Pub Date : 2022-10-01DOI: 10.18287/2412-6179-co-1174
S. Kharitonov, N. L. Kazanskiy, S. G. Volotovsky, S. Khonina
The work is devoted to the development of the quantum theory of diffractive optical elements. Aspects of quantum optics are considered by the example of light diffraction from a dielectric plate in a resonator. The paper shows the connection between the classical and quantum solution of the problem of diffraction by a dielectric plate. Expressions are obtained for the eigenmodes of such a resonator, as well as for the operators of the vector magnetic potential and the electric field strength. The method proposed in this paper can be easily extended to dielectric plates with a diffractive microrelief, that is, to diffractive optical elements.
{"title":"Calculation of quantum characteristics based on the classical solution of the diffraction problem in a resonator with a dielectric plate","authors":"S. Kharitonov, N. L. Kazanskiy, S. G. Volotovsky, S. Khonina","doi":"10.18287/2412-6179-co-1174","DOIUrl":"https://doi.org/10.18287/2412-6179-co-1174","url":null,"abstract":"The work is devoted to the development of the quantum theory of diffractive optical elements. Aspects of quantum optics are considered by the example of light diffraction from a dielectric plate in a resonator. The paper shows the connection between the classical and quantum solution of the problem of diffraction by a dielectric plate. Expressions are obtained for the eigenmodes of such a resonator, as well as for the operators of the vector magnetic potential and the electric field strength. The method proposed in this paper can be easily extended to dielectric plates with a diffractive microrelief, that is, to diffractive optical elements.","PeriodicalId":46692,"journal":{"name":"Computer Optics","volume":"93 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82718279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-01DOI: 10.18287/2412-6179-co-1105
S. V. Tsaplin, I. Belokonov, S. A. Bolychev, A. Romanov
We propose combining the functionality of star sensors and the optical system of a nanosatel-lite optical-electronic telescopic module (OETM) for Earth remote sensing (ERS) in order to re-duce the influence of thermoregulation inaccuracy on the accuracy of linking the star sky and the Earth's surface images. The main difference from the previous works is that for the thermoregula-tion inaccuracy to be reduced, we use controlled local film electric heaters with moderate energy consumption located on the periphery of optical elements of the OETM system. High quality of the star sky images is sought to be attained for a nanosatellite-borne telescope in a circular sun-synchronous orbit (SSO) and includes solving a number of tasks discussed below. Arguments are given in favor of using the proposed OETM, which is capable of fully complementing / replacing the onboard astronomical imaging system of spacecraft.
{"title":"Investigation of the operating conditions influence on the optical telescope performance when capturing star images","authors":"S. V. Tsaplin, I. Belokonov, S. A. Bolychev, A. Romanov","doi":"10.18287/2412-6179-co-1105","DOIUrl":"https://doi.org/10.18287/2412-6179-co-1105","url":null,"abstract":"We propose combining the functionality of star sensors and the optical system of a nanosatel-lite optical-electronic telescopic module (OETM) for Earth remote sensing (ERS) in order to re-duce the influence of thermoregulation inaccuracy on the accuracy of linking the star sky and the Earth's surface images. The main difference from the previous works is that for the thermoregula-tion inaccuracy to be reduced, we use controlled local film electric heaters with moderate energy consumption located on the periphery of optical elements of the OETM system. High quality of the star sky images is sought to be attained for a nanosatellite-borne telescope in a circular sun-synchronous orbit (SSO) and includes solving a number of tasks discussed below. Arguments are given in favor of using the proposed OETM, which is capable of fully complementing / replacing the onboard astronomical imaging system of spacecraft.","PeriodicalId":46692,"journal":{"name":"Computer Optics","volume":"26 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81710689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-01DOI: 10.18287/2412-6179-co-1081
N. Vasilyuk
A method for calculating of a blur kernel arising from the rotation of a digital camera is proposed. The rotation is measured with a three-axis gyroscope attached to the camera. Differential equations of a continuous trajectory of the rotational blur starting from a selected pixel are obtained. These equations are presented both in the form of an explicit system of differential equations for the blur curve in the focal plane and in the form of a matrix equation for the increment of the camera attitude. An expression is given for the integral of the energy illumination from a point light source along the continuous blur trajectory. The integral takes into account the point spread function and the aperture functions of individual photosensitive cells of the photodetector array. The calculation of the integral values for all photosensitive cells illuminated with the point source gives a discrete kernel of rotational blur starting at the selected pixel. Algorithms for the numerical integration of the blur equations are described. The analysis of the blur equations are carried out, characteristic features of the kernels are highlighted and their non-homogeneity is shown, with the kernels of rotational blur revealed not to coincide with each other for different pixels. An example of the synthesis of the blur kernels for given rotation parameters of the digital camera is given.
