Calibration of a Microlens Array for a Plenoptic Camera

2014 ◽  
Author(s):  
Chelsea M. Thomason ◽  
Brian S. Thurow ◽  
Timothy W. Fahringer
Keyword(s):  
Microlens Array ◽  
Plenoptic Camera

Focused Plenoptic Camera and Spatial Resolution Improving Technology

2013 ◽  
Vol 710 ◽  
pp. 419-423
Author(s):  
Juan Ning Zhao ◽  
Xiao Na Dong ◽  
Suo Chao Yuan
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Traditional Approach ◽  
Microlens Array ◽  
Low Resolution ◽  
New Approach ◽  
Plenoptic Camera ◽  
High Resolution Images

The focused plenoptic cameras based on the rays resampling of microlens array on the image formed by main lens, captures radiation on sensor includes the 4D radiance information.Because of both spatial and angular information are recorded on the sensor of fixed pixels number, when rendering image with fixed view there are limited pixels from sub_image are adopted, this results in disappointingly low resolution of the result image. Our approach presents a new approach to rendering an image with higher spatial resolution than the traditional approach, allowing us to render high resolution images that meet the high requirements.

scholarly journals Depth-of-Field-Extended Plenoptic Camera Based on Tunable Multi-Focus Liquid-Crystal Microlens Array

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4142 ◽  
Author(s):  
Mingce Chen ◽  
Wenda He ◽  
Dong Wei ◽  
Chai Hu ◽  
Jiashuo Shi ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Radiation Power ◽  
Focal Length ◽  
Microlens Array ◽  
Oxide Semiconductor ◽  
Depth Of Field ◽  
Digital Refocusing ◽  
Wide Range ◽  
Cmos Sensor ◽  
Plenoptic Camera

Plenoptic cameras have received a wide range of research interest because it can record the 4D plenoptic function or radiance including the radiation power and ray direction. One of its important applications is digital refocusing, which can obtain 2D images focused at different depths. To achieve digital refocusing in a wide range, a large depth of field (DOF) is needed, but there are fundamental optical limitations to this. In this paper, we proposed a plenoptic camera with an extended DOF by integrating a main lens, a tunable multi-focus liquid-crystal microlens array (TMF-LCMLA), and a complementary metal oxide semiconductor (CMOS) sensor together. The TMF-LCMLA was fabricated by traditional photolithography and standard microelectronic techniques, and its optical characteristics including interference patterns, focal lengths, and point spread functions (PSFs) were experimentally analyzed. Experiments demonstrated that the proposed plenoptic camera has a wider range of digital refocusing compared to the plenoptic camera based on a conventional liquid-crystal microlens array (LCMLA) with only one corresponding focal length at a certain voltage, which is equivalent to the extension of DOF. In addition, it also has a 2D/3D switchable function, which is not available with conventional plenoptic cameras.

An electrically tunable plenoptic camera using a liquid crystal microlens array

2015 ◽  
Vol 86 (5) ◽  
pp. 053101 ◽  
Author(s):  
Yu Lei ◽  
Qing Tong ◽  
Xinyu Zhang ◽  
Hongshi Sang ◽  
An Ji ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Microlens Array ◽  
Plenoptic Camera

Local error and its identification for microlens array in plenoptic camera

2018 ◽  
Vol 108 ◽  
pp. 41-53 ◽  
Author(s):  
Su-Ning Li ◽  
Yuan Yuan ◽  
Bin Liu ◽  
Fu-Qiang Wang ◽  
He-Ping Tan
Keyword(s):  
Microlens Array ◽  
Local Error ◽  
Plenoptic Camera

scholarly journals Investigation of Best Practices in Volumetric Reconstruction for Plenoptic PIV

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Bibek Sapkota ◽  
Dustin Kelly ◽  
Zu Puayen Tan ◽  
Brian S. Thurow
Keyword(s):  
Best Practices ◽  
3D Reconstruction ◽  
Light Field ◽  
Incident Light ◽  
Microlens Array ◽  
Light Rays ◽  
Plenoptic Camera ◽  
Volumetric Reconstruction ◽  
Commercial Off The Shelf ◽  
Recorded Image

This paper investigates the effect of smoothing operation in 3D reconstruction using a plenoptic camera. A plenoptic camera - also known as light field camera - features a commercial off the shelf camera with added microlens array (MLA) behind the imaging lens, directly in front of the sensor. The main lens focuses the light to the MLA plane, where each microlens then re-directs the light to small regions of pixels behind, each pixel corresponding to different angle of incident (T. Fahringer (2015)) (Adelson and Wang (1992)). Thus, MLA encodes angular information of incident light rays into the recorded image that assist to acquire 4D information (u,v,s,t) of light-field including both position and angular information of light rays captured by the camera (Ng et al. (2005)) (Adelson and Wang (1992)).

Plenoptic camera based on a liquid crystal microlens array

2015 ◽  
Author(s):  
Yu Lei ◽  
Qing Tong ◽  
Xinyu Zhang ◽  
Hongshi Sang ◽  
Changsheng Xie
Keyword(s):  
Liquid Crystal ◽  
Microlens Array ◽  
Plenoptic Camera

scholarly journals Integrated Double-Sided Random Microlens Array Used for Laser Beam Homogenization

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 673
Author(s):  
Wei Yuan ◽  
Cheng Xu ◽  
Li Xue ◽  
Hui Pang ◽  
Axiu Cao ◽  
...  
Keyword(s):  
Laser Beam ◽  
Microlens Array ◽  
Energy Utilization ◽  
Utilization Rate ◽  
Periodic Lattice ◽  
Lattice Distribution ◽  
Speckle Field ◽  
High Laser ◽  
Alignment Problem ◽  
In Series

Double microlens arrays (MLAs) in series can be used to divide and superpose laser beam so as to achieve a homogenized spot. However, for laser beam homogenization with high coherence, the periodic lattice distribution in the homogenized spot will be generated due to the periodicity of the traditional MLA, which greatly reduces the uniformity of the homogenized spot. To solve this problem, a monolithic and highly integrated double-sided random microlens array (D-rMLA) is proposed for the purpose of achieving laser beam homogenization. The periodicity of the MLA is disturbed by the closely arranged microlens structures with random apertures. And the random speckle field is achieved to improve the uniformity of the homogenized spot by the superposition of the divided sub-beams. In addition, the double-sided exposure technique is proposed to prepare the rMLA on both sides of the same substrate with high precision alignment to form an integrated D-rMLA structure, which avoids the strict alignment problem in the installation process of traditional discrete MLAs. Then the laser beam homogenization experiments have been carried out by using the prepared D-rMLA structure. The laser beam homogenized spots of different wavelengths have been tested, including the wavelengths of 650 nm (R), 532 nm (G), and 405 nm (B). The experimental results show that the uniformity of the RGB homogenized spots is about 91%, 89%, and 90%. And the energy utilization rate is about 89%, 87%, 86%, respectively. Hence, the prepared structure has high laser beam homogenization ability and energy utilization rate, which is suitable for wide wavelength regime.

scholarly journals Research on surface quality difference of Microlens array fabricated by fast tool servo cutting

2021 ◽  
pp. 1-1
Author(s):  
Yuetian Huang ◽  
Shijie Li ◽  
Jin Zhang ◽  
Chen Yang ◽  
Yingxiu Kong ◽  
...  
Keyword(s):  
Surface Quality ◽  
Microlens Array ◽  
Fast Tool Servo ◽  
Quality Difference
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