High resolution retinal imaging system based on semi-blind deconvolution restoration

2012 ◽  
Vol 20 (6) ◽  
pp. 1374-1381
Author(s):  
梁春 LIANG Chun ◽  
沈建新 SHEN Jian-xin ◽  
钮赛赛 NIU Sai-sai
Keyword(s):  
High Resolution ◽  
Blind Deconvolution ◽  
Imaging System ◽  
Retinal Imaging

scholarly journals Statistical analysis of ocular monochromatic aberrations in Chinese population for adaptive optics ophthalmoscope design

2017 ◽  
Vol 10 (01) ◽  
pp. 1650038 ◽  
Author(s):  
Junlei Zhao ◽  
Fei Xiao ◽  
Jian Kang ◽  
Haoxin Zhao ◽  
Yun Dai ◽  
...  
Keyword(s):  
High Resolution ◽  
Adaptive Optics ◽  
Chinese Population ◽  
Imaging System ◽  
Retinal Imaging ◽  
Clinical Environment ◽  
Monochromatic Aberrations ◽  
Imaging System Design ◽  
Healthy Eyes

It is necessary to know the distribution of the Chinese eye’s aberrations in clinical environment to guide high-resolution retinal imaging system design for large Chinese population application. We collected the monochromatic wave aberration of 332 healthy eyes and 344 diseased eyes in Chinese population across a 6.0-mm pupil. The aberration statistics of Chinese eyes including healthy eyes and diseased eyes were analyzed, and some differences of aberrations between the Chinese and European race were concluded. On this basis, the requirement for adaptive optics (AO) correction of the Chinese eye’s monochromatic aberrations was analyzed. The result showed that a stroke of 20[Formula: see text][Formula: see text]m and ability to correct aberrations up to the 8th Zernike order were needed for reflective wavefront correctors to achieve near diffraction-limited imaging in both groups for a reference wavelength of 550[Formula: see text]nm and a pupil diameter of 6.0[Formula: see text]mm. To verify the analysis mentioned above, an AO flood-illumination system was established, and high-resolution retinal imaging in vivo was achieved for Chinese eye including both healthy and diseased eyes.

High Resolution Retinal Imaging Based on Ocular Aberration Measurement and Compensation

2012 ◽  
Vol 246-247 ◽  
pp. 213-218
Author(s):  
Chun Liang ◽  
Jian Xin Shen ◽  
Sai Sai Niu
Keyword(s):  
High Resolution ◽  
Adaptive Optics ◽  
Imaging System ◽  
Low Cost ◽  
Critical Role ◽  
Retinal Imaging ◽  
Retinal Disease ◽  
Retinal Cell ◽  
Wavefront Aberration ◽  
Diagnostic Modality

Ocular retinal imaging is a major diagnostic modality for retinal disease, and can play a critical role for diagnosing systemic diseases such as diabetes and eye-specific diseases such as macular degeneration and diabetic retinopathy, the leading causes of blindness. In order to get high-resolution retinal imaging and develop the low-cost and compact retinal imaging system, we employ micro adaptive optics, which is consisted of wavefront sensor, wavefront corrector and control system. In this paper, the theory, design and testing of the ocular retinal microscopy is detailed, with an emphasis on the eye wavefront aberration describing, aberration detecting method with Hartmann-Shack wavefront sensing and close-loop aberration compensating by micromachined membrane deformable mirrors(MMDM).The ocular retinal microscopy experimental setup is built, the retinal cell imaging had been snapped. It is showed in this work that the ocular retinal microscopy based on adaptive optics system can enable diffraction-limited imaging of micro-scale features of the retina, through real-time compensation of aberrations introduced by the eye.

scholarly journals Iterative-Trained Semi-Blind Deconvolution Algorithm to Compensate Straylight in Retinal Images

2021 ◽  
Vol 7 (4) ◽  
pp. 73
Author(s):  
Francisco J. Ávila ◽  
Jorge Ares ◽  
María C. Marcellán ◽  
María V. Collados ◽  
Laura Remón
Keyword(s):  
Healthy Subjects ◽  
Spatial Information ◽  
Blind Deconvolution ◽  
Imaging System ◽  
Retinal Imaging ◽  
Optical Quality ◽  
Retinal Images ◽  
Image Sharpness ◽  
Deconvolution Algorithm ◽  
Spread Function

The optical quality of an image depends on both the optical properties of the imaging system and the physical properties of the medium in which the light travels from the object to the final imaging sensor. The analysis of the point spread function of the optical system is an objective way to quantify the image degradation. In retinal imaging, the presence of corneal or cristalline lens opacifications spread the light at wide angular distributions. If the mathematical operator that degrades the image is known, the image can be restored through deconvolution methods. In the particular case of retinal imaging, this operator may be unknown (or partially) due to the presence of cataracts, corneal edema, or vitreous opacification. In those cases, blind deconvolution theory provides useful results to restore important spatial information of the image. In this work, a new semi-blind deconvolution method has been developed by training an iterative process with the Glare Spread Function kernel based on the Richardson-Lucy deconvolution algorithm to compensate a veiling glare effect in retinal images due to intraocular straylight. The method was first tested with simulated retinal images generated from a straylight eye model and applied to a real retinal image dataset composed of healthy subjects and patients with glaucoma and diabetic retinopathy. Results showed the capacity of the algorithm to detect and compensate the veiling glare degradation and improving the image sharpness up to 1000% in the case of healthy subjects and up to 700% in the pathological retinal images. This image quality improvement allows performing image segmentation processing with restored hidden spatial information after deconvolution.