{"title":"Synthesis of the rotational blur kernel in a digital image using measurements of a triaxial gyroscope","authors":"N. Vasilyuk","doi":"10.18287/2412-6179-co-1081","DOIUrl":"https://doi.org/10.18287/2412-6179-co-1081","url":null,"abstract":"A method for calculating of a blur kernel arising from the rotation of a digital camera is proposed. The rotation is measured with a three-axis gyroscope attached to the camera. Differential equations of a continuous trajectory of the rotational blur starting from a selected pixel are obtained. These equations are presented both in the form of an explicit system of differential equations for the blur curve in the focal plane and in the form of a matrix equation for the increment of the camera attitude. An expression is given for the integral of the energy illumination from a point light source along the continuous blur trajectory. The integral takes into account the point spread function and the aperture functions of individual photosensitive cells of the photodetector array. The calculation of the integral values for all photosensitive cells illuminated with the point source gives a discrete kernel of rotational blur starting at the selected pixel. Algorithms for the numerical integration of the blur equations are described. The analysis of the blur equations are carried out, characteristic features of the kernels are highlighted and their non-homogeneity is shown, with the kernels of rotational blur revealed not to coincide with each other for different pixels. An example of the synthesis of the blur kernels for given rotation parameters of the digital camera is given.","PeriodicalId":46692,"journal":{"name":"Computer Optics","volume":"98 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79267009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-01DOI: 10.18287/2412-6179-co-1076
O. Nikolaeva
A multistep algorithm to detect cloudy objects in multispectral images is presented. Clustering spatial pixels by the k-means method and applying spectral criteria of cloudy/clear sky to fragments of obtained clusters are carried out in each step of the algorithm. One cloudy object is found in one step. Results of testing the algorithm on images from a sensor HYPERION (199 non-zero spectral bands in a 425 nm – 2400 nm interval under high spatial resolution of 30 m) are given. Images with discontinuous cloud cover above different surfaces (ocean, vegetation, desert, town, snow) are considered. An alternative method, in which the same spectral criteria are applied to each pixel, is also used in testing. Cloud masks obtained by both algorithms are compared. Mean spectra of obtained cloudy objects are given. The presented algorithm finds 1-3 cloudy objects corresponding to the brightness distribution in RGB images. Using the alternative algorithm (without preliminary clustering) leads to detection errors on the cloud edges. Three quality parameters are offered. The ratio of dispersion of "cloudy" spectra to dispersion of "clear" spectra is found to be most informative. This ratio should be much less than 1 when using a good cloudy mask.
