检索结果-内蒙古大学图书馆

4th Conference on Novel Optical Systems Design and Optimization

作者： Mezouari, S Harvey, AR Heriot Watt Univ Dept Comp & Elect Engn Edinburgh EH14 4AS Midlothian Scotland

ISBN: (纸本)0819441562

As improving manufacturing techniques drive down the expense of imaging detector arrays, the total costs of future thermal imaging systems will become increasingly dominated by the manufacturing costs of the complex lens systems that are necessary for athermalization and achromatization. The concept of wavefront encoding combined with post-detection digital decoding has previously been shown to produce systems that are insensitive to thermal and chromatic defocus in slow imaging systems. In this paper we describe the application of the wavefront coding technique to thermal imaging systems with particular emphasis on the specific difficulties encountered. These difficulties include the use and effects of fast optics (similar tof/1), wide fields of view and noise amplification in low-contrast thermal images. Modeling results will be presented using diffraction models. We will describe the optimization of the wavefront encoding technique with a specific aim to reduce weight, size, and cost whilst maintaining acceptable imaging performance.

关键词： IR imaging athermalization image gathering wavefront coding thermal imaging defocus aberration

来源：评论

学校读者我要写书评

暂无评论

Effect of point spread function position bias in wavefront coding infrared imaging system

引用

JOURNAL OF OPTICS 2020年第2期22卷 025703-025703页

作者： Feng, Bin Shi, Zelin Liu, Haizheng Zhao, Yaohong Zhang, Jianlei Chinese Acad Sci Key Lab Optoelect Informat Proc Shenyang 110016 Peoples R China Chinese Acad Sci Shenyang Inst Automat Shenyang 110016 Peoples R China Northwestern Polytech Univ Sch Automat Xian 710072 Peoples R China Xian Univ Post & Telecommun Coll Elect Engn Xian 710121 Peoples R China

By an experimental finding, for a given radiant point source and a given infrared detector sampling, an optical point spread function (PSF) falling on different positions of an infrared detector focal plane array, will result in different measured PSFs. Those measured PSFs known as decoding kernels will further produce different decoded images. Therefore, this work explores the effect of PSF position bias on decoded images in a wavefront coding infrared imaging system. This paper theoretically analyzes the effect of PSF position bias on decoded images. A simulation is conducted for qualitatively evaluating the effect of PSF position bias on decoded images by mean structural similarity (MSSIM) index. Simulated results prove that the probability for MSSIM index greater than 0.75 is 91.38%, and that for less than 0.5 is only 1.22% but this minority seriously degrades the decoded images. We construct an experimental setup for capturing the raw PSF image at a random position and proposes a procedure to reduce the noise of a raw PSF image. The experimental result demonstrates the feasibility for measuring a PSF to achieve a decoded image with good quality.

关键词： wavefront coding infrared imaging PSF position bias decoded image

来源：评论

学校读者我要写书评

暂无评论

Use of a spatial light modulator as an adaptable phase mask for wavefront coding

引用

JOURNAL OF MODERN OPTICS 2010年第10期57卷 893-900页

作者： Carles, G. Muyo, G. Bosch, S. Harvey, A. R. Univ Barcelona Dept Fis Aplicada & Opt E-08028 Barcelona Spain Heriot Watt Univ Sch Engn & Phys Sci Edinburgh EH14 4AS Midlothian Scotland

A wavefront-coded imaging system employing a spatial light modulator (SLM) for the agile implementation of phase masks is presented. The SLM is a liquid crystal display that can be modulated to implement cubic phase masks of variable coding strength. These phase masks produce broad point spread functions insensitive to defocus aberration and are used in combination with post-detection digital image processing to extend the depth-of-field of an imaging system. A detailed description of the calibration process of the SLM in phase mode is presented together with experimental results which include wavefront-coded modulation transfer functions and increased depth-of-field images. The most interesting feature is the versatility provided by the imaging system, as compared to conventional (fixed phase mask) designs, and the agility in which it is done.

关键词： wavefront coding phase mask spatial light modulator imaging systems image processing

来源：评论

学校读者我要写书评

暂无评论

Alleviating image artifacts in wavefront coding extended depth of field imaging system

引用

OPTICS COMMUNICATIONS 2019年 436卷 232-238页

作者： Mo, Xutao Zhang, Tao Wang, Bin Huang, Xianshan Kuang, Cuifang Liu, Xu Anhui Univ Technol Sch Math & Phys Maanshan 243002 Peoples R China Zhejiang Univ State Key Lab Modern Opt Instrumentat Coll Opt Sci & Engn Hangzhou 310027 Zhejiang Peoples R China Shanxi Univ Collaborat Innovat Ctr Extreme Opt Taiyuan 030006 Shanxi Peoples R China

Optical imaging systems with extended depth of field based on wavefront coding can be used in many fields, which require more object information along the optical axis in a snapshot. When using the non-rotational symmetric phase masks such as cubic phase mask, the final images are usually restored by classical wiener restoration method. However, the existence of image artifacts in final restored images is a problem to be solved. We proposed a method to alleviate the image artifacts by processing two conjugate images, which are captured by image sensor before and after rotating the phase mask 180 degrees along the optical axis. Unlike the previous methods usually need to measure the point spread function or optical transfer function of the imaging system, we do not need to measure them anymore. Both the ZEMAX simulation and experiment verified our method.