High-Resolution Retinal Imaging System with Dual Deformable Mirrors

2015 ◽  
Vol 35 (5) ◽  
pp. 0501004 ◽  
Author(s):  
肖飞 Xiao Fei ◽  
戴云 Dai Yun ◽  
赵军磊 Zhao Junlei ◽  
赵豪欣 Zhao Haoxin ◽  
周虹 Zhou Hong ◽  
...  
Keyword(s):  
High Resolution ◽  
Imaging System ◽  
Retinal Imaging ◽  
Deformable Mirrors

scholarly journals Rapid Single Image-Based DTM Estimation from ExoMars TGO CaSSIS Images Using Generative Adversarial U-Nets

2021 ◽  
Vol 13 (15) ◽  
pp. 2877
Author(s):  
Yu Tao ◽  
Siting Xiong ◽  
Susan J. Conway ◽  
Jan-Peter Muller ◽  
Anthony Guimpier ◽  
...  
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
Imaging System ◽  
Landing Site ◽  
Parameter Tuning ◽  
Processing Parameters ◽  
Input Image ◽  
Large Area ◽  
Laser Altimeter ◽  
Imaging Science

The lack of adequate stereo coverage and where available, lengthy processing time, various artefacts, and unsatisfactory quality and complexity of automating the selection of the best set of processing parameters, have long been big barriers for large-area planetary 3D mapping. In this paper, we propose a deep learning-based solution, called MADNet (Multi-scale generative Adversarial u-net with Dense convolutional and up-projection blocks), that avoids or resolves all of the above issues. We demonstrate the wide applicability of this technique with the ExoMars Trace Gas Orbiter Colour and Stereo Surface Imaging System (CaSSIS) 4.6 m/pixel images on Mars. Only a single input image and a coarse global 3D reference are required, without knowing any camera models or imaging parameters, to produce high-quality and high-resolution full-strip Digital Terrain Models (DTMs) in a few seconds. In this paper, we discuss technical details of the MADNet system and provide detailed comparisons and assessments of the results. The resultant MADNet 8 m/pixel CaSSIS DTMs are qualitatively very similar to the 1 m/pixel HiRISE DTMs. The resultant MADNet CaSSIS DTMs display excellent agreement with nested Mars Reconnaissance Orbiter Context Camera (CTX), Mars Express’s High-Resolution Stereo Camera (HRSC), and Mars Orbiter Laser Altimeter (MOLA) DTMs at large-scale, and meanwhile, show fairly good correlation with the High-Resolution Imaging Science Experiment (HiRISE) DTMs for fine-scale details. In addition, we show how MADNet outperforms traditional photogrammetric methods, both on speed and quality, for other datasets like HRSC, CTX, and HiRISE, without any parameter tuning or re-training of the model. We demonstrate the results for Oxia Planum (the landing site of the European Space Agency’s Rosalind Franklin ExoMars rover 2023) and a couple of sites of high scientific interest.

scholarly journals Ultra-High-Resolution 1 m/pixel CaSSIS DTM Using Super-Resolution Restoration and Shape-from-Shading: Demonstration over Oxia Planum on Mars

2021 ◽  
Vol 13 (11) ◽  
pp. 2185
Author(s):  
Yu Tao ◽  
Sylvain Douté ◽  
Jan-Peter Muller ◽  
Susan J. Conway ◽  
Nicolas Thomas ◽  
...  
Keyword(s):  
High Resolution ◽  
3D Reconstruction ◽  
Imaging System ◽  
Processing System ◽  
Digital Terrain Model ◽  
Super Resolution ◽  
Landing Site ◽  
Shape From Shading ◽  
Stereo Pair ◽  
Terrain Model

We introduce a novel ultra-high-resolution Digital Terrain Model (DTM) processing system using a combination of photogrammetric 3D reconstruction, image co-registration, image super-resolution restoration, shape-from-shading DTM refinement, and 3D co-alignment methods. Technical details of the method are described, and results are demonstrated using a 4 m/pixel Trace Gas Orbiter Colour and Stereo Surface Imaging System (CaSSIS) panchromatic image and an overlapping 6 m/pixel Mars Reconnaissance Orbiter Context Camera (CTX) stereo pair to produce a 1 m/pixel CaSSIS Super-Resolution Restoration (SRR) DTM for different areas over Oxia Planum on Mars—the future ESA ExoMars 2022 Rosalind Franklin rover’s landing site. Quantitative assessments are made using profile measurements and the counting of resolvable craters, in comparison with the publicly available 1 m/pixel High-Resolution Imaging Experiment (HiRISE) DTM. These assessments demonstrate that the final resultant 1 m/pixel CaSSIS DTM from the proposed processing system has achieved comparable and sometimes more detailed 3D reconstruction compared to the overlapping HiRISE DTM.

Pontine ataxic hemiparesis studied by a high-resolution magnetic resonance imaging system

1987 ◽  
Vol 21 (2) ◽  
pp. 204-207 ◽  
Author(s):  
Hidehiko Nabatame ◽  
Hidenao Fukuyama ◽  
Ichiro Akiguchi ◽  
Masakuni Kameyama ◽  
Kazumasa Nishimura ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Imaging System ◽  
Magnetic Resonance Imaging System ◽  
Resonance Imaging ◽  
Ataxic Hemiparesis
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