28 research outputs found
A Novel DWT-CT approach in Digital Watermarking using PSO
The importance of watermarking is dramatically enhanced due to the promising technologies like Internet of Things (IoT), Data analysis, and automation of identification in many sectors. Due to these reasons, systems are inter-connected through networking and internet and huge amounts of information is generated, distributed and transmitted over the World Wide Web. Thus authentication of the information is a challenging task. The algorithm developed for the watermarking needs to be robust against various attack such as salt & peppers, filtering, compression and cropping etc. This paper focuses on the robustness of the algorithm by using a hybrid approach of two transforms such as Contourlet, Discrete Wavelet Transform (DWT). Also, the Particle Swarm Optimization (PSO) is used to optimize the embedding strength factor. The proposed digital watermarking algorithm has been tested against common types of image attacks. Experiment results for the proposed algorithm gives better performance by using similarity metrics such as NCC (Normalized Cross Correlation value) and PSNR (Peak Signal to Noise Ratio)
Secure and Image Retrieval based on Multipurpose Watermarking for Mammography Images Database
In the cancerology domain, we were brought to make periodic mammography
images to monitor tumor patients. Oracle Database Management system (DBMS) is a
solution to manage these images with patient's data recorder. Knowing the large
size of medical images of mammograms, the Oracle DBMS saves these images
outside the Oracle database using external LOBs. The link between these images
and Oracle is done through the BFILE. At this level, two problems are raised:
the first problem is that access to these images can become impossible because
the link is likely to be broken. The second problem is security, the fact that
the images are saved outside the Oracle database, they do not benefit from its
powerful security. The protection of the integrity and confidentiality of data
and patient images are a necessity defended by laws and they must be preserved
against any unauthorized access, alteration or destruction. In this paper, we
propose the method of reversible watermarking technique based on the difference
expansion to resolve these two problems and explore its use in search and
retrieval strategy of images.Comment: 28-3
Blind Adaptive Watermarking Based on Wavelet Transform and HVS
This paper proposes a novel blind image adaptive watermarking scheme in Discrete Wavelet Transform (DWT) domain for copyright protection or robust tagging applications. Watermarking scheme effectively utilizes the contrast sensitivity model of Human Visual System (HVS) to embed the watermark adaptively without degradation of the original image. Watermark can be extracted without referring to the original image. Simulation results show the robustness of the proposed algorithm against various attacks
Effect of lead oxide on concrete density for radiation shielding purposes
Selection of suitable shielding materials depends on the type, intensity and energy of
radiation source, as well as the shielding properties such as mechanical strength, economic
preparation and resistance to radiation damage. When compared to ordinary concrete, the addition
of some materials with various fractions in the composition of concrete has provided concrete forms
more efficient for gamma ray shielding. Concrete has proven to be an tremendous and adaptable
shielding material with a well-established linear attenuation coefficient for gamma rays and
neutrons. The objectives of this study is to determine the exact composition of concrete constituents
and its density. Concrete samples were prepared by mixing cement, water, aggregate and additive
with different composition and densities. Density was increases by decreasing the aggregates
percent and increasing the additives such as lead oxide. Sample will be compacting to forming a
solid material through pelleting and sintering process. Finally, it will undergo for radiation
attenuation test. It was found that, substitution of lead oxide by aggregate causes increasing in the
specific density and compressive strength of the concrete
Image Watermarking in the Linear Canonical Transform Domain
The linear canonical transform, which can be looked at the generalization of the fractional Fourier transform and the Fourier transform, has received much interest and proved to be one of the most powerful tools in fractional signal processing community.
A novel watermarking method associated with the linear canonical transform is proposed in this paper. Firstly, the watermark
embedding and detecting techniques are proposed and discussed based on the discrete linear canonical transform. Then the Lena
image has been used to test this watermarking technique. The simulation results demonstrate that the proposed schemes are robust
to several signal processing methods, including addition of Gaussian noise and resizing. Furthermore, the sensitivity of the single
and double parameters of the linear canonical transform is also discussed, and the results show that the watermark cannot be
detected when the parameters of the linear canonical transform used in the detection are not all the same as the parameters used
in the embedding progress