{"title":"Technique of detecting cloudy objects in multispectral images","authors":"O. Nikolaeva","doi":"10.18287/2412-6179-co-1076","DOIUrl":"https://doi.org/10.18287/2412-6179-co-1076","url":null,"abstract":"A multistep algorithm to detect cloudy objects in multispectral images is presented. Clustering spatial pixels by the k-means method and applying spectral criteria of cloudy/clear sky to fragments of obtained clusters are carried out in each step of the algorithm. One cloudy object is found in one step. Results of testing the algorithm on images from a sensor HYPERION (199 non-zero spectral bands in a 425 nm – 2400 nm interval under high spatial resolution of 30 m) are given. Images with discontinuous cloud cover above different surfaces (ocean, vegetation, desert, town, snow) are considered. An alternative method, in which the same spectral criteria are applied to each pixel, is also used in testing. Cloud masks obtained by both algorithms are compared. Mean spectra of obtained cloudy objects are given. The presented algorithm finds 1-3 cloudy objects corresponding to the brightness distribution in RGB images. Using the alternative algorithm (without preliminary clustering) leads to detection errors on the cloud edges. Three quality parameters are offered. The ratio of dispersion of \"cloudy\" spectra to dispersion of \"clear\" spectra is found to be most informative. This ratio should be much less than 1 when using a good cloudy mask.","PeriodicalId":46692,"journal":{"name":"Computer Optics","volume":"49 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72512763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-01DOI: 10.18287/2412-6179-co-1121
C. Alexeyev, S. Aliyeva, E. Barshak, B. Lapin, M.A. Yavorsrky
In this paper, we studied transformations of structured light and its angular momentum in a three-coil optical snake – a coil resonator composed of 3 evanescently uniformly coupled coils of a multimode fiber. We have suggested a fully vectorial theory of normal modes of the 3-coil resona-tor, which takes account of the spin-orbit interaction. On the basis of the analytical expressions for such normal modes and their propagation constants we have studied transmission of some types of structured light beams – optical vortices, Hermite-Gaussian-like and Laguerre-Gaussian beams – through such a system. We have shown the possibility of a super-efficient parametric control over the topological charge, orbital and spin angular momenta of the outcoming optical field by this system. We have theoretically demonstrated implementation of logic X and Y Pauli gates for light beams carrying orbital angular momentum on the basis of such a 3-coil resonator.
{"title":"Structured light transformations and orbital angular momentum control in a three-coil optical snake","authors":"C. Alexeyev, S. Aliyeva, E. Barshak, B. Lapin, M.A. Yavorsrky","doi":"10.18287/2412-6179-co-1121","DOIUrl":"https://doi.org/10.18287/2412-6179-co-1121","url":null,"abstract":"In this paper, we studied transformations of structured light and its angular momentum in a three-coil optical snake – a coil resonator composed of 3 evanescently uniformly coupled coils of a multimode fiber. We have suggested a fully vectorial theory of normal modes of the 3-coil resona-tor, which takes account of the spin-orbit interaction. On the basis of the analytical expressions for such normal modes and their propagation constants we have studied transmission of some types of structured light beams – optical vortices, Hermite-Gaussian-like and Laguerre-Gaussian beams – through such a system. We have shown the possibility of a super-efficient parametric control over the topological charge, orbital and spin angular momenta of the outcoming optical field by this system. We have theoretically demonstrated implementation of logic X and Y Pauli gates for light beams carrying orbital angular momentum on the basis of such a 3-coil resonator.","PeriodicalId":46692,"journal":{"name":"Computer Optics","volume":"27 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89258080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-01DOI: 10.18287/2412-6179-co-1129
N. Ilyasova, D. Kirsh, N. Demin
In this work, we propose a decision-making support system for automatically mapping an effective photocoagulation pattern for the laser treatment of diabetic retinopathy. The purpose of research to create automated personalization of diabetic macular edema laser treatment. The results are based on analysis of large semi-structured data, methods and algorithms for fundus image processing. The technology improves the quality of retina laser coagulation in the treatment of diabetic macular edema, which is one of the main reasons for pronounced vision decrease. The proposed technology includes original solutions to establish an optimal localization of multitude burns by determining zones exposed to laser. It also includes the recognition of large amount of unstructured data on the anatomical and pathological locations' structures in the area of edema and data optical coherent tomography. As a result, a uniform laser application on the pigment epithelium of the affected retina is ensured. It will increase the treatment safety and its effectiveness, thus avoiding the use of more expensive treatment methods. Assessment of retinal lesions volume and quality will allow predicting the laser photocoagulation results and will contribute to the improvement of laser surgeon's skills. The architecture of a software complex comprises a number of modules, including image processing methods, algorithms for photocoagulation pattern mapping, and intelligent analysis methods.
