scholarly journals Image processing algorithms for a light-field camera and their application for optical flow diagnostics

2016 ◽  
pp. 224-233
Author(s):  
А.В. Серёдкин ◽  
М.П. Токарев
Keyword(s):  
Spatial Resolution ◽  
Optical Sensors ◽  
Light Field ◽  
Three Dimensional ◽  
Fluid Flows ◽  
Computational Photography ◽  
Gas Flows ◽  
Experimental Fluid Mechanics ◽  
Measurement Area ◽  
Experimental Fluid

Применение современных оптико-электронных приборов расширяет возможности исследований в области экспериментальной механики жидкостей. Методы вычислительной фотографии за счет использования основанных на ней устройств постепенно проникают в различные области науки и техники. Камера светового поля может использоваться для регистрации трехмерных распределений скорости в потоках жидкости и газа там, где расположение нескольких панорамных оптических сенсоров затруднено за счет ограничения оптического доступа и вибраций. В работе исследованы возможности пленоптической системы, состоящей из доступной на рынке промышленной камеры светового поля применительно для диагностики течений жидкости и газа. Предложен и протестирован новый программный алгоритм для вычисления карты глубины регистрируемой измерительной области. Согласно полученным результатам, пространственное разрешение метода по глубине при использовании 11 мегапиксельного сенсора достигает 1/40 от глубины резкости оптической системы. Указанный метод был использован для измерения 3D-полей скорости турбулентной струи внутри щелевого канала по всей его глубине. В будущем количество задач, в которых целесообразно использование пленоптических устройств с высоким пространственным разрешением, будет расти. Application of modern optoelectronic devices extends research in the field of experimental fluid mechanics. The methods of computational photography gradually penetrate into the various fields of science and technology due to using devices based on these methods. A light-field camera can be used to register a three-dimensional velocity distribution in fluid flows where the location of several panoramic optical sensors is difficult because of restrictions in an optical access and vibrations. in this paper we study the possibility of using a plenoptic system consisting of an industrial light-field camera to diagnose liquid and gas flows. A new software algorithm for computing a depth field of a measurement area is proposed. According to the obtained results, the spatial resolution of the method by depth reaches 1/40th of the depth of the field of the optical system when using 11 MP sensor. This method was used to measure 3D velocity fields of a turbulent jet inside a slot channel throughout its depth. In the future, the number of applications will grow for the cases where the use of plenoptic devices with high spatial resolution is appropriate.

Experimental and Numerical Techniques in Fluids (Invited Lecture)

2005 ◽  
Author(s):  
Franz Durst
Keyword(s):  
Fluid Flow ◽  
Fluid Mechanics ◽  
18Th Century ◽  
Fluid Flows ◽  
Optical Methods ◽  
Experimental Fluid Mechanics ◽  
Flow Problems ◽  
Basic Equations ◽  
The University ◽  
Experimental Fluid

The development of fluid mechanics is briefly reviewed and the importance of fluid flows to heat and mass transport in nature as well as in science and engineering is outlined. The early theoretical developments are explained and it is indicated that the basic equations were already available at the end of the 18th century. Methods to solve these equations for engineering flows were not, however, developed until the second half of the 20th century. This was an important period for fluid flow research during which all the experimental fluid mechanics methods, particularly the optical methods, available today were also developed. The same is true for all the numerical methods that are used very successfully nowadays to solve scientific and engineering fluid flow problems. The Institute of Fluid Mechanics at the University of Erlangen-Nu¨rnberg has contributed extensively to these developments.