关键词： Computational imaging wavefront coding Extended depth of field

来源：评论

学校读者我要写书评

暂无评论

Phase mask selection in wavefront coding systems: A design approach

引用

OPTICS AND LASERS IN ENGINEERING 2010年第7-8期48卷 779-785页

作者： Carles, Guillem Carnicer, Artur Bosch, Salvador Univ Barcelona Dept Fis Aplicada & Opt E-08028 Barcelona Spain

A method for optimizing the strength of a parametric phase mask for a wavefront coding imaging system is presented. The method is based on an optimization process that minimizes a proposed merit function. The goal is to achieve modulation transfer function invariance while quantitatively maintaining final image fidelity. A parametric filter that copes with the noise present in the captured images is used to obtain the final images, and this filter is optimized. The whole process results in optimum phase mask strength and optimal parameters for the restoration filter. The results for a particular optical system are presented and tested experimentally in the laboratory. The experimental results show good agreement with the simulations, indicating that the procedure is useful. (C) 2010 Elsevier Ltd. All rights reserved.

关键词： Imaging systems Image processing wavefront coding Phase mask optimization

来源：评论

学校读者我要写书评

暂无评论

Integrative optimization of the practical wavefront coding systems for depth-of-field extension

引用

OPTIK 2017年 144卷 621-627页

作者： Lu, Yu Zhao, Tingyu Zhang, Xingxu Qiu, Rongsheng Liu, Aiping Chen, Ruipin Yu, Feihong Zhejiang Sci Tech Univ Sci Coll Dept Phys 928 2nd St Hangzhou 310018 Zhejiang Peoples R China Shanghai Aerosp Control Technol Inst 1555 ZhongChun Rd Shanghai 201109 Peoples R China Zhejiang Univ Dept Opt Engn 38 Zheda Rd Hangzhou 310013 Zhejiang Peoples R China

Optimization of the phase mask is one of the key tasks in the design of wavefront coding systems for depth of field extension. Instead of optimization of the phase mask for ideal optical systems, which was the focus of the previous research, this paper proposes an integrative optimization method for practical optical systems considering the various optical aberrations. A practical wavefront coding system based on a doublet is designed using the integrative optimization method, while an ideal system with an optimized phase mask is also used for comparison. The simulation results show that the practical wavefront coding system designed by the integrative optimization method works well on both the on-axis and off-axis fields, while the ideal system with the optimized phase mask had a poor performance on the off-axis fields. Off-axis fields should also be considered as well as on-axis field in the design of practical optical systems, therefore the integrative optimization method will be significant for the design of practical wavefront coding systems. (C) 2017 Elsevier GmbH. All rights reserved.

关键词： wavefront coding Integrative optimization Practical optical system Fisher information

来源：评论

学校读者我要写书评

暂无评论

Learning wavefront coding for Extended Depth of Field Imaging

引用

IEEE TRANSACTIONS ON IMAGE PROCESSING 2021年 30卷 3307-3320页

作者： Akpinar, Ugur Sahin, Erdem Meem, Monjurul Menon, Rajesh Gotchev, Atanas Tampere Univ Fac Informat Technol & Commun Sci Tampere 33720 Finland Univ Utah Dept Elect & Comp Engn Salt Lake City UT 84102 USA

Depth of field is an important factor of imaging systems that highly affects the quality of the acquired spatial information. Extended depth of field (EDoF) imaging is a challenging ill-posed problem and has been extensively addressed in the literature. We propose a computational imaging approach for EDoF, where we employ wavefront coding via a diffractive optical element (DOE) and we achieve deblurring through a convolutional neural network. Thanks to the end-to-end differentiable modeling of optical image formation and computational post-processing, we jointly optimize the optical design, i.e., DOE, and the deblurring through standard gradient descent methods. Based on the properties of the underlying refractive lens and the desired EDoF range, we provide an analytical expression for the search space of the DOE, which is instrumental in the convergence of the end-to-end network. We achieve superior EDoF imaging performance compared to the state of the art, where we demonstrate results with minimal artifacts in various scenarios, including deep 3D scenes and broadband imaging.

