26-09-2013, 03:02 PM
Controlled Data Hiding Technique for Color Image Authentication in Frequency Domain
(CDHTCIAFD)
Controlled Data Hiding.pdf (Size: 477.04 KB / Downloads: 36)
Abstract
This paper presents a new steganographic technique
which demonstrates the colour image authentication process in
frequency domain based on the Discrete Fourier Transformation
(DFT). Image authentication is done by hiding secrete
message/image into the transformed frequency component of
source image. The DFT is applied on sub-image block called mask
of size 2 x 2 in row major order. Secrete message/image bit is
fabricated within the transformed real frequency component of
each source image byte except the first frequency component of
each mask. After embedding, a delicate re-adjust phase is
incorporated in the first frequency component of each mask, to
keep the quantum value positive and non fractional in spatial
domain. Robustness is achieved by hiding an authenticating or
secrete message/image in the frequency component with positive
and negatives both quantum values and invisibility is satisfied in
spatial domain using delicate re-adjust phase. Inverse DFT
(IDFT) is performed after embedding to transform embedded
image in frequency domain to spatial domain. Experimental
results conform that the proposed algorithm performs better than
discrete cosine transformation and Quaternion Fourier
Transformation based scheme
INTRODUCTION
Image transmission via the internet face problems such as
information security, copyright protection, Originality etc.
Secured communication is possible with the help of encryption
technique which is a disordered and confusing message that
makes suspicious enough to eavesdroppers. Without creating
any special attention of attackers steganographic methods [1]
overcome the problem by hiding the secrete inforoation into the
source. Image trafficking across the network is increasing day
by day due to the proliferation of internetworking. Image
authentication is needed to prevent unauthorized access in
various e-commerce application areas. This security can be
achieved by hiding data within the image. Data hiding [2, 3, 4,
7] in the image has become an important technique for image
authentication and identification. Therefore, military, medical
and quality control images must be protected against attempts to
manipulations. Generally digital image authentication schemes
mainly falls into two categories-spatial-domain and frequency-
domain techniques. Digital image means the set of pixels which
can be conveniently captured by many electronics devices such
as scanner, camcorder and cameras.
RESULT, COMPARISON and ANALYSIS
This section represents the results, discussion and a
comparative study of the proposed technique CDHTCIAFD
with the DCT-based watermarking method and QFT based
watermarking method in terms of visual interpretation, image
fidelity (IF), and peak signal-to noise (PSNR) analysis and
mean square error (MSE) . In order to test the robustness of
the scheme CDHTCIAFD, the technique is applied on more
than 50 PPM images from which it may be conformed that the
algorithm may overcome various types of attack like visual
attack and statistical attack. The distinguishing of source and
embedded image from human visual system is quite difficult.
In this section some statistical and mathematical analysis is
given. The original source images ‘Baboon’, ‘Sailboat’ are
shown in Fig. 3a and Fig. 3b and 147456 bytes of information
are embedded into each image. The dimension of each source
colour images is 512 x 512 and the dimension of authenticating
colour image is 220 x 220, shown in Fig. 3c. Fig. 3d and Fig.
3e are embedded images using CDHTCIAFD. Two bit of
authenticating information is embedded at any position
between 1st to 4th positions of real part of the frequency
component excluding first component in each mask.
CONCLUSION
CDHTCIAFD technique is an image authentication
process in frequency domain to enhance the security compared
to the existing algorithms. In compare to DCT and QFT based
watermarking technique our algorithm is applicable for any
type of color images and strength is high. First frequency
component in each mask is used for re-adjust as for embedding,
new color may be generated. The control technique is applied
to optimized the noise addition as a result PSNR is increased
with low MSE and IF is nearer to 1. Hence the scheme may be
more robust against brute force attack. In CDHTCIAFD
distortion of image and change of fidelity (like sharpness,
brightness etc) is negligible