156 research outputs found
Region-Based Watermarking of Biometric Images: Case Study in Fingerprint Images
In this paper, a novel scheme to watermark biometric
images is proposed. It exploits the fact that biometric
images, normally, have one region of interest, which represents
the relevant part of information processable by most of the
biometric-based identification/authentication systems. This proposed
scheme consists of embedding the watermark into the
region of interest only; thus, preserving the hidden data from
the segmentation process that removes the useless background
and keeps the region of interest unaltered; a process which can
be used by an attacker as a cropping attack. Also, it provides
more robustness and better imperceptibility of the embedded
watermark. The proposed scheme is introduced into the optimum
watermark detection in order to improve its performance. It is
applied to fingerprint images, one of the most widely used and
studied biometric data. The watermarking is assessed in two
well-known transform domains: the discrete wavelet transform
(DWT) and the discrete Fourier transform (DFT). The results
obtained are very attractive and clearly show significant improvements
when compared to the standard technique, which
operates on the whole image. The results also reveal that the
segmentation (cropping) attack does not affect the performance
of the proposed technique, which also shows more robustness
against other common attacks
A constructive and unifying framework for zero-bit watermarking
In the watermark detection scenario, also known as zero-bit watermarking, a
watermark, carrying no hidden message, is inserted in content. The watermark
detector checks for the presence of this particular weak signal in content. The
article looks at this problem from a classical detection theory point of view,
but with side information enabled at the embedding side. This means that the
watermark signal is a function of the host content. Our study is twofold. The
first step is to design the best embedding function for a given detection
function, and the best detection function for a given embedding function. This
yields two conditions, which are mixed into one `fundamental' partial
differential equation. It appears that many famous watermarking schemes are
indeed solution to this `fundamental' equation. This study thus gives birth to
a constructive framework unifying solutions, so far perceived as very
different.Comment: submitted to IEEE Trans. on Information Forensics and Securit
Spread spectrum-based video watermarking algorithms for copyright protection
Merged with duplicate record 10026.1/2263 on 14.03.2017 by CS (TIS)Digital technologies know an unprecedented expansion in the last years. The consumer can
now benefit from hardware and software which was considered state-of-the-art several years
ago. The advantages offered by the digital technologies are major but the same digital
technology opens the door for unlimited piracy. Copying an analogue VCR tape was certainly
possible and relatively easy, in spite of various forms of protection, but due to the analogue
environment, the subsequent copies had an inherent loss in quality. This was a natural way of
limiting the multiple copying of a video material. With digital technology, this barrier
disappears, being possible to make as many copies as desired, without any loss in quality
whatsoever. Digital watermarking is one of the best available tools for fighting this threat.
The aim of the present work was to develop a digital watermarking system compliant with the
recommendations drawn by the EBU, for video broadcast monitoring. Since the watermark
can be inserted in either spatial domain or transform domain, this aspect was investigated and
led to the conclusion that wavelet transform is one of the best solutions available. Since
watermarking is not an easy task, especially considering the robustness under various attacks
several techniques were employed in order to increase the capacity/robustness of the system:
spread-spectrum and modulation techniques to cast the watermark, powerful error correction
to protect the mark, human visual models to insert a robust mark and to ensure its invisibility.
The combination of these methods led to a major improvement, but yet the system wasn't
robust to several important geometrical attacks. In order to achieve this last milestone, the
system uses two distinct watermarks: a spatial domain reference watermark and the main
watermark embedded in the wavelet domain. By using this reference watermark and techniques
specific to image registration, the system is able to determine the parameters of the attack and
revert it. Once the attack was reverted, the main watermark is recovered. The final result is a
high capacity, blind DWr-based video watermarking system, robust to a wide range of attacks.BBC Research & Developmen
Enhancement of Security of Digital Data with Steganography Technique
In this era of Internet and Technology there is a need to secure digital data from unauthorized users. This can be done with the use steganography techniques. The selling of softwares in the form of digital images and video sequences is very much enhanced due to the cost effectiveness and improvement in technology. But this digital are also at risk to accidental attacks. Nowadays the most important concern is the protection of digital data and therefore it is gaining interest among researchers. The storing and transferring of digital data, needs many security concerns that are sensitive and if this data is lost, counterfeited, or hacked, it may be impossible to recover. The security of this transmitted data can be increased by the application of steganography techniques. In this the digital data can be hidden in the host image and this image is transferred to the receiving end instead of the actual software data. Then by using a secret key, the hidden data are extracted accurately from the carrier image. The data is hidden in such a way to minimize the degradation of actual data. In this paper a method is described to handle attacks on the carrier image
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