检索结果-内蒙古大学图书馆

A high-precision binocular 3D reconstruction system based on depth-of-field extension and feature point guidance

MEASUREMENT 2025年 248卷

作者： Lyu, Yuxing Liu, Zongming Wang, Junhua Jiang, Ying Li, Yidan Li, Xinglong Kong, Lingbao Li, Jing Xu, Min Fudan Univ Dept Opt Sci & Engn Shanghai 200438 Peoples R China Fudan Univ Inst Optoelect Shanghai Frontiers Sci Res Base Intelligent Optoel Shanghai 200438 Peoples R China Shanghai Aerosp Control Technol Inst Shanghai 201109 Peoples R China Shanghai Key Lab Space Intelligent Control Technol Shanghai 201109 Peoples R China

Limited depth of field (DOF) restricts high-precision 3D reconstruction in large volumes using binocular stereo vision. wavefront coding (WFC) generates intermediate images with consistent point spread function (PSF) over a large DOF that are processed into clear final images by decoding algorithms, making it ideal for large-DOF 3D reconstruction. In this paper, we develop a binocular stereo vision system based on WFC. By combining back propagation (BP) neural network with adaptive genetic algorithm (AGA), the system addresses the problems of high computational cost and high instability of traditional calibration methods. Using calibration results, a twostep correction method for binocular distortion and epipolar correction guided by feature points is designed, which improves matching efficiency and accuracy. Combined with an end-to-end stereo matching network, our system achieves high-precision 3D reconstruction within a depth range of 0.3 m- 2.3 m, significantly enhancing reconstruction stability and accuracy. Additionally, the average total execution time from image acquisition to final 3D reconstruction is approximately 0.223 s, demonstrating the system's efficiency for real-time applications.

关键词： 3D reconstruction Binocular stereo vision wavefront coding Depth of field Camera calibration Feature point

来源：评论

学校读者我要写书评

暂无评论

Dual Band Computational Infrared Spectroscopy via Large Aperture Meta-Optics

引用

ACS PHOTONICS 2023年第4期10卷 986-992页

作者： Froch, Johannes E. Colburn, Shane Zhan, Alan Han, Zheyi Fang, Zhuoran Saxena, Abhi Huang, Luocheng Bohringer, Karl F. Majumdar, Arka Univ Washington Dept Phys Seattle WA 98195 USA Univ Washington Dept Elect & Comp Engn Seattle WA 98195 USA Tunoptix Seattle WA 98195 USA Univ Washington Dept Bioengn Seattle WA 98195 USA Univ Washington Inst Nanoengn Syst Seattle WA 98195 USA

An important challenge in contemporary photonics research is the miniaturization of optical components and devices to facilitate their deployment in more compact and energy-efficient mobile platforms. As spectrometers are one of the most essential tools for optical measurements, a particularly strong demand exists to find new concepts to replace commonly used spectrometers, which are typically bulky and therefore often impractical for mobile applications. Arrays of subwavelength scatterers, also known as meta-optics, engineered to shape and manipulate transmitted optical wavefronts provide a particularly appealing solution for this problem. Herein, the concept of a computational spectrometer is presented where strongly chromatic point spread functions of a high-efficiency double helix meta-optic are utilized in combination with a computational back end to accurately reconstruct optical spectra. This is demonstrated in two different infrared wavelength ranges (1260-1360 nm and 1480-1640 nm), while achieving a spectral resolution of & SIM;3.5 nm, underlining the potential of a small footprint meta-optical spectrometer.

关键词： dielectric metasurface computational spectrometer wavefront coding computational reconstruction spectrometer miniaturization

来源：评论

学校读者我要写书评

暂无评论

wavefront coded image restoration algorithm based on compressed sensing for off-axis mirror system 7

Wavefront coded image restoration algorithm based on compres...

