scholarly journals Reconstruction of 3D Temperature Profile of Radiative Participatory Flame Based on Digital Refocusing Technique of Light Field Camera

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Biao Zhang ◽  
Chen Wang ◽  
Yudong Liu ◽  
Chuanlong Xu ◽  
Qi Qi
Keyword(s):  
Temperature Profile ◽  
Light Field ◽  
Imaging System ◽  
Flame Temperature ◽  
Reconstruction Accuracy ◽  
Camera System ◽  
Pollutant Formation ◽  
Imaging Model ◽  
Spread Function ◽  
Candle Flame

Accurate and reliable measurements of the 3D flame temperature profile are highly desirable to achieve in-depth understanding of the combustion and pollutant formation processes. In this paper, a measurement method for reconstruction of a 3D flame temperature profile was proposed by using a light field camera. It combines the convolution imaging model and radiative transfer equation and takes into account the characteristics of emission, absorption, and scattering of a semitransparent flame. According to the point spread function characteristics of the imaging system, the number and positions of the refocus planes were set by comprehensive consideration of the reconstruction accuracy and efficiency. The feasibility of the present method was proved by numerical simulation and an experiment of a candle flame. This method achieves the reconstruction of a 3D asymmetric flame profile through a single exposure of a single camera, which overcomes the problem of complexity of a multicamera system and the time delay of a conventional scanning camera system.

Near-infrared fundus imaging system with light illumination from an electronic contact lens

2022 ◽  
Vol 15 (2) ◽  
pp. 027001
Author(s):  
Yang Cui ◽  
Taiki Takamatsu ◽  
Koichi Shimizu ◽  
Takeo Miyake
Keyword(s):  
Contact Lens ◽  
Near Infrared ◽  
Imaging System ◽  
Low Cost ◽  
Light Illumination ◽  
Fundus Images ◽  
Fundus Imaging ◽  
Point Spread ◽  
Spread Function ◽  
Dependent Point

Abstract As for the diagnosis and treatment of eye diseases, an ideal fundus imaging system is expected to be portability, low cost, and high resolution. Here, we demonstrate a non-mydriatic near-infrared fundus imaging system with light illumination from an electronic contact lens (E-lens). The E-lens can illuminate the retinal and choroidal structures for capturing the fundus images when voltage is applied wirelessly to the lens. And we also reconstruct the images with a depth-dependent point-spread function to suppress the scattering effect that eventually visualizes the clear fundus images.

Measurement of the Point Spread Function of a Photoacoustic Imaging System using Step Method

2013 ◽  
Vol 33 (4) ◽  
pp. 0411002
Author(s):  
周红仙 Zhou Hongxian ◽  
周有平 Zhou Youping ◽  
王毅 Wang Yi
Keyword(s):  
Point Spread Function ◽  
Imaging System ◽  
Photoacoustic Imaging ◽  
Step Method ◽  
Point Spread ◽  
Spread Function

Point Spread Function Model of Grating Imaging System Based on Boltzmann Function Edge Fitting

2020 ◽  
Vol 40 (14) ◽  
pp. 1405003
Author(s):  
卢泉 Lu Quan ◽  
张泽昊 Zhang Zehao ◽  
张卫平 Zhang Weiping ◽  
刘诣荣 Liu Yirong
Keyword(s):  
Point Spread Function ◽  
Imaging System ◽  
Function Model ◽  
Point Spread ◽  
Boltzmann Function ◽  
Spread Function

Survey on Imaging Model and Calibration of Light Field Camera

2016 ◽  
Vol 43 (6) ◽  
pp. 0609004
Author(s):  
张春萍 Zhang Chunping ◽  
王庆 Wang Qing
Keyword(s):  
Light Field ◽  
Imaging Model

Point Spread Function of Pinhole Imaging System for Deviating from Center of Incident γ-Ray

2015 ◽  
Vol 44 (3) ◽  
pp. 311004
Author(s):  
马庆力 MA Qing-li ◽  
唐世彪 TANG Shi-biao ◽  
吴彦华 WU Yan-hua
Keyword(s):  
Point Spread Function ◽  
Imaging System ◽  
Point Spread ◽  
Spread Function ◽  
Pinhole Imaging ◽  
Γ Ray

Development of Near-Diffraction Limited, Low-Cost and High-Resolution CCD Camera System for Imaging Coulter Orifices

2014 ◽  
Vol 4 (2) ◽  
pp. 54-61
Author(s):  
Sami D. Alaruri
Keyword(s):  
Imaging System ◽  
Low Cost ◽  
Ccd Camera ◽  
Image Plane ◽  
Geometric Optic ◽  
Optical Path Difference ◽  
Path Difference ◽  
Modulation Transfer ◽  
Camera System ◽  
Micro Lens

A low-cost CCD camera system for imaging Coulter orifices ranging in diameter between 20 µm and 2 mm has been developed and tested. The imaging system incorporates a 6X magnifying lens for viewing the required range of Coulter orifices and LEDs (Light emitting diodes) lamp for back illuminating the orifices. Geometric optic calculations using Zemax® for the micro-lens interfaced with the camera suggest that the spot diameter and the MTF spatial frequency at field of view equal to 0 ° and at the image plane are 5.13 µm and 271.6 lines/mm (at contrast= 37.6%), respectively. Images captured with the camera system for 20 µm, 100 µm and 2 mm diameter orifices are provided. Furthermore, a discussion for the camera micro-lens modulation transfer function, spot diagram, root-mean-square wavefront error versus field and optical path difference plots is given.

Theoretical Assessment of Convective and Radiative Heat Losses in a One-Dimensional Multiregion Premixed Flame With Counter-Flow Design Crossing Through Biofuel Particles

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Mehdi Bidabadi ◽  
Saman Hosseinzadeh ◽  
Sadegh Sadeghi ◽  
Mostafa Setareh
Keyword(s):  
Temperature Profile ◽  
Radiative Heat ◽  
Flame Structure ◽  
Flame Temperature ◽  
Heat Losses ◽  
Flame Velocity ◽  
Mass Fractions ◽  
Interface Matching ◽  
Energy Balances ◽  
Stagnation Plane

Due to perspective of biomass usage as a viable source of energy, this paper suggests a potential theoretical approach for studying multiregion nonadiabatic premixed flames with counterflow design crossing through the mixture of air (oxidizer) and lycopodium particles (biofuel). In this research, convective and radiative heat losses are analytically described. Due to the properties of lycopodium, roles of drying and vaporization are included so that the flame structure is created from preheating, drying, vaporization, reaction, and postflame regions. To follow temperature profile and mass fraction of the biofuel in solid and gaseous phases, dimensionalized and nondimensionalized forms of mass and energy balances are expressed. To ensure the continuity and calculate the positions of drying, vaporization, and flame fronts, interface matching conditions are derived employing matlab and mathematica software. For validation purpose, results for temperature profile is compared with those provided in a previous research study and an appropriate is observed under the same conditions. Finally, changes in flame velocity, flame temperature, solid and gaseous fuel mass fractions, and particle size with position measured from the position of stagnation plane, strain rate, and heat transfer coefficient in the presence/absence of losses are evaluated.

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