{"title":"Decision-making support system for the personalization of retinal laser treatment in diabetic retinopathy","authors":"N. Ilyasova, D. Kirsh, N. Demin","doi":"10.18287/2412-6179-co-1129","DOIUrl":"https://doi.org/10.18287/2412-6179-co-1129","url":null,"abstract":"In this work, we propose a decision-making support system for automatically mapping an effective photocoagulation pattern for the laser treatment of diabetic retinopathy. The purpose of research to create automated personalization of diabetic macular edema laser treatment. The results are based on analysis of large semi-structured data, methods and algorithms for fundus image processing. The technology improves the quality of retina laser coagulation in the treatment of diabetic macular edema, which is one of the main reasons for pronounced vision decrease. The proposed technology includes original solutions to establish an optimal localization of multitude burns by determining zones exposed to laser. It also includes the recognition of large amount of unstructured data on the anatomical and pathological locations' structures in the area of edema and data optical coherent tomography. As a result, a uniform laser application on the pigment epithelium of the affected retina is ensured. It will increase the treatment safety and its effectiveness, thus avoiding the use of more expensive treatment methods. Assessment of retinal lesions volume and quality will allow predicting the laser photocoagulation results and will contribute to the improvement of laser surgeon's skills. The architecture of a software complex comprises a number of modules, including image processing methods, algorithms for photocoagulation pattern mapping, and intelligent analysis methods.","PeriodicalId":46692,"journal":{"name":"Computer Optics","volume":"26 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83976339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-01DOI: 10.18287/2412-6179-co-1089
J. Gulomov, R. Aliev, I. Gulomova
One of important tasks of the day is increasing the efficiency and decreasing the cost of the silicon solar cells. There is method of introducing of metal nanoparticles into solar cells to improve its absorption and reduce transmission as well as reflection coefficients. When metal nanoparticles are introduced into silicon solar cell, nanoplasmonic effect will occur. Nanoplasmonic effect lead to modification of light spectrum and generation of extra hot electrons. Nano-plasmonic effect strongly depends on size of nanoparticles. Therefore, in this paper, effect of gold nanoparticles size on properties of silicon solar cell has been studied by using simulation. Gold nanoparticles with sizes of 4 nm, 6 nm, 9 nm, 11 nm and 21 nm have been input into emitter region of silicon solar cell in order to use both of nanoplasmonic-electric and nanoplasmonic-optic effects for enhancing efficiency of silicon solar cell. Open circuit voltage didn't change when size of nanoparticles has been changed from 4 nm to 11 nm. It dropped by 0.017 V when size of nanoparticles was 21 nm. Short circuit current has been maximum 6.7 mA/cm2 at nanoparticle size of 11 nm and minimum 3.1 mA/cm2 at nanoparticle size of 21 nm. It has been found from obtained results that gold nanoparticle with size of 11 nm affected significantly on properties of silicon solar cell. Besides, thickness of silicon solar cell can be decreased without dropping of efficiency by introducing gold nanoparticles. Because, main part of photons is absorbed near to metal nanoparticles inputted region.
{"title":"Size effect of gold nanoparticles on optical and electrical properties of plasmonic silicon solar cell","authors":"J. Gulomov, R. Aliev, I. Gulomova","doi":"10.18287/2412-6179-co-1089","DOIUrl":"https://doi.org/10.18287/2412-6179-co-1089","url":null,"abstract":"One of important tasks of the day is increasing the efficiency and decreasing the cost of the silicon solar cells. There is method of introducing of metal nanoparticles into solar cells to improve its absorption and reduce transmission as well as reflection coefficients. When metal nanoparticles are introduced into silicon solar cell, nanoplasmonic effect will occur. Nanoplasmonic effect lead to modification of light spectrum and generation of extra hot electrons. Nano-plasmonic effect strongly depends on size of nanoparticles. Therefore, in this paper, effect of gold nanoparticles size on properties of silicon solar cell has been studied by using simulation. Gold nanoparticles with sizes of 4 nm, 6 nm, 9 nm, 11 nm and 21 nm have been input into emitter region of silicon solar cell in order to use both of nanoplasmonic-electric and nanoplasmonic-optic effects for enhancing efficiency of silicon solar cell. Open circuit voltage didn't change when size of