The development of a three—dimensional imaging system and its application in fluid mechanics

2001 ◽  
Vol 215 (12) ◽  
pp. 1459-1463 ◽  
Author(s):  
M T Stickland ◽  
S McKay ◽  
T J Scanlon
Keyword(s):  
Fluid Mechanics ◽  
Imaging System ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Three Dimensional Imaging ◽  
Experimental Fluid Mechanics ◽  
Air Bubble ◽  
Image Velocimetry ◽  
Selection Of ◽  
Experimental Fluid

This paper details the application of a three-dimensional imaging system known as planar contour imaging (PCI) to the presentation of experimental fluid mechanics data. The experimental datasets consisted of pseudo three-dimensional particle image velocimetry (PIV) vector maps of the flowfield around an air bubble growing at the base of a water column. The vectors from the experimental datasets were projected into three-dimensional space and the ease of their interpretation was assessed. It was found that the selection of the correct type and amount of data presented to the viewer was critical. However, when the image was refined, the three-dimensional image was found to produce an impressive representation of the flowfield contained within the experimental dataset.

scholarly journals Full-chain modeling and performance analysis of integral imaging three-dimensional display system

2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Ying Yuan ◽  
Xiaorui Wang ◽  
Yang Yang ◽  
Hang Yuan ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Optimization Design ◽  
Quality Evaluation ◽  
Light Field ◽  
Three Dimensional ◽  
Display System ◽  
3D Display ◽  
Performance Characterization ◽  
Integral Imaging ◽  
Characterization Model ◽  
Display Quality

Abstract The full-chain system performance characterization is very important for the optimization design of an integral imaging three-dimensional (3D) display system. In this paper, the acquisition and display processes of 3D scene will be treated as a complete light field information transmission process. The full-chain performance characterization model of an integral imaging 3D display system is established, which uses the 3D voxel, the image depth, and the field of view of the reconstructed images as the 3D display quality evaluation indicators. Unlike most of the previous research results using the ideal integral imaging model, the proposed full-chain performance characterization model considering the diffraction effect and optical aberration of the microlens array, the sampling effect of the detector, 3D image data scaling, and the human visual system, can accurately describe the actual 3D light field transmission and convergence characteristics. The relationships between key parameters of an integral imaging 3D display system and the 3D display quality evaluation indicators are analyzed and discussed by the simulation experiment. The results will be helpful for the optimization design of a high-quality integral imaging 3D display system.

Efficient chemosensors for toxic pollutants based on photoluminescent Zn(II) and Cd(II) metal-organic networks

2021 ◽  
Author(s):  
Luis David Rosales-Vazquez ◽  
Alejandro Dorazco-González ◽  
Victor Sanchez-Mendieta
Keyword(s):  
Optical Sensors ◽  
Three Dimensional ◽  
High Sensitivity ◽  
Environmental Research ◽  
Toxic Pollutants ◽  
Sensitivity And Selectivity ◽  
Metal Organic ◽  
Analytical Tools ◽  
Organic Networks

Optical sensors with high sensitivity and selectivity, as important analytical tools for chemical and environmental research, can be accomplished by straightforward synthesis of luminescent one-, two- and three-dimensional Zn(II) and...

Visualizing Fluid Flows With X-Rays

2007 ◽  
Author(s):  
Theodore J. Heindel ◽  
Terrence C. Jensen ◽  
Joseph N. Gray
Keyword(s):  
Computed Tomography ◽  
Flow Visualization ◽  
Three Dimensional ◽  
Fluid Flows ◽  
X Rays ◽  
Radiographic Images ◽  
Optical Access ◽  
X Ray ◽  
X Ray Computed ◽  
Density Map

There are several methods available to visualize fluid flows when one has optical access. However, when optical access is limited to near the boundaries or not available at all, alternative visualization methods are required. This paper will describe flow visualization using an X-ray system that is capable of digital X-ray radiography, digital X-ray stereography, and digital X-ray computed tomography (CT). The unique X-ray flow visualization facility will be briefly described, and then flow visualization of various systems will be shown. Radiographs provide a two-dimensional density map of a three dimensional process or object. Radiographic images of various multiphase flows will be presented. When two X-ray sources and detectors simultaneously acquire images of the same process or object from different orientations, stereographic imaging can be completed; this type of imaging will be demonstrated by trickling water through packed columns and by absorbing water in a porous medium. Finally, local time-averaged phase distributions can be determined from X-ray computed tomography (CT) imaging, and this will be shown by comparing CT images from two different gas-liquid sparged columns.

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