引用

7th Asia Pacific Conference on Optics Manufacture (APCOM)

作者： Yi, Huang Jun, Chang Li Dongmei Cao Jiajing Shan, Du Beijing Inst Technol Beijing 100081 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China Chinese Acad Sci Inst Semicond Beijing 100083 Peoples R China

ISBN: (数字)9781510652095

ISBN: (纸本)9781510652095;9781510652088

By combining optical systems and image processing, wavefront coding can greatly expand the depth of focus and depth of field of optical systems. It has been widely used in iris detection, high-power microscopic objective lens, infrared optical system athermalized, and so on. At present, the image restoration algorithms commonly used in wavefront coding are based on deconvolution, Wiener filtering, and so on. Although these algorithms can achieve an excellent image restoration effect, they will also bring boundary ringing effects and artifacts to the image. When the image is disturbed by strong noise, the restoration effect will also be seriously affected. To solve these problems, a wavefront coded image restoration algorithm based on compressed sensing is proposed in this paper. The strong data reconstruction ability of the compressed sensing restoration algorithm is used to restore the encoded image obtained by the wavefront coding system. This method can effectively suppress noise and reconstruct the image without artifact and boundary ringing effect. Through the comparison of simulation results, the effectiveness of the proposed method is verified.

关键词： wavefront coding compressed sensing artifact

来源：评论

学校读者我要写书评

暂无评论

Restoration of encoded images by a trefoil phase mask using deep learning 25

Restoration of encoded images by a trefoil phase mask using ...

引用

Conference on Current Developments in Lens Design and Optical Engineering XXV

作者： Reyes-Alfaro, Jose M. Toxqui-Quitl, Carina Espejel-Rivera, Maria A. Gonzalez-Amador, Enrique Padilla-Vivanco, Alfonso Univ Politecn Tulancingo Comp Vis Lab Ingn 100 Tulancingo De Bravo 43629 Hidalgo Mexico

ISBN: (纸本)9781510679221;9781510679238

Depth of field (DoF) determines the focused object depth in an optical imaging system. An extended depth of field (EDoF) should provide a larger axial resolution without significantly sacrificing the spatial resolution of the image. An optical-computational technique that uses a Trefoil phase mask (PM) to optically encode the scene and a convolutional neural network (CNN) to restore the acquired encoded image is presented. Simulations and experimental results are compared.

关键词： Convolutional Neural Network Trefoil Phase Mask Extended Depth of Field Deblurring wavefront coding

来源：评论

学校读者我要写书评

暂无评论

Learning Optimal wavefront Shaping for Multi-Channel Imaging

引用

IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE 2021年第7期43卷 2179-2192页

作者： Nehme, Elias Ferdman, Boris Weiss, Lucien E. Naor, Tal Freedman, Daniel Michaeli, Tomer Shechtman, Yoav Technion Israel Inst Technol Viterbi Fac Elect Engn Biomed Engn Dept IL-3200003 Haifa Israel Technion Israel Inst Technol Lorry I Lokey Ctr Life Sci & Engn IL-3200003 Haifa Israel Technion Israel Inst Technol Russel Berrie Nanotechnol Inst Biomed Engn Dept IL-3200003 Haifa Israel Technion Israel Inst Technol Russel Berrie Nanotechnol Inst Lorry I Lokey Ctr Life Sci & Engn IL-3200003 Haifa Israel Technion Israel Inst Technol Biomed Engn Dept IL-3200003 Haifa Israel Google Res IL-3508504 Haifa Israel Technion Israel Inst Technol Viterbi Fac Elect Engn IL-3200003 Haifa Israel

Fast acquisition of depth information is crucial for accurate 3D tracking of moving objects. Snapshot depth sensing can be achieved by wavefront coding, in which the point-spread function (PSF) is engineered to vary distinctively with scene depth by altering the detection optics. In low-light applications, such as 3D localization microscopy, the prevailing approach is to condense signal photons into a single imaging channel with phase-only wavefront modulation to achieve a high pixel-wise signal to noise ratio. Here we show that this paradigm is generally suboptimal and can be significantly improved upon by employing multi-channel wavefront coding, even in low-light applications. We demonstrate our multi-channel optimization scheme on 3D localization microscopy in densely labelled live cells where detectability is limited by overlap of modulated PSFs. At extreme densities, we show that a split-signal system, with end-to-end learned phase masks, doubles the detection rate and reaches improved precision compared to the current state-of-the-art, single-channel design. We implement our method using a bifurcated optical system, experimentally validating our approach by snapshot volumetric imaging and 3D tracking of fluorescently labelled subcellular elements in dense environments.

关键词： Imaging Three-dimensional displays Microscopy Location awareness Optical microscopy Optical imaging Optical diffraction Computational microscopy wavefront coding deep neural networks end-to-end optimization

来源：评论

学校读者我要写书评

暂无评论

A Vehicle Detection Method under Strong Infrared Radiation Interference 23

A Vehicle Detection Method under Strong Infrared Radiation I...

