Home – Home – Jornals – Avtometriya 2015 number 2

An algorithm for detecting quasiperiodic textures is proposed, which is based on specific features of two-dimensional spectra obtained by using the discrete Fourier transform. The power spectra of the fragments are analyzed independently of each other, which provides the computational effectiveness of the detection algorithm. Examples demonstrating the use of the detection algorithm in the problem of image segmentation into two texture classes (periodic and nonperiodic) are presented. It is shown that the algorithm stably operates with significant deformations in the lattice of periodic textures.

A new nonparametric statistical test for testing the hypothesis of homogeneity of three samples against an alternative hypothesis, which implies that random variables of one of these samples tend to be stochastically greater than random variables of each of the other two samples separately, is proposed. The known Whitney test is equivalent to a particular case of the new test. Application of these tests in a real difficult problem of detection of a specified extended object in a noisy image in a situation with possible appearance of another “interfering” object of a greater size is considered.

The Moivre–Laplace asymptotics is used to construct an interval estimate of the probability distribution function that is an interval with random boundaries, which covers the true value of the distribution function with a given confidence factor. It is shown that the use of the asymptotic instead of a binomial probability distribution results in an error whose value is tolerable for small sampling sizes and monotonically reduces with decreases sampling size.

An approach to automatic determination of operation parameters of a hierarchical 3D recursive search (3DRS) algorithm is proposed and tested. A comparative study of the computational speed and noise immunity of the 3DRS algorithm used for constructing displacement vector fields, including the use of the Gaussian pyramids (hierarchical search), is performed. It is shown that application of the hierarchical 3DRS algorithm with operation parameters determined in this work can substantially increase its noise immunity and reduce the computational cost.

A criterion and an algorithm of detecting dynamic objects (DOs) in a complex background formed by an intense cumulus and high-altitude cumulus are proposed. The object image has a small size (point image) and low contrast. The principle of DO detection is fractal-correlation: it is based on the use of sampling as a relationship of likelihood functions of similar alternative conditions: either “only complex background within the sight of an optoelectron device (OED)” or “DO on the complex background within the sight of an OED.” The DO detection algorithm is designed as a binary accumulator according to the most powerful local criterion. The critical limit of decision making is defined by the Neumann - Pearson lemma for the acceptable possibility of false detection of a DO. Simulation proves the algorithm to be highly effective.

Results of a computational experiment, the choice of initial data, and the algorithm of calculating the range of operation of thermal imaging systems are considered for the case of object observation with different parameters of the object-background environment and detector elements. The results of the computational experiment are compared to actual investigations performed with an IRIS-AWS imager.

The method of dependence identification is described, in which each model is compared to a linear or nonlinear structural difference scheme. Inclusion of nonlinear difference schemes into structural models significantly expands the number of identifiable dependences. This method makes it possible to choose the sought model among the given set of dependences. The model chosen is a model for which the distance between the vector of estimates of autoregression coefficient and the corresponding tolerance range of coefficients of the structural difference scheme is minimum. This method was validated via statistical modeling by the Monte Carlo method.

A planar package of waveguides with heterogeneously implanted impurity resonance atoms is considered. The conditions of formation of dissipative solitons due to a competition of Kerr saturating nonlinearity and diffraction in the waveguide traps formed by impurity media are determined. It is shown that applying a constant electric field to an impurity resonance medium with a constant dipole moment makes it possible to control the propagation of solitons in Y-shaped waveguide traps.

A method of calculating the dynamics of alkali metal atoms interacting with resonance radiation in vacuum cells with a high-quality antirelaxation coating is proposed. The high quality of the coating means that the atom retains its spin after more than 1000 collisions with the wall.

In this paper, we propose a method for optimizing geometric objects such as polygons and triangulated piecewise planar surfaces, for the purposes of greater detailing and providing visual smoothness of their images. The initial object is treated as a geometric realization of a simplicial scheme. The method involves refining the simplicial scheme and biharmonic interpolation of the embedding function of a subdivision of the simplicial scheme in Euclidean space.

This paper studies polynomial multiwavelets of odd order having a support width equal to two grid spacings and orthogonal to polynomials of the same order on a finite interval. A new approach to calculating a multiwavelet transform is proposed based on an algorithm for solving systems of linear algebraic equations with a block-tridiagonal matrix using the matrix sweep method (block Gauss method). The results of numerical experiments for wavelets of fifth order are presented.

A solution to the problem of reliable discrimination between the move and stop states of a mine lift is proposed based on processing signals of an accelerometer mounted in the lift cabin. The accelerometer signal is processed using a combination of adaptive whitening algorithms and a nonparametric Neyman-Pearson test that provides an effective solution of the problem under a priori nonparametric uncertainty conditions.

The problem of contactless control of an unmanned aerial vehicle by human gestures is considered. A system of commands is proposed for an AR.Drone 2.0 quadcopter equipped with a builtin computer, two color video cameras, the Linux operating system, and sensors for measuring the flight height, speed, and stability. An Asus Xtion Pro Live three-dimensional sensor based on triangulation and structured light is used to enter data into the control system. Gesture recognition is performed by frame-by-frame processing of a video sequence consisting of depth images. The method does not require initial training, is insensitive to changes in lighting, and is invariant to the sizes of the human palm and body.

This paper presents the physical and technical principles of readout integrated circuit (ROIC) for reading and preprocessing focal plane array signals in the infrared spectral range 8–14 μm. The noise equivalent temperature difference of long-wavelength infrared focal plane arrays based on ROIC with frame integration of signals of multilayer quantum well structures is evaluated. The influence of technological limitations in silicon readout circuits for photo signals on the performance of IR focal plane arrays is analyze for a wide range of parameters of QWIP–based focal plane arrays and CMOS technology design rules.

An analytical model of a traveling-wave optical resonator with total-internal-reflection mirrors is studied. It is shown that the number of reflections from the mirrors can be increased manifold without attenuation of the light wave in comparison with Fabry-Perot resonators. Ways to eliminate edge effects and design solutions to compensate angular errors in manufacturing the resonator are considered.