617 research outputs found

    Hidden Images

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    Hidden Images of Christ in the Fiction of C.S. Lewis

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    Hidden Images of Christ in the Fiction of C.S. Lewis

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    A SYSTEMATIZED APPROACH TO DATA HIDING USING IMPROVED LSB

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    Aim: This paper mainly focused on introducing a new framework for image and text hiding using a simple Least Significant Bit (LSB) substitution method.  Results: Six 24-bit images are used as reference images. XOR operation is used in the stego key to generate new bit planes of the stego images. An RGB color image is used as a secret cover image. The proposed method dramatically increases the embedding capacity without significantly decreasing the Peak Signal-to-Noise Ratio (PSNR) value.  Conclusion: This method increased the compression ratio, embedding ratio, PSNR and Space 24%, 53%, 36% and 47%, respectively. The result shows that the newly developed method improved the value of accuracy by 30% and sensitivity by 16% for the hidden images.  Keywords: LSB, PSNR, FNR (False Negative Rate), Sensitivity, MSE (Mean Square Error), Specificity HIGHLIGHTS: The newly developed method with simple Least Significant Bit (LSB) improved the accuracy value by 30%, and sensitivity by 16% for the hidden image. The improved LSB method increased security and preserved the quality of hidden images

    On the exact gravitational lens equation in spherically symmetric and static spacetimes

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    Lensing in a spherically symmetric and static spacetime is considered, based on the lightlike geodesic equation without approximations. After fixing two radius values r_O and r_S, lensing for an observation event somewhere at r_O and static light sources distributed at r_S is coded in a lens equation that is explicitly given in terms of integrals over the metric coefficients. The lens equation relates two angle variables and can be easily plotted if the metric coefficients have been specified; this allows to visualize in a convenient way all relevant lensing properties, giving image positions, apparent brightnesses, image distortions, etc. Two examples are treated: Lensing by a Barriola-Vilenkin monopole and lensing by an Ellis wormhole.Comment: REVTEX, 11 pages, 12 eps-figures, figures partly improved, minor revision

    Transmission of hidden images within noise

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    The secure transmission of an image can be accomplished by encoding the image information, securely communicating this information, and subsequently reconstructing the image. As an alternative, here we show how the image itself can be directly transmitted while ensuring that the presence of any cavesdropper is revealed in a way akin to quantum key distribution. We achieve this transmission using a photon-pair source with the deliberate addition of a thermal light source as background noise. One photon of the pair illuminates the object, which is masked from an eavesdropper by adding indistinguishable thermal photons, the other photon of the pair acts as a time reference from which the intended recipient can preferentially detect the image carrying photons. These reference photons are themselves made sensitive to the presence of an eavesdropper by traditional polarisation-based QKD encoding. Interestingly the security encoding is performed in the two-dimensional polarisation-basis, but the image information is encoded in a much higher-dimensional, hence information-rich, pixel basis. In our example implementation, our images have more than 100 independent pixels. Beyond the secure transmission of images, our approach to the distribution of secure high-dimensional information may create new high-bandwidth approaches to traditional QKD

    Creative Images: The Story of Savior in the Hidden Images of Biblical Events

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    Archived website and summary of exhibit in the Marian Library Artist: Ned Ostendorf Exhibit dates: May 7 - June 23, 201

    JPEG steganography with particle swarm optimization accelerated by AVX

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    Digital steganography aims at hiding secret messages in digital data transmitted over insecure channels. The JPEG format is prevalent in digital communication, and images are often used as cover objects in digital steganography. Optimization methods can improve the properties of images with embedded secret but introduce additional computational complexity to their processing. AVX instructions available in modern CPUs are, in this work, used to accelerate data parallel operations that are part of image steganography with advanced optimizations.Web of Science328art. no. e544
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