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IEEE TRANSACTIONS ON COMPUTATIONAL IMAGING 2025年 11卷 170-178页

作者： Liu, Zicheng Qin, Yingying Tinguely, Jean-Claude Agarwal, Krishna Northwestern Polytech Univ Sch Elect & Informat Dept Elect Engn Xian 710029 Peoples R China UiT Arctic Univ Norway Dept Phys & Technol N-9037 Tromso Norway

point spread function (PSF) is quite important in modern computational microscopy techniques. Various approaches for measuring and modeling point spread functions have been proposed for both fluorescence and label-free microscopes. Among the various PSF candidates, it is often difficult to evaluate which PSF best suits the microscope and the experimental conditions. Visual qualification is often applied because there are hardly any techniques to quantify the quality of PSF as a basis for comparing different candidates and selecting the best one. To address this gap, we present a validation scheme based on the concept of confidence interval to evaluate the quality of fit of the PSF. This scheme is rigorous and supports precise validation for any microscope's PSF irrespective of their complexity, improving the performance of computational nanoscopy on them. We first demonstrate proof-of-principle of our scheme for a complex but practical label-free coherent imaging setup by comparing a variety of scalar and dyadic PSFs. Next, we validate our approach on conventional scalar PSFs using fluorescence based single molecule localization microscopy which needs PSF to compute the locations of single molecules. Lastly, we demonstrate how the scheme can be used in practice for challenging scenarios using images of gold nanorods placed on and illuminated by a photonic chip waveguide imaged using a label-free dark-field microscopy setup. Through these experiments, we demonstrate the generality and versatility of our PSF validation approach for the microscopy domain.

关键词： Microscopy Noise Fitting Optical microscopy Data models Computational modeling Analytical models Fluorescence Accuracy Photonics point spread functions validation of point spread functions dyadic Green's function Airy disk background noise photon counting error percentage of pixels in confidence interval (PPCI)

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point spread functions of photons in time-resolved transillumination experiments using simple scaling arguments

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MEDICAL PHYSICS 1996年第11期23卷 1857-1861页

作者： Chernomordik, V Nossal, R Gandjbakhche, AH Division of Computer Research and Technology Physical Sciences Laboratory National Institutes of Health Bethesda Maryland 20892

Simple scaling arguments are used to determine spatial resolution achievable in time-resolved transillumination experiments involving highly diffuse media. These arguments allow us to obtain relationships linking target resolution at different planes inside an optically turbid slab to the gating times of the imaging system. We show that this approach yields the same results as those obtained previously from an approximate and rather complicated analytical derivation. In addition, we are now able to assess the effects of scattering anisotropy on spatial resolution attainable when gating times are so short that a constant scaling of photon transport scattering length is not appropriate. These results should enable one to devise more accurate and simpler image reconstruction algorithms.

关键词： Thermography Image reconstruction tomography IMAGE FORMING IMAGE ANALYSIS VISIBLE RADIATION NEAR INFRARED RADIATION NEOPLASMS point spread functions TIME RESOLUTION SCALING 87.56.09 Spatial resolution Transillumination Photon scattering Photons Image reconstruction Anisotropy

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point spread functions with extended depth of focus

Point spread functions with extended depth of focus

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Conference on 3-Dimensional and Multidimensional Microscopy: Image Acquisition and Processing IX

作者： Wilson, T Neil, MAA Massoumian, F Univ Oxford Dept Engn Sci Oxford OX1 3PJ England

ISBN: (纸本)0819443603

The use of an annular pupil plane filter may be used to increase the depth of focus of an objective lens without significant deterioration of the lateral resolution. However this approach is very inefficient since most of the illumination light is blocked by the annular filter. We describe a method which uses a diffractive optical element to increase significantly the depth of focus but with dramatically increased light efficiency.

关键词： Axicons point spread functions Optical components Binary data Optical filters Objectives Beam shaping Diffractive optical elements Image filtering Roads

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Universal dictionaries for representation of turbulent atmosphere point spread functions

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OPTICAL ENGINEERING 2023年第1期62卷

作者： Hunt, Bobby R. Iler, Amber L. Sheppard, David G. KBR Inc Kihei HI USA KBR Inc Ann Arbor MI 48108 USA

Dictionary methods have proved very useful in compressive sensing. Herein we show that, for dictionaries to represent the point spread functions (PSFs) of image formation in atmospheric turbulence, it is possible to construct dictionaries computationally. Computationally created dictionaries make unnecessary the exhaustive collection of PSF data, for arbitrarily large numbers of conditions of turbulence and optical image formation systems, while also reducing the overall number of dictionaries that need to be created and stored. (c) The Authors. Published by SPIE under a Creative Commons Attribution 4.0 International License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

