Computer Optics

941-946

Authors: Tukmakov K.N., Komlenok M.S., Pavelyev V.S., Kononenko T.V., Konov V.I.

A method of high-frequency laser ablation using a two-coordinate beam scanner for the fabrication of a diffractive element of terahertz range with a continuous profile has been developed and successfully applied. Results of the characterization of the fabricated microrelief of a silicon focuser of a Gaussian beam into a square region are presented.

959-969

Authors: Dyachenko A.A., Maksimova L.A., Ryabukho V.P.

An effect of the angular spectrum width of a polychromatic illuminating field on the interference pattern color in optical microscopy of stratified objects is considered. Equations describing the intensity of interference patterns of thin stratified objects are obtained with due account for the influence of both frequency and angular spectra of the illuminating field. The angular spectrum width of the illuminating field is shown to affect the mutual coherence and phase difference of the interfering fields. Computer-simulated interference patterns for a thin layer under monochromatic and polychromatic illumination with different widths of the angular spectrum are presented. Quantitative analysis of the effect of angular aperture of white light on the colors of the resulting interference pattern is carried out. Changes in the colors of the layer interference patterns are experimentally studied when changing the width of the angular spectrum of the illuminating field. Color variations of the interference patterns obtained experimentally and theoretically are compared.

977-984

Authors: Kozlova E.S.

Using a FDTD-method implemented in the FullWAVE (RSoft) software, a process of generating optical vortices during the propagation of a left- or right-hand circularly polarized Gaussian pulse through a phase and amplitude spiral zone plate with topological charge 2, a diameter of 8 μm, and a focal length of 532 nm is numerically modeled. An investigation of the amplitude and phase distributions in the focal plane shows the presence of optical vortices with topological charge 2. Analysis of the longitudinal component of the Umov-Poynting vector shows the presence of an inverse energy flow in the focal plane. In the case of using an amplitude spiral zone plate, the magnitude of the reverse flow decreases sharply until it disappears completely for the left circularly polarized incident beams.

998-1007

Authors: Myasnikov V.V.

An approach to constructing a description of data and images based on the search for an optimal configuration (permutation) of their components (pixels, regions, feature vectors, etc.) is proposed. The quality criterion of the configuration, which may be selected in accordance with the application, determines the concept of optimal configuration. With specific configurations, the whole set of analyzed data / images is broken down into equivalent subclasses characterized by identical descriptors. Issues of invariant description, robustness of the proposed presentation, and the relationship of the proposed approach with the existing ones (Local Binary Patterns (LBP) and image representation by sign data) are considered. By way of illustration, an applied problem is solved using the proposed approach.

1015-1021

Authors: Krevetsky A.V., Chesnokov S.E.

Questions of recognizing images of multiple objects whose dimensions are close to the resolution limit of recording equipment - groups of point objects (GPO) - are investigated. Images in the form of GPOs are found in radar images, whereas images of large-scale objects represented by characteristic points, clusters of data in a feature space, and events in mass service systems and automated control systems can be reduced to them. GPO recognition is complicated by disconnectedness of constituent elements, the narrowness of the image utocorrelation function in terms of the geometric transform parameters, spatial fluctuations of elements, false markings and omissions of signal markings. The most promising approaches to the image recognition of this type are based on the transformation of the GPO into a connected object - an associated continuous image (ACI) - and the analysis of its secondary features. However, for GPO with a non-stationary configuration and / or partially masked GPO, the recognition issues are still poorly investigated. The paper proposes an approach to the recognition of GPO based on the marking of their elements - the identification of point objects to within a metaclass (family, type) that is stable for nonstationary and partially masked GPOs. Four metaclasses are proposed: the extreme and inner points of the GPO with a chain structure, the outer and inner points of clusters. The essence of the approach to marking point marks is the recognition of complex-valued contour codes composed of samples of the cylindrical sections of an associated continuous image (ASI) around the GPO elements. To form the ASI, a vector field with partial sources in the elements of the GPO is used. Evaluations of the reliability of marking under various observation conditions are obtained. The results of marking are both of independent significance for various applied problems and suited for the subsequent recognition of GPO. Approaches to GPO recognition based on the results of marking of their elements are suggested.

