hidings insert information bits by
modifying the host signal, but enable the exact (lossless)
restoration of the original host signal sometimes; expressions
like distortion-free, invertible, lossless or erasable
watermarking are used as synonyms for reversible
watermarking.[2]. In most applications, the small distortion
due to the data embedding is usually tolerable. However, the
possibility of recovering the exact original image is a
desirable property in many fields, like legal, medical and
military imaging. Let us consider that sensitive documents
Compared with other networks, ZigBee has the following
advantages: low power, low cost, short time delay, network
large capacity, reliability and safety.
 MSE (mean square error) <100dB
 PSNR(peak signal to noise ratio)<30dB
II.EXISTING SYSTEM
Existing systems consists of so many disadvantages. As
show in below figure1 is the example for existing system.
While transmitting image from source to destination in the
middle of transmission channel attacks are occurs due to this
attacks our data will insecurity format and it does not having
any authentication. As show in below figure1 is the example
for existing system.
Figure 1. Existing system.
Disadvantages:
There is no copy righting protection,
 No security
 No protection from attacks
 No authentication
Copyright @ 2014 IJSETR. All rights reserved.
T.SWATHI, P.AJAY KUMAR REDDY, DR G.N. KODANDA RAMAIAH
To avoid these problems we are proposing this reversible
1. Pre Processing:
Preprocessing images commonly involves removing lowwater marking scheme using difference expansion technique.
frequency background noise, normalizing the intensity of the
III.PROPOSED SYSTEM
individual particles images, removing reflections, and
In order to avoid the copyright protection, cropping and
masking portions of images. Image preprocessing is the
editing the images, audios & videos. Provide security and
technique of enhancing data images prior to computational
authentication. Protect our images from attacks. Improve
processing.
image clarity, broad casting images without any distortions.
As a basic requirement, the quality degradation on the digital
2. Embedding Processes:
content after data embedding should be low. When the
Embedding the watermark into a define region of interest
information is embedded into images, the pixel value in the
(ROI) by taking the smallest area around an image. This
image will be changed, and thus the image quality is
border will be used for our watermark embedding later. The
degraded. Since the altered pixels cannot be recovered into
watermark generated from hashing the area of interest. The
their original state after the secret messages has been
embedding region is measured to be outside the region of
extracted, permanent distortion will occur. Distortion for
interest as to preserve the area for distortion as a result from
some application is unacceptable, for example chest X-ray
watermarking. In an image, the embedding region‟s pixel
images. For this purpose reversible data hiding is necessary.
value is 0. This feature will be exploited to create a reversible
 Copy right protection
or invertible watermarking.
 Source tacking(different recipients get differently water
Step1: Original image pixel values converted into binary
marked content)
form. Example A is original image
Step 2: key image pixels values also converted to binary
 Broad casting, Video authentication
form. B is the key image
 High Capacity Watermarking achieved by Difference
Step 3: Adding the both binary values with OR operation
Expansion
likes same as matrix addition. By adding both matrix
This enable the decoder extract the watermarking image
obtained matrix is A+B= C where C is water marked image.
and reconstruct the original host image from the
Step4: water marked image look likes same as original image
watermarked image. Reversible data-hidings insert
but image properties of image will be varies.
information bits by modifying the host signal, but enable
the exact (lossless) restoration of the original host signal
Embedding using difference equation
sometimes; expressions like distortion-free, invertible,
 x  b, if di  P and xi  xi 1
lossless or erasable watermarking are used as synonyms for
yi  i
reversible watermarking. In most applications, the small
 xi  b, if di  P and xi  xi 1
(1)
distortion due to the data embedding is usually tolerable.
However, the possibility of recovering the exact original
3. Extraction Process:
image is a desirable property in many fields, like legal,
Reverse process of embedding to extract the key image
medical and military imaging. Let us consider that
and
original image separately. Original image and key image
sensitive documents (like bank checks) are scanned,
will
be reconstructed by extraction process. Original image
protected with an authentication scheme based on a
and
key image is separated by difference expansion
reversible data hiding, and sent through the Internet. In
algorithm.
Here b bit is message bit.
most cases, the watermarked documents will be sufficient
The
message
bit „b‟ can be extracted by
to distinguish unambiguously the contents of the
documents. Proposed system as shown in below figure 2
0, if | y  x | P
i
i 1
b
1,
if
|
y

x
i
i 1 | P  1

(2)
After the secret data gets embedded or hidden in the cover
image, the original cover image will get modification to some
extent with respect to the length of the secret data. At the
receiving end we are not able to get back the original cover
image since our traditional LSB is not providing reversibility.
4. Post Processing:
In digital photography post-production, post-processing or
simply processing refers to work that is done on the digital
files after they have been captured by the camera. The
processing stage is term for all activities after shooting which
lead to the completion of the work.
Examples Image Editors
Figure2. Proposed system.
International Journal of Scientific Engineering and Technology Research
Volume.03, IssueNo.33, October-2014, Pages: 6543-6546
Reversible Watermarking using Difference Expansion Technique
Normally an image file is opened in an image editing
uploading watermark image embedding will perform in
application to change the file and/or improve it. The different
between those images by clicking embedding button after
types of work completed in image editors are too diverse to
completion of embedding click on water mark image then it
discuss in detail. The internet is an excellent distribution
displays water mark image separately If we want extraction
system for the digital media because of its inexpensiveness
image click on extraction then it extracts the watermark
and efficiency. Also the images can be readily shared, easily
image and cover image in separate as shown in figure 3.
used, processed and transmitted which causes serious
problems such as unauthorized use and manipulation of
digital content properties of the three types of reversible
watermarking schemes. Usually, higher embedding capacity
usually comes along with a higher distortion. The watermark
must be able to be easily and securely embedded and
retrieved by the owner. Therefore, the overheads of
embedding process and retrieving process should be limited
in a reasonable range. In Recent years a special kind of
digital watermarking is discussed widely, called reversible
watermarking. It not only provides the protection of the
copyright by embed- ding the assigned watermark into the
original image but also can recover the original image from
the suspected image. The retrieved watermark can be used to
determine the ownership by comparing the retrieved
watermark with the assigned one. Similar to conventional
watermarking schemes, reversible watermarking schemes
have to be robust against the intentional or the unintentional
attacks, and should be imperceptible to avoid the attraction of
Figure3. Generating watermark image.
attacks and value lost.
