829 research outputs found
A Non-Blind Watermarking Scheme for Gray Scale Images in Discrete Wavelet Transform Domain using Two Subbands
Digital watermarking is the process to hide digital pattern directly into a
digital content. Digital watermarking techniques are used to address digital
rights management, protect information and conceal secrets. An invisible
non-blind watermarking approach for gray scale images is proposed in this
paper. The host image is decomposed into 3-levels using Discrete Wavelet
Transform. Based on the parent-child relationship between the wavelet
coefficients the Set Partitioning in Hierarchical Trees (SPIHT) compression
algorithm is performed on the LH3, LH2, HL3 and HL2 subbands to find out the
significant coefficients. The most significant coefficients of LH2 and HL2
bands are selected to embed a binary watermark image. The selected significant
coefficients are modulated using Noise Visibility Function, which is considered
as the best strength to ensure better imperceptibility. The approach is tested
against various image processing attacks such as addition of noise, filtering,
cropping, JPEG compression, histogram equalization and contrast adjustment. The
experimental results reveal the high effectiveness of the method.Comment: 9 pages, 7 figure
Robust Audio Watermarking Against the D/A and A/D conversions
Audio watermarking has played an important role in multimedia security. In
many applications using audio watermarking, D/A and A/D conversions (denoted by
DA/AD in this paper) are often involved. In previous works, however, the
robustness issue of audio watermarking against the DA/AD conversions has not
drawn sufficient attention yet. In our extensive investigation, it has been
found that the degradation of a watermarked audio signal caused by the DA/AD
conversions manifests itself mainly in terms of wave magnitude distortion and
linear temporal scaling, making the watermark extraction failed. Accordingly, a
DWT-based audio watermarking algorithm robust against the DA/AD conversions is
proposed in this paper. To resist the magnitude distortion, the relative energy
relationships among different groups of the DWT coefficients in the
low-frequency sub-band are utilized in watermark embedding by adaptively
controlling the embedding strength. Furthermore, the resynchronization is
designed to cope with the linear temporal scaling. The time-frequency
localization characteristics of DWT are exploited to save the computational
load in the resynchronization. Consequently, the proposed audio watermarking
algorithm is robust against the DA/AD conversions, other common audio
processing manipulations, and the attacks in StirMark Benchmark for Audio,
which has been verified by experiments.Comment: Pages 2
Robust Object-Based Watermarking Using SURF Feature Matching and DFT Domain
In this paper we propose a robust object-based watermarking method, in which the watermark is embedded into the middle frequencies band of the Discrete Fourier Transform (DFT) magnitude of the selected object region, altogether with the Speeded Up Robust Feature (SURF) algorithm to allow the correct watermark detection, even if the watermarked image has been distorted. To recognize the selected object region after geometric distortions, during the embedding process the SURF features are estimated and stored in advance to be used during the detection process. In the detection stage, the SURF features of the distorted image are estimated and match them with the stored ones. From the matching result, SURF features are used to compute the Affine-transformation parameters and the object region is recovered. The quality of the watermarked image is measured using the Peak Signal to Noise Ratio (PSNR), Structural Similarity Index (SSIM) and the Visual Information Fidelity (VIF). The experimental results show the proposed method provides robustness against several geometric distortions, signal processing operations and combined distortions. The receiver operating characteristics (ROC) curves also show the desirable detection performance of the proposed method. The comparison with a previously reported methods based on different techniques is also provided
Medical Image Watermarking using 2D-DWT with Enhanced security and capacity
Teleradiology enables medical images to be transferred over the computer
networks for many purposes including clinical interpretation, diagnosis,
archive, etc. In telemedicine, medical images can be manipulated while
transferring. In addition, medical information security requirements are
specified by the legislative rules, and concerned entities must adhere to them.
In this research, we propose a new scheme based on 2-dimensional Discrete
Wavelet Transform (2D DWT) to improve the robustness and authentication of
medical images. In addition, the current research improves security and
capacity of watermarking using encryption and compression in medical images.