关键词： turbulence atmospheric optics point spread functions compressive sensing

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Scalability conjecture for the Fried parameter in synthesis of turbulent atmosphere point spread functions

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JOURNAL OF APPLIED REMOTE SENSING 2018年第4期12卷

作者： Hunt, Bobby R. Iler, Amber L. Rucci, Michael A. Integr Applicat Inc Pacific Def Solut Kihei HI 96753 USA Integr Applicat Inc Ann Arbor MI 48108 USA US Air Force Res Lab Wright Patterson AFB OH 45433 USA

A common method for synthesizing turbulent imagery is to model phase perturbations on a wavefront and then propagate the wavefront to the entrance pupil of an imaging system. The point spread function (PSF) that results from the wavefront in the pupil is then computed and used to synthesize images by the usual means of convolution. In a recent publication, a method was disclosed using sparse and redundant dictionaries of turbulent characteristics to construct PSFs directly in the image plane and simulate image formation without making phase models and computing wavefront propagation. However, the dictionary method, as disclosed in the recent publication, is limited to modeling PSFs characterized by the Fried parameter of the data used to construct the dictionary. Herein, we demonstrate that a dictionary constructed from data with a given Fried parameter can be scaled to construct turbulent PSFs corresponding to larger and smaller values of the Fried parameter. This enables a single dictionary, or a small number of dictionaries, to serve for the simulation of turbulent images over a range of turbulence conditions. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License.

关键词： image modeling and simulation turbulence sparse and redundant representations point spread functions atmospheric optics remote sensing image restoration

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Correcting Optical Aberration via Depth-Aware point spread functions

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IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE 2024年第8期46卷 5541-5555页

作者： Luo, Jun Nie, Yunfeng Ren, Wenqi Cao, Xiaochun Yang, Ming-Hsuan Chinese Acad Sci Inst Informat Engn Beijing 100093 Peoples R China Univ Chinese Acad Sci Sch Cyber Secur Beijing 100049 Peoples R China Yunnan Normal Univ Key Lab Educ Informatizat Nationalities Minist Educ Kunming 650500 Yunnan Peoples R China Vrije Univ Brussel Dept Appl Phys & Photon B-1050 Brussels Belgium Flanders Make B-1050 Brussels Belgium Sun Yat Sen Univ Sch Cyber Sci & Technol Shenzhen Campus Shenzhen 518107 Peoples R China Yunnan Key Lab Smart Educ Shenzhen 518107 Peoples R China Univ Calif Merced Merced CA 95343 USA

Optical aberration is a ubiquitous degeneration in realistic lens-based imaging systems. Optical aberrations are caused by the differences in the optical path length when light travels through different regions of the camera lens with different incident angles. The blur and chromatic aberrations manifest significant discrepancies when the optical system changes. This work designs a transferable and effective image simulation system of simple lenses via multi-wavelength, depth-aware, spatially-variant four-dimensional point spread functions (4D-PSFs) estimation by changing a small amount of lens-dependent parameters. The image simulation system can alleviate the overhead of dataset collecting and exploiting the principle of computational imaging for effective optical aberration correction. With the guidance of domain knowledge about the image formation model provided by the 4D-PSFs, we establish a multi-scale optical aberration correction network for degraded image reconstruction, which consists of a scene depth estimation branch and an image restoration branch. Specifically, we propose to predict adaptive filters with the depth-aware PSFs and carry out dynamic convolutions, which facilitate the model's generalization in various scenes. We also employ convolution and self-attention mechanisms for global and local feature extraction and realize a spatially-variant restoration. The multi-scale feature extraction complements the features across different scales and provides fine details and contextual features. Extensive experiments demonstrate that our proposed algorithm performs favorably against state-of-the-art restoration methods.

关键词： Optical imaging Adaptive optics Optical filters Lenses Image restoration Optical diffraction Feature extraction point spread functions optical aberration correction scene depth estimation image simulation

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Synthesis of atmospheric turbulence point spread functions by sparse and redundant representations

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OPTICAL ENGINEERING 2018年第2期57卷

作者： Hunt, Bobby R. Iler, Amber L. Bailey, Christopher A. Rucci, Michael A. Integr Applicat Inc Pacific Def Solut Kihei HI 96753 USA Integr Applicat Inc Ann Arbor MI 48108 USA Leidos Beavercreek OH USA Air Force Res Lab Wright Patterson AFB OH USA