IV.COMPARISION BETWEEN PROPOSED AND
EXSISTING SYSTEM
Figure4. After clicking extraction button
VI.ADVANTAGES AND APPLICATIONS
A. Copy right protection:
Copy protection, also known as content protection, copy
V. EXPERIMENTAL REULTS
prevention and copy restriction, is any effort designed to
Double click on mat lab and click on file tool open new Mprevent the reproduction of software, films, music, and other
file. Write program on a program on mat lab editor window
media, usually for copyright reasons on Various methods
save that m- file and click debug press run button as After
have been devised to prevent reproduction so will gain
debugging reversible water mark window will be displayed
benefit from each users who obtain a copy of their product.
Click on browser and upload picture or image but image
Unauthorized copying and leading to proposal of anti-piracy
must be in png format After uploading png image (portable
laws such as PIPA. Some methods of copy protection have
network graphics) and making histogram modification on
also led to criticisms because it caused inconvenience for
that image by clicking histogram modification button. After
honest users or secretly installed additional software to watch
International Journal of Scientific Engineering and Technology Research
Volume.03, IssueNo.33, October-2014, Pages: 6543-6546
T.SWATHI, P.AJAY KUMAR REDDY, DR G.N. KODANDA RAMAIAH
activity on user's computer to detect copying. Effective copy
VIII.COUNCLUSION
protection as well as protecting user rights is still an ongoing
In this work, we propose the reversible watermarking
based on prediction error expansion and pixel selection on
problem with media publication.
images. In our proposed system we focus on the flat region to
B. Source tracking: A watermark is embedded into a digital
embed the watermark. The proposed transform introduces
signal at each point of distribution. If a copy of the work is
lower distortions than the one based on high-performance
found later, then the watermark may be retrieved from the
predictors such as MED and GAP. The proposed method
copy and the source of the distribution is known. This
outperforms a representative prior art of Tian‟s DE
technique reportedly has been used to detect the source of
transform, and it is shown that Tian‟s transform is equivalent
illegally copied movies.
to a pre- diction-error expansion of a simple linear predictor
with improved embedding. Practical reversible watermarking
C. Steganographic: In digital steganographic, electronic
algorithms based on the proposed transform have been
communications may include steganographic coding inside
investigated.
of a transport layer, such as a document file, image file,
IX. REFERENCES
program or protocol. Media files are ideal for steganographic
[1]J. Tian, “Reversible data embedding using a difference
transmission because of their large size. For example, a
expansion,” IEEE Trans. Circuits Syst. Video Technol. vol.
sender might start with an innocuous image file and adjust
13, no. 8, pp. 890–896, Aug. 2003.
the color of every 100th pixel to correspond to a letter in the
[2] A. M. Alattar, “Reversible watermark using th difference
alphabet, a change so subtle that someone not specifically
expansion of a generalized integer transform,” IEEE Trans.
looking for it is unlikely to notice it.
Image Process. vol. 13, no. 8, pp. 1147–1156, Aug. 2004.
 Hidden messages within wax tablets in ancient Greece,
[3] L. Kamstra and H. J. A. M. Heijmans, “Reversible data
people wrote messages on the wood, and then covered it
embedding into images using wavelet techniques and
with wax upon which an innocent covering message was
sorting,”IEEE Trans. Image Process. vol. 14, no. 12, pp.
written.
2082–2090, Dec. 2005.
 Hidden messages on messenger's body also used in
[4] D. Coltuc and J.-M. Chassery, “Very fast watermarking
ancient Greece. Herodotus tells the story of a message
by reversible contrast mapping,”
tattooed on the shaved head of a slave of Histiaeus,
[5]IEEE Signa Xiao long Li, Bin Yang Tienyong Zeng
hidden by the hair that afterwards grew over it, and
“Efficient Reversible Watermarking Based on Adaptive
exposed by shaving the head again. The message
Prediction.
allegedly carried a warning to Greece about Persian
invasion plans. This method has obvious drawbacks,
such as delayed transmission while waiting for the
slave's hair to grow, and the restrictions on the number
and size of messages that can be encoded on one
person's scalp.In the early days of the printing press, it
was common to mix different typefaces on a printed
page due to the printer not having enough copies of some
letters otherwise. Because of this, a message could be
hidden using 2 (or more) different typefaces, such as
normal or italic.
D. Video authentication:
By using this digital watermarking scheme we can also
provide authentication for our image .copy right prevention
and copy restriction if any effort to design to prevent the
reproduction of software, films, music, and other media for
copy right reasons. We can make copy right protection on
videos is investigated for the further use with the help of
reversible water marking.
VII FUTURESCOPE
In this project this reversible watermarking using
difference expansion has been done on images .Further this
can be enhanced by applying this on video clips and audio
clips in future. This will be useful to protect our audio and
video clips from unauthorized persons to provide privacy and
security future extension implementing this method in audio,
video files improving the hiding capacity of videos and audio
files.
International Journal of Scientific Engineering and Technology Research
Volume.03, IssueNo.33, October-2014, Pages: 6543-6546