引用

Proceedings of the 2023 7th International Conference on Video and Image Processing

作者： Yuan Zhang Ziyi Chen Luping Wang Wuming Wu School of Electronics and Communication Engineering Sun Yat-sen University China

ISBN: (纸本)9798400709388

Strong infrared radiation interference is a common type of interference in optoelectronic countermeasures. An optical system exposed to strong light would disrupt the acquisition of image information and even damage the device. In this paper, we aim to design an infrared system for object detection under the circumstances of strong infrared radiation interference in order to enhance the countermeasure capability of the optoelectronic system. Firstly, we introduce the Wave-front coding (WFC) technique to attenuate the damage caused by strong infrared radiation interference. Secondly, we use L₂ (Tikhonov) regularization to restore the blurred image caused by wavefront coding and obtain a clear low-light image. Thirdly, we use Recursively Separated and Weighted Histogram Equalization (RSWHE) for image enhancement to improve its contrast. Finally, we use the YOLOv8 algorithm for object detection. Experiments on real infrared images show that this scheme has outstanding performance under strong infrared radiation interference.

关键词： Image Enhancement Image Restoration Infrared Image Object Detection wavefront coding

来源：评论

学校读者我要写书评

暂无评论

Metasurface Generation of Paired Accelerating and Rotating Optical Beams for Passive Ranging and Scene Reconstruction

引用

ACS PHOTONICS 2020年第6期7卷 1529-1536页

作者： Colburn, Shane Majumdar, Arka Univ Washington Dept Elect & Comp Engn Seattle WA 98195 USA Univ Washington Dept Phys Seattle WA 98195 USA

Depth measurements are vital for many emerging technologies with applications in augmented reality, robotics, gesture detection, and facial recognition. These applications, however, demand compact and low-power systems beyond the capabilities of many state-of-the-art depth cameras. While active illumination techniques can enable precise scene reconstruction, they increase power consumption, and systems that employ stereo require extended form factors to separate viewpoints. Here, we exploit a single, spatially multiplexed aperture of nanoscatterers to demonstrate a solution that replicates the functionality of a high-performance depth camera typically comprising a spatial light modulator, polarizer, and multiple lenses. Using cylindrical nanoscatterers that can arbitrarily modify the phase of an incident wavefront, we passively encode two complementary optical responses to depth information in a scene. The designed optical metasurfaces simultaneously generate a focused accelerating beam and a focused rotating beam that exploit wavefront propagation-invariance to produce paired, adjacent images with a single camera snapshot. Compared to conventional depth from defocus methods, this technique enhances both the depth precision and depth of field at the same time. By decoding the captured data in software, our system produces a fully reconstructed image and transverse depth map, providing an optically passive ranging solution. In our reconstruction algorithm, we account for the field curvature of our metasurface by calculating the change in Gouy phase over the field of view, enabling a fractional ranging error of 1.7%. We demonstrate a precise, visible wavelength, and polarization-insensitive metasurface depth camera with a compact 2 mm(2) aperture.

关键词： computational imaging depth sensors metasurfaces extended depth of focus ranging wavefront coding

来源：评论

学校读者我要写书评

暂无评论

Simultaneous Achromatic and Varifocal Imaging with Quartic Metasurfaces in the Visible

引用

ACS PHOTONICS 2020年第1期7卷 120-127页

作者： Colburn, Shane Majumdar, Arka Univ Washington Dept Elect & Comp Engn Seattle WA 98195 USA Univ Washington Dept Phys Seattle WA 98195 USA