关键词： Imaging Apertures Lenses Optics Image coding Optical refraction Optical imaging wavefront coding neural networks extended depth of field

来源：评论

学校读者我要写书评

暂无评论

Optimization of wavefront coding Phase Mask Applied to 5X-40X Micro-Objectives Simultaneously

引用

JOURNAL OF THE OPTICAL SOCIETY OF KOREA 2015年第5期19卷 487-493页

作者： Liu, Jiang Miao, Erlong Sui, Yongxin Yang, Jianghuai Chinese Acad Sci Changchun Inst Opt Fine Mech & Phys Engn Researcher Ctr Extreme Precis Opt Changchun 130033 Jilin Peoples R China Grad Univ Chinese Acad Sci Beijing 100049 Peoples R China

A wavefront coding (WFC) technique provides an extension of the depth of field for a microscopy imaging system with slight loss of image spatial resolution. Through the analysis of the relationship between the incidence angle of light at the phase mask and the system pupil function, a mixing symmetrical cubic phase mask (CPM) applied to 5X-40X micro-objectives is optimized simultaneously based on point-spread function (PSF) invariance and nonzero mean values of the modulation transfer function (MTF) near the spatial cut-off frequency. Optimization results of the CPM show that the depth of field of these micro-objectives is extended 3-10 times respectively while keeping their resolution. Further imaging simulations also prove its ability in enhancing the defocus imaging.

关键词： wavefront coding Micro-objective Depth of field Imaging system

来源：评论

学校读者我要写书评

暂无评论

Design and implementation of a scene-dependent dynamically selfadaptable wavefront coding imaging system

引用

COMPUTER PHYSICS COMMUNICATIONS 2012年第1期183卷 147-154页

作者： Carles, Guillem Ferran, Carme Carnicer, Artur Bosch, Salvador Univ Barcelona Dept Fis Aplicada & Opt E-08028 Barcelona Spain

A computational imaging system based on wavefront coding is presented. wavefront coding provides an extension of the depth-of-field at the expense of a slight reduction of image quality. This trade-off results from the amount of coding used. By using spatial light modulators, a flexible coding is achieved which permits it to be increased or decreased as needed. In this paper a computational method is proposed for evaluating the output of a wavefront coding imaging system equipped with a spatial light modulator, with the aim of thus making it possible to implement the most suitable coding strength for a given scene. This is achieved in an unsupervised manner, thus the whole system acts as a dynamically selfadaptable imaging system. The program presented here controls the spatial light modulator and the camera, and also processes the images in a synchronised way in order to implement the dynamic system in real time. A prototype of the system was implemented in the laboratory and illustrative examples of the performance are reported in this paper. Program summary Program title: DynWFC (Dynamic wavefront coding) Catalogue identifier: AEKC_v1_0 Program summary URL: http://***/summaries/AEKC_v1_*** Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://***/licence/*** No. of lines in distributed program, including test data, etc.: 10 483 No. of bytes in distributed program, including test data, etc.: 2 437 713 Distribution format: *** Programming language: Labview 8.5 and NI Vision and MinGW C Compiler Computer: Tested on PC Intel (R) Pentium (R) Operating system: Tested on Windows XP Classification: 18 Nature of problem: The program implements an enhanced wavefront coding imaging system able to adapt the degree of coding to the requirements of a specific scene. The program controls the acquisition by a camera, the display of a spatial light modulator

关键词： Imaging systems Image processing wavefront coding Selfadaptable coding strength

来源：评论

学校读者我要写书评

暂无评论

Design of an off-axis three-mirror anastigmatic optical system with wavefront coding technology

引用

OPTICAL ENGINEERING 2008年第6期47卷 063001-1-063001-1页

作者： Yan, Feng Chinese Acad Sci Changchun Inst Opt Fine Mech & Phys Opt Technol Res Ctr Changchun 130033 Peoples R China Chinese Acad Sci Grad Sch Beijing 100084 Peoples R China

wavefront coding (WFC) technology can extend the depth of focus of an optical system, which makes the application of this technology to space cameras extremely attractive. This paper introduces the application of wavefront coding to three-mirror anastigmatic optical systems. A transition model is established, in which the secondary mirror is regarded as the wavefront coding element and redesigned according to mathematical calculation. A comparison of modulation transfer function (MTF) behavior between the traditional system and the innovative system with wavefront coding technology is provided. The MTF behavior of both on-axis and off-axis field-of-view points remains the same in spite of the extended depth of focus. It is also observed that the system becomes very insensitive to aberration related to defocus through WFC technology. Errors in optical design and its improvement are discussed. The linear transition model is proven to be an acceptable one. Finally, an extension factor for the depth of focus is defined, and its effect is presented graphically. (C) 2008 Society of Photo-Optical Instrumentation Engineers.

关键词： wavefront coding secondary mirror depth of focus pupil function MTF PSF

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：