The evaluation is performed on the personal dataset, which contains 194 CTI and
68 MRI cases
ISWAR: An Imaging System with Watermarking and Attack Resilience
With the explosive growth of internet technology, easy transfer of digital
multimedia is feasible. However, this kind of convenience with which authorized
users can access information, turns out to be a mixed blessing due to
information piracy. The emerging field of Digital Rights Management (DRM)
systems addresses issues related to the intellectual property rights of digital
content. In this paper, an object-oriented (OO) DRM system, called "Imaging
System with Watermarking and Attack Resilience" (ISWAR), is presented that
generates and authenticates color images with embedded mechanisms for
protection against infringement of ownership rights as well as security
attacks. In addition to the methods, in the object-oriented sense, for
performing traditional encryption and decryption, the system implements methods
for visible and invisible watermarking. This paper presents one visible and one
invisible watermarking algorithm that have been integrated in the system. The
qualitative and quantitative results obtained for these two watermarking
algorithms with several benchmark images indicate that high-quality watermarked
images are produced by the algorithms. With the help of experimental results it
is demonstrated that the presented invisible watermarking techniques are
resilient to the well known benchmark attacks and hence a fail-safe method for
providing constant protection to ownership rights
HiDDeN: Hiding Data With Deep Networks
Recent work has shown that deep neural networks are highly sensitive to tiny
perturbations of input images, giving rise to adversarial examples. Though this
property is usually considered a weakness of learned models, we explore whether
it can be beneficial. We find that neural networks can learn to use invisible
perturbations to encode a rich amount of useful information. In fact, one can
exploit this capability for the task of data hiding. We jointly train encoder
and decoder networks, where given an input message and cover image, the encoder
produces a visually indistinguishable encoded image, from which the decoder can
recover the original message. We show that these encodings are competitive with
existing data hiding algorithms, and further that they can be made robust to
noise: our models learn to reconstruct hidden information in an encoded image
despite the presence of Gaussian blurring, pixel-wise dropout, cropping, and
JPEG compression. Even though JPEG is non-differentiable, we show that a robust
model can be trained using differentiable approximations. Finally, we
demonstrate that adversarial training improves the visual quality of encoded
images
A multi-scale image watermarking based on integer wavelet transform and singular value decomposition
Towards Optimal Copyright Protection Using Neural Networks Based Digital Image Watermarking
In the field of digital watermarking, digital image watermarking for copyright protection has attracted a lot of attention in the research community. Digital watermarking contains varies techniques for protecting the digital content. Among all those techniques,Discrete Wavelet Transform (DWT) provides higher image imperceptibility and robustness. Over the years, researchers have been designing watermarking techniques with robustness in mind, in order for the watermark to be resistant against any image processing techniques. Furthermore, the requirements of a good watermarking technique includes a tradeoff between robustness, image quality (imperceptibility) and capacity. In this paper, we have done an extensive literature review for the existing DWT techniques and those combined with other techniques such as Neural Networks. In addition to that, we have discuss the contribution of Neural Networks in copyright protection. Finally we reached our goal in which we identified the research gaps existed in the current watermarking schemes. So that, it will be easily to obtain an optimal techniques to make the watermark object robust to attacks while maintaining the imperceptibility to enhance the copyright protection
PSO Based Lossless and Robust Image Watermarking using Integer Wavelet Transform
In recent days, the advances in the broadcasting of multimedia contents in digital format motivate to protect this digital multimedia content form illegal use, such as manipulation, duplication and redistribution. However, watermarking algorithms are designed to meet the requirements of different applications, because, various applications have various requirements. This paper intends to design a new watermarking algorithm with an aim of provision of a tradeoff between the robustness and imperceptibility and also to reduce the information loss. This approach applies Integer Wavelet Transform (IWT) instead of conventional floating point wavelet transforms which are having main drawback of round of error. Then the most popular artificial intelligence technique, particle swarm optimization (PSO) used for optimization of watermarking strength. The strength of watermarking technique is directly related to the watermarking constant alpha. The PSO optimizes alpha values such that, the proposed approach achieves better robustness over various attacks and an also efficient imperceptibility. Numerous experiments are conducted over the proposed approach to evaluate the performance. The obtained experimental results demonstrates that the proposed approach is superior compared to conventional approach and is able to provide efficient resistance over Gaussian noise, sal
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