1035-1045

Authors: Boori M.S., Paringer R., Choudhary K., Kupriyanov A.

The main aim of this research work is to compare k-nearest neighbor algorithm (KNN) supervised classification with migrating means clustering unsupervised classification (MMC) method on the performance of hyperspectral and multispectral data for spectral land cover classes and develop their spectral library in Samara, Russia. Accuracy assessment of the derived thematic maps was based on the analysis of the classification confusion matrix statistics computed for each classified map, using for consistency the same set of validation points. We were analyzed and compared Earth Observing-1 (EO-1) Hyperion hyperspectral data to Landsat 8 Operational Land Imager (OLI) and Advance Land Imager (ALI) multispectral data. Hyperspectral imagers, currently available on airborne platforms, provide increased spectral resolution over existing space based sensors that can document detailed information on the distribution of land cover classes, sometimes species level. Results indicate that KNN (95, 94, 88 overall accuracy and .91, .89, .85 kappa coefficient for Hyp, ALI, OLI respectively) shows better results than unsupervised classification (93, 90, 84 overall accuracy and .89, .87, .81 kappa coefficient for Hyp, ALI, OLI respectively). Development of spectral library for land cover classes is a key component needed to facilitate advance analytical techniques to monitor land cover changes. Different land cover classes in Samara were sampled to create a common spectral library for mapping landscape from remotely sensed data. The development of these libraries provides a physical basis for interpretation that is less subject to conditions of specific data sets, to facilitate a global approach to the application of hyperspectral imagers to mapping landscape. In addition, it is demonstrated that the hyperspectral satellite image provides more accurate classification results than those extracted from the multispectral satellite image. The higher classification accuracy by KNN supervised was attributed principally to the ability of this classifier to identify optimal separating classes with low generalization error, thus producing the best possible classes’ separation.

1054-1061

Authors: Vasin N.N., Diyazitdinov R.R.

In this article, we describe algorithms for superposition of a profile of the rail under measurement and that of an unused rail. The algorithms calculate parameters of the superposition, which links the two profiles, with one of them being described by a set of points and the other - by line equations. The algorithms are intended for evaluating the rail wear based on the data from triangulation scanners, which are installed on a track measuring car.

1068-1073

Authors: Chernov V.M.

The paper considers nonstandard binary number systems for rings of Gauss and Eisenstein integers. The principal difference ("exoticism") of such number systems from the canonical number systems introduced by I. Katai for quadratic fields is that as a binary "digital alphabet", it uses a two-element set that does not contain a numeric zero. The paper also synthesizes algorithms for the representation of numbers in the considered number system and characterizes the possibility of an efficient implementation of arithmetic operations.

1083-1092

Authors: Kochegurova E.A., Wu D.

In this paper the possibility of development of the recursive digital filter using a P-spline is considered. The frequency and time response of the spline filter for real-time data are analytically obtained and investigated. The influence of the P-spline parameters on effectiveness of interpretation is explored with input metrical data. The patterns obtained during spline filter frequency analysis are confirmed by an example of Doppler function restoration.

1101-1111

Authors: Agafonov A.A., Yumaganov A.S., Myasnikov V.V.

Accurate and timely information on the current and predicted traffic flows is important for the successful deployment of intelligent transport systems. These data play an essential role in traffic management and control. Using traffic flow information, travelers could plan their routes to avoid traffic congestion, reduce travel time and environmental pollution, as well as improving traffic operation efficiency in general. In this paper, we propose a distributed model for short-term traffic flow prediction based on a k nearest neighbors method, that takes into account spatial and temporal traffic flow distributions. The proposed model is implemented as a MapReduce based algorithm in an Apache Spark framework. An experimental study of the proposed model is carried out on a traffic flow data in the transportation network of Samara, Russia. The results demonstrate that the proposed model has high predictive accuracy and an execution time sufficient for real-time prediction.