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V. N. Gorbachev

Publications and source records attributed to V. N. Gorbachev.

At least 19 recordsLinked to original sources
arXiv2019

On basis images for the digital image representation

Digital array orthogonal transformations that can be presented as a decomposition over basis items or basis images are considered. The orthogonal transform provides digital data scattering, a process of pixel energy redistributing, that is illustrated with the help of basis images. Data scattering plays important role for applications as image coding and watermarking. We established a simple quantum analogues of basis images. They are representations of quantum operators that describe transition of single particle between its states. Considering basis images as items of a matrix, we introduced a block matrix that is suitable for orthogonal transforms of multi-dimensional arrays such as block vector, components of which are matrices. We present an orthogonal transform that produces correlation between arrays. Due to correlation new feature of data scattering was found. A presented detection algorithm is an example of how it can be used in frequency domain watermarking.

cs.MM↗
arXiv2017

On the steganographic image based approach to PDF files protection

Digital images can be copied without authorization and have to be protected. Two schemes for watermarking images in PDF document were considered. Both schemes include a converter to extract images from PDF pages and return the protected images back. Frequency and spatial domain embedding were used for hiding a message presented by a binary pattern. We considered visible and invisible watermarking and found that spatial domain LSB technique can be more preferable than frequency embedding using DWT.

cs.MM↗
arXiv2015

The blind detection for palette image watermarking without changing the color

To hide a binary pattern in the palette image a steganographic scheme with blind detection is considered. The embedding algorithm uses the Lehmer code by palette color permutations for which the cover image palette is generally required. The found transformation between the palette and RGB images allows to extract the hidden data without any cover work.

cs.MM↗
arXiv2015

Embedding of binary image in the Gray planes

For watermarking of the digital grayscale image its Gray planes have been used. With the help of the introduced representation over Gray planes the LSB embedding method and detection have been discussed. It found that data, a binary image, hidden in the Gray planes is more robust to JPEG lossy compression than in the bit planes.

cs.MM↗
arXiv2014

Color to Gray and Back transformation for distributing color digital images

The Color to Gray and Back transformation watermarking with a secrete key is considered. Color is embedded into the bit planes of the luminosity component of the YUV color space with the help of a block algorithm that allows using not only the least significant bits. An application of the problem of distributing color digital images from a data base among legitimate users is discussed. The proposed protocol can protect original images from unauthorized copying.

cs.MM↗
arXiv2011

A binary noisy channel to model errors in printing process

To model printing noise a binary noisy channel and a set of controlled gates are introduced. The channel input is an image created by a halftoning algorithm and its output is the printed picture. Using this channel robustness to noise between halftoning algorithms can be studied. We introduced relative entropy to describe immunity of the algorithm to noise and tested several halftoning algorithms.

cs.OH↗
arXiv2006

Decay and storage of multiparticle entangled states of atoms in collective thermostat

We derive a master equation describing the collective decay of two-level atoms inside a single mode cavity in the dispersive limit. By considering atomic decay in the collective thermostat, we found a decoherence-free subspace of the multiparticle entangled states of the W-like class. We present a scheme for writing and storing these states in collective thermostat.

quant-ph↗
arXiv2006

Quantum channel for light based on integrals of motion

A method based on integrals of motion for collective processes has been introduced to achieve physical schemes in which one of the systems is insensitive to interaction. Decoherence-free quantum channels that allow sending any state of light, particulary the Fock states, through an absorbing medium are considered as an example.

quant-ph↗
arXiv2005

On Multiparticle Entanglement via Resonant Interaction between Light and atomic Ensembles

Multiparticle entangled states generated via interaction between narrow-band light and an ensemble of identical two-level atoms are considered. Depending on the initial photon statistics, correlation between atoms and photons can give rise to entangled states of these systems. It is found that the state of any pair of atoms interacting with weak single-mode squeezed light is inseparable and robust against decay. Optical schemes for preparing entangled states of atomic ensembles by projective measurement are described.

quant-ph↗
arXiv2004

On parametric type interaction between light and atomic ensembles

One-photon and Raman type interactions between two-level atoms and narrow-band light are considered. We give some exactly solvable models of these processes when only one-photon Fock states are involved in the evolution. Possible application of these models for generation and transformation of entangled states of the W-class, some of which demonstrate hierarchy structure, are discussed. Finally, we consider preparation of entangled chains of atomic ensembles.

quant-ph↗
arXiv2003

Can the states of the W-class be suitable for teleportation

Entangled states of the W-class are considered as a quantum channel for teleportation or the states to be sent. The protocols have been found by unitary transformation of the schemes, based on the multiuser GHZ channel. The main feature of the W-quantum channels is a set of non-local operators, that allow receivers recovering unknown state.

quant-ph↗
arXiv2003

On preparation of the W-states from atomic ensembles

A scheme, where three atomic ensembles can be prepared in the states of the W-class via Raman type interaction of strong classical field and a projection measurement involved three single-photon detectors and two beamsplitters, are considered. The obtained atomic entanglement consists of the Dicke or W-states of each of the ensembles.

quant-ph↗
arXiv2003

On amplification of light in the continuous EPR state

Two schemes of amplification of two-mode squeezed light in the continuous variable EPR-state are considered. They are based on the integrals of motion, which allow conserving quantum correlations whereas the power of each mode may increase. One of these schemes involves a three-photon parametric process in a nonlinear transparent medium and second is a Raman type interaction of light with atomic ensemble.

quant-ph↗
arXiv2002

Master Equation for Light emitted by correlated Atoms

A master equation for light generated by atoms, which states are prepared by a pumping mechanism that produces atomic correlations, is derived in the Fokker-Planck approximation. It has been found that two-particle correlations only play the role under this approach. Then the equation is applied for describing micromaser operations and light noise is discussed. We consider the correlated atomic states prepared by telecloning protocols.

quant-ph↗
arXiv2001

Teleportation of entangled states and dense coding using a multiparticle quantum channel

A set of protocols for teleportation and dense coding tasks with the use of a N particle quantum channel, presented by entangled states of the GHZ class, is introduced, when N>2. Using a found representation for the multiparticle entangled states of the GHZ class, it has shown, that for dense coding schemes enhancement of the classical capacity of the channel due from entanglement is N/N-1. If N>2 there is no one - to -one correspondence between teleportation and dense coding schemes in comparison with the EPR channel is exploited. A set of schemes, for which two additional operations as entanglement and disentanglement are permitted, is considered.

quant-ph↗
arXiv2000

Teleportation of entanglement for continuous variables

Teleportation of a pure two particle entangled state of continuous variables by triplet of the Greenberger-Horne-Zeilinger form is considered. The three-particle basis needed for a joint measurement is found. It describes a measurement of momentum one of single particle and total moment and relative position of the two others. Optical realization using squeezed state of the light is discussed.

quant-ph↗
arXiv1999

Transfer formalism for quantum optics problems

Consistent quantum formalism based on the localized basis of the Wannirer functions in Heisenberg and Schrodinger pictures to describe propagation of electromagnetic field in a three dimensional media including diffraction is presented. In the Schrodinger picture the Fokker-Planck equation for the Glauber-Sudarshan quasiprobability and corresponding Langevin equations are given. As result the space-time description is obtained by a simple changing variables in the temporal master equation of the field. Using this formalism it is shown that the existence of integrals of motion in the propagation of light in a medium under the condition of nondegenerated parametric and two-photon interactions results in amplification of modes when nonclassical properties of the light are conserved. Quantum propagation of light in a linear medium taking into account the diffraction is considered and its solution is found.

quant-ph↗