Two key metrics for imaging systems are their magnification and optical bandwidth. While high-quality imaging systems today achieve bandwidths spanning the whole visible spectrum and large changes in magnification via optical zoom, these often entail lens assemblies with bulky elements unfit for size-constrained applications. Metalenses present a methodology for miniaturization, but their strong chromatic aberrations and the lack of a varifocal, achromatic element limit their utility. Although exemplary broadband achromatic metalenses are realizable via dispersion engineering, in practice, these designs are limited to small physical apertures as large area lenses would require phase compensating scatterers with aspect ratios infeasible for fabrication. Many applications, however, necessitate larger areas to collect more photons for better signal-to-noise ratio and furthermore must also operate with unpolarized light. In this paper, we simultaneously achieve achromatic operation at visible wavelengths and varifocal control using a polarization-insensitive, hybrid optical-digital system with area unconstrained by dispersion-engineered scatterers. We derive phase equations for a pair of conjugate metasurfaces that generate a focused accelerating beam for chromatic focal shift control and a wide tunable focal length range of 4.8 mm (a 667-diopter change). Utilizing this conjugate pair, we realize a near spectrally invariant point spread function across the visible regime. We then combine the metasurfaces with a postcapture deconvolution algorithm to image full-color patterns under incoherent white light, demonstrating an achromatic 5x zoom range. Simultaneously achromatic and varifocal metalenses could have applications in various fields including augmented reality, implantable microscopes, and machine vision sensors.

关键词： metasurfaces computational imaging tunable metasurfaces varifocal lens achromatic metasurface wavefront coding

来源：评论

学校读者我要写书评

暂无评论

Lensless broadband diffractive imaging with improved depth of focus: wavefront modulation by multilevel phase masks

引用

JOURNAL OF MODERN OPTICS 2019年第3期66卷 335-352页

作者： Katkovnik, Vladimir Ponomarenko, Mykola Egiazarian, Karen Tampere Univ Technol Lab Signal Proc Korkeakoulunkatu 10 FI-33720 Tampere Finland

This paper introduces a novel lensless full colour diffractive computational imaging system with a planar Multilevel Phase Mask (MPM) as a diffractive optical element (DOE). The novelty concerns: a methodology of MPM design for improved depth of focus (DoF);design of PSFs for RGB imaging and an inverse imaging algorithm with sparse colour image modelling simultaneous for all RGB channels. MPMs are step-wise invariant. The cubic wavefront coding (WFC) is incorporated in MPMs with optimization of number of levels and width of invariant steps. This design of MPM makes the system robust with respect to defocus (improves DoF) and diminish chromatic aberrations typical for DOEs. Broadband multichannel test-images are exploited for design and testing of the lensless system. We consider two alternative optical setups: Wavelength Multiplexing (WM) and Wavelength Division (WD). In WM, the light beam is broadband multichannel with light sources radiating all wavelengths simultaneously and a CMOS sensor is equipped with a Bayer colour filter array (CFA) for registration of spectral measurements. In this setup, a single MPM is designed for the broadband multichannel light beams. In WD, separate exposures of RGB channels are registered by a broadband grey-scale CCD sensor. Different MPMs are designed for each of the RGB channels. Simulation experiments demonstrate the essentially extended DoF of the designed lensless systems and the advanced accuracy and quality of imaging with respect to the corresponding WM and WD systems with refractive lenses. Due to robustness of the designed lensless system to chromatic aberrations, this advantage has a place even with respect to the lens-system.

关键词： Multilevel diffractive optical elements multilevel phase mask design wavefront coding extended depth of focus computational imaging chromatic aberrations inverse imaging

来源：评论

学校读者我要写书评

暂无评论

Theoretical and experimental analysis of co-designed binary phase masks for enhancing the depth of field of panchromatic cameras

引用

OPTICAL ENGINEERING 2021年第3期60卷 033101-033101页

作者： Fontbonne, Alice Sauer, Herve Goudail, Francois Univ Paris Saclay Inst Opt Grad Sch Lab Charles Fabry CNRS Palaiseau France

We investigate the depth of field (DoF) enhancing capacity of binary annular phase masks embedded in panchromatic imaging systems. We first demonstrate with numerical simulations and real-world imaging experiments that phase masks optimized for monochromatic illumination are somewhat robust to their use under wide spectrum illumination: they provide images that are slightly less sharp but less affected by deconvolution artifacts due to spectral averaging. Then, we show that masks specifically optimized for wide spectrum illumination perform better under this type of illumination than monochromatically optimized phase masks under monochromatic illumination, especially when the targeted DoF range is large. This interesting effect comes from the fact that deconvolution artifacts are significantly reduced by wide spectrum illumination. These results show that it is useful to take into account the illumination spectrum together with the scene characteristics and the targeted DoF range for effective codesign of DoF enhancing imaging systems. (C) 2021 Society of Photo-Optical Instrumentation Engineers (SPIE)

关键词： image processing binary phase masks deconvolution optical system codesign wavefront coding experimental validation

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

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

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：