nanoparticles has been changed from 4 nm to 11 nm. It dropped by 0.017 V when size of nanoparticles was 21 nm. Short circuit current has been maximum 6.7 mA/cm2 at nanoparticle size of 11 nm and minimum 3.1 mA/cm2 at nanoparticle size of 21 nm. It has been found from obtained results that gold nanoparticle with size of 11 nm affected significantly on properties of silicon solar cell. Besides, thickness of silicon solar cell can be decreased without dropping of efficiency by introducing gold nanoparticles. Because, main part of photons is absorbed near to metal nanoparticles inputted region.","PeriodicalId":46692,"journal":{"name":"Computer Optics","volume":"9 3 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87082029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-01DOI: 10.18287/2412-6179-co-1109
M. V. Savelyev, A. D. Remzov
A theoretical analysis of the dynamics of the spatial spectrum of the object wave in a degenerate four-wave mixing in a transparent solution of nanoparticles in the classical scheme with counterpropagating pump waves is carried out. It is shown that when pump waves propagate orthogonally to the gravity force, a dip arises in the modulus of the spatial spectrum of the object wave, with its half-width nonmonotonically decreasing over time and increasing in the direction of gravity force with increasing radius of the nanoparticles. There is an optimal time over which the half-width of the dip in the direction of the gravity force reaches the lowest value. This time decreases monotonically with increasing nanoparticle radius, as well as with a decrease in the solution thickness.
{"title":"Spatial and temporal characteristics of a four-wave radiation converter with due regard for Earth's gravity field acting on nanoparticles dissolved in a transparent liquid","authors":"M. V. Savelyev, A. D. Remzov","doi":"10.18287/2412-6179-co-1109","DOIUrl":"https://doi.org/10.18287/2412-6179-co-1109","url":null,"abstract":"A theoretical analysis of the dynamics of the spatial spectrum of the object wave in a degenerate four-wave mixing in a transparent solution of nanoparticles in the classical scheme with counterpropagating pump waves is carried out. It is shown that when pump waves propagate orthogonally to the gravity force, a dip arises in the modulus of the spatial spectrum of the object wave, with its half-width nonmonotonically decreasing over time and increasing in the direction of gravity force with increasing radius of the nanoparticles. There is an optimal time over which the half-width of the dip in the direction of the gravity force reaches the lowest value. This time decreases monotonically with increasing nanoparticle radius, as well as with a decrease in the solution thickness.","PeriodicalId":46692,"journal":{"name":"Computer Optics","volume":"63 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86708968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-01DOI: 10.18287/2412-6179-co-1020
V. Arlazarov, E.I. Andreeva, K. Bulatov, D. Nikolaev, O. Petrova, B. I. Savelev, O. Slavin
This paper analyzes the problems of document image recognition and the existing solutions. Document recognition algorithms have been studied for quite a long time, but despite this, currently, the topic is relevant and research continues, as evidenced by a large number of associated publications and reviews. However, most of these works and reviews are devoted to individual recognition tasks. In this review, the entire set of methods, approaches, and algorithms necessary for document recognition is considered. A preliminary systematization allowed us to distinguish groups of methods for extracting information from documents of different types: single-page and multi-page, with text and handwritten contents, with a fixed template and flexible structure, and digitalized via different ways: scanning, photographing, video recording. Here, we consider methods of document recognition and analysis applied to a wide range of tasks: identification and verification of identity, due diligence, machine learning algorithms, questionnaires, and audits. The groups of methods necessary for the recognition of a single page image are examined: the classical computer vision algorithms, i.e., keypoints, local feature descriptors, Fast Hough Transforms, image binarization, and modern neural network models for document boundary detection, document classification, document structure analysis, i.e., text blocks and tables localization, extraction and recognition of the details, post-processing of recognition results. The review provides a description of publicly available experimental data packages for training and testing recognition algorithms. Methods for optimizing the performance of document image analysis and recognition methods are described.