Atmospheric turbulence is a fundamental problem in imaging through long slant ranges, horizontal-range paths, or uplooking astronomical cases through the atmosphere. An essential characterization of atmospheric turbulence is the point spread function (PSF). Turbulence images can be simulated to study basic questions, such as image quality and image restoration, by synthesizing PSFs of desired properties. In this paper, we report on a method to synthesize PSFs of atmospheric turbulence. The method uses recent developments in sparse and redundant representations. From a training set of measured atmospheric PSFs, we construct a dictionary of "basis functions" that characterize the atmospheric turbulence PSFs. A PSF can be synthesized from this dictionary by a properly weighted combination of dictionary elements. We disclose an algorithm to synthesize PSFs from the dictionary. The algorithm can synthesize PSFs in three orders of magnitude less computing time than conventional wave optics propagation methods. The resulting PSFs are also shown to be statistically representative of the turbulence conditions that were used to construct the dictionary. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License.

关键词： image modeling and simulation turbulence sparse and redundant representations point spread functions remote sensing image restoration

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A Quantitative Study of the Quality of Deconvolved Wide-field Microscopy Images as Function of Empirical Three-dimensional point spread functions

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JOURNAL OF THE OPTICAL SOCIETY OF KOREA 2011年第3期15卷 252-263页

作者： Adur, Javier Vicente, Nathalie Diaz-Zamboni, Javier Fernanda Izaguirre, Maria Hugo Casco, Victor Natl Univ Entre Rios Microscopy Lab Appl Mol & Cellular Studies Sch Engn RA-3100 Parana Argentina

In this work, for the first time, the quality of restoration in wide-field microscopy images after deconvolution was analyzed as a function of different point spread functions using one deconvolution method, on a specimen of known size and on a biological specimen. The empirical point spread Function determination can significantly depend on the numerical aperture, refractive index of the embedding medium, refractive index of the immersion oil and cover slip thickness. The influence of all of these factors is shown in the same article and using the same microscope. We have found that the best deconvolution results are obtained when the empirical PSF utilized is obtained under the same conditions as the specimen. We also demonstrated that it is very important to quantitatively check the process' outcome using several quality indicators: Full-Width at Half-Maximum, Contrast-to-Noise Ratio, Signal-to-Noise Ratio and a Tenengrad-based function. We detected a significant improvement when using an indicator to measure the focus of the whole stack. Therefore, to qualitatively determinate the best deconvolved image between different conditions, one approach that we are pursuing is to use Tenengrad-based function indicators in images obtained using a wide-field microscope.

关键词： Deconvolution point spread functions Image quality Optical sectioning

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Millimeter wave imaging with engineered point spread functions

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OPTICAL ENGINEERING 2012年第9期51卷

作者： Mait, Joseph N. Martin, Richard D. Schuetz, Christopher A. Prather, Dennis W. USA Res Lab Adelphi MD 20783 USA Phase Sensit Innovat Newark DE 19711 USA Univ Delaware Dept Elect & Comp Engn Newark DE 19716 USA

We demonstrate experimentally the ability to shape the point spread function of a distributed-aperture millimeter-wave imaging system by modifying its aperture phase. We consider distributions on a regular hexagonal array and a nonredundant array. We also show how to exploit this capability to perform low-resolution analog image processing. A preliminary investigation of system performance reveals nonuniformity in amplitude response across the array is a major contributor to deviations from predicted point spread functions (PSFs). (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/***.51.9.091606]

关键词： imaging systems phase-only filters point spread functions millimeter waves

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CALCULATION AND APPLICATION OF point spread functions FOR TREATMENT PLANNING WITH HIGH-ENERGY PHOTON BEAMS

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ACTA ONCOLOGICA 1987年第1期26卷 49-56页

作者： AHNESJO, A ANDREO, P BRAHME, A UPPSALA DATACENT DIV MED COMP PHYS S-75002 UPPSALA SWEDEN UNIV SARAGOSSA HOSP CLIN SECC FIS DEPT RADIOL SARAGOSSA SPAIN KAROLINSKA INST DEPT RADIAT PHYS S-10401 STOCKHOLM 60 SWEDEN UNIV STOCKHOLM S-10405 STOCKHOLM SWEDEN

A general dose calculation method for treatment planning with high energy photon beams, based on folding of the total energy released by primary photons per unit mass, the terma, with a fractional mean energy imparted point spread function is described. A set of point spread functions has been calculated with Monte Carlo technique for energies of primary photons between 100 keV and 20 MeV. Dose distributions have been calculated for a 6 MV beam using the method. The results clearly point out the considerably increased precision and flexibility achieved when calculating photon beam dose distributions from first principles using Monte Carlo generated point spread functions. The point spread functions calculated in this work are available on magnetic tape from the authors.

关键词： Dosimetry High energy photons point spread functions Treatment planning

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