{"title":"Document image analysis and recognition: a survey","authors":"V. Arlazarov, E.I. Andreeva, K. Bulatov, D. Nikolaev, O. Petrova, B. I. Savelev, O. Slavin","doi":"10.18287/2412-6179-co-1020","DOIUrl":"https://doi.org/10.18287/2412-6179-co-1020","url":null,"abstract":"This paper analyzes the problems of document image recognition and the existing solutions. Document recognition algorithms have been studied for quite a long time, but despite this, currently, the topic is relevant and research continues, as evidenced by a large number of associated publications and reviews. However, most of these works and reviews are devoted to individual recognition tasks. In this review, the entire set of methods, approaches, and algorithms necessary for document recognition is considered. A preliminary systematization allowed us to distinguish groups of methods for extracting information from documents of different types: single-page and multi-page, with text and handwritten contents, with a fixed template and flexible structure, and digitalized via different ways: scanning, photographing, video recording. Here, we consider methods of document recognition and analysis applied to a wide range of tasks: identification and verification of identity, due diligence, machine learning algorithms, questionnaires, and audits. The groups of methods necessary for the recognition of a single page image are examined: the classical computer vision algorithms, i.e., keypoints, local feature descriptors, Fast Hough Transforms, image binarization, and modern neural network models for document boundary detection, document classification, document structure analysis, i.e., text blocks and tables localization, extraction and recognition of the details, post-processing of recognition results. The review provides a description of publicly available experimental data packages for training and testing recognition algorithms. Methods for optimizing the performance of document image analysis and recognition methods are described.","PeriodicalId":46692,"journal":{"name":"Computer Optics","volume":"100 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79487781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-01DOI: 10.18287/2412-6179-co-1131
D. Savelyev
The focusing features of a super-Gaussian beam, as well as Laguerre-super-Gaussian (1,0) modes with radial and circular polarizations on ring gratings (direct and inverse) with a variable height of individual relief rings were investigated in this paper. The change in the height of the relief from the maximum height in the center to the minimum at the edges of the element (direct ring grating) is considered and the reverse case, when the maximum height of the relief was at the edges and the minimum in the center (reverse ring grating). The comparison was carried out with the action of a diffractive axicon with a comparable grating period. Numerical simulation was carried out by the finite differences in the time domain method. It was shown that the direction of change in the height of the relief rings of elements significantly affects the diffraction pattern in the near zone. In particular, for a super-Gaussian beam, the use of a direct ring grating made it possible to reduce the size of the focal spot by 18.7% for radial polarization ('sigma'=5 μm), the use of a reverse ring grating led to a decrease in the focal spot by 36.9% ('sigma'=12.25 µm) in comparison with the action of a diffractive axicon. It was also shown in the paper that when the reverse ring grating is illuminated by the Laguerre-superGauss (1,0) mode with circular polarization, the formation of a narrow and extended region of reduced intensity on the optical axis (optical trap) is observed.
{"title":"Peculiarities of focusing circularly and radially polarized super-Gaussian beams using ring gratings with varying relief height","authors":"D. Savelyev","doi":"10.18287/2412-6179-co-1131","DOIUrl":"https://doi.org/10.18287/2412-6179-co-1131","url":null,"abstract":"The focusing features of a super-Gaussian beam, as well as Laguerre-super-Gaussian (1,0) modes with radial and circular polarizations on ring gratings (direct and inverse) with a variable height of individual relief rings were investigated in this paper. The change in the height of the relief from the maximum height in the center to the minimum at the edges of the element (direct ring grating) is considered and the reverse case, when the maximum height of the relief was at the edges and the minimum in the center (reverse ring grating). The comparison was carried out with the action of a diffractive axicon with a comparable grating period. Numerical simulation was carried out by the finite differences in the time domain method. It was shown that the direction of change in the height of the relief rings of elements significantly affects the diffraction pattern in the near zone. In particular, for a super-Gaussian beam, the use of a direct ring grating made it possible to reduce the size of the focal spot by 18.7% for radial polarization ('sigma'=5 μm), the use of a reverse ring grating led to a decrease in the focal spot by 36.9% ('sigma'=12.25 µm) in comparison with the action of a diffractive axicon. It was also shown in the paper that when the reverse ring grating is illuminated by the Laguerre-superGauss (1,0) mode with circular polarization, the formation of a narrow and extended region of reduced intensity on the optical axis (optical trap) is observed.","PeriodicalId":46692,"journal":{"name":"Computer Optics","volume":"29 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83882962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：