检索结果-内蒙古大学图书馆

Computer-vision based intelligent adaptive transmission for optical wireless communication

OPTICS EXPRESS 2019年第6期27卷 7979-7987页

作者： Huang, Zhitong Zu, Lijia Zhou, Zihao Tang, Xiao Ji, Yuefeng Beijing Univ Posts & Telecommun SICE State Key Lab Informat Photon & Opt Commun IPOC Beijing 100876 Peoples R China

Optical wireless communication (OWC) has been presented as a promising candidate for future space-air-ground-ocean-integrated communication. However, the OWC is quite sensitive to the variation of the channel transmission characteristics. The light beam absorption and the scattering in the transmission media affect not only the channel feature, but also the imaging quality. Thus, there is an inherent relationship between the OWC performance and the optical imaging quality. Based on this consideration we firstly present the idea of introducing computer vision mechanisms into the OWC systems, and then propose a computer vision-based multi-domain cooperative adjustment (CV-MDCA) mechanism's functional modules to realize the intelligent adaptive transmission in OWC systems. The CV-MDCA mechanism arc specifically designed, with the emphasis on how to quantitatively determine the exact on-line channel quality from the captured images by using effective computer vision schemes. Two groups of experiments, the indoor-simulated underwater visible light communication and the outdoor-practical atmospheric free-space optics, arc implemented in order to evaluate the presented CV-MDCA mechanism's performance. The results not only validate the feasibility to determine the channel quality, according to the captured channel images, but also reveal the presented three computer vision-based criteria's limitations. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

关键词： Edge detection image processing image processing algorithms image quality Nonlinear impairments Optical wireless communication

来源：评论

学校读者我要写书评

暂无评论

Discrimination of image signals on a background of bimodal Gaussoid pulsed noise, optimal by the combined-limitation criterion

引用

JOURNAL OF OPTICAL TECHNOLOGY 2010年第4期77卷 245-252页

作者： Samoilin, E. A. Chief Marshall Artillery MI Nedelin Rostov Mil In Rostov Na Donu Russia

algorithms have been developed for discriminating image signals on a background of bimodal Gaussoid pulse noise under conditions of complete a priori indeterminacy concerning the image-signal distribution. The algorithms are based on a new optimality criterion that combines the minimum of the unconditional skip probability with the maximum correct-detection probability at limited levels of unconditional false-alarm and correct-nondetection probabilities. The results of numerical studies of algorithms are presented that show that they are of higher quality than known nonoptimal procedures, as well as than the optimal algorithm under the condition of complete a priori signal indeterminacy. (C) 2010 Optical Society of America.

关键词： algorithms Continuous variables Digital imaging image processing algorithms image reconstruction Imaging noise

来源：评论

学校读者我要写书评

暂无评论

Joint artifact correction and super-resolution of image slicing and mapping system via a convolutional neural network

引用

OPTICS EXPRESS 2021年第5期29卷 7247-7260页

作者： Liu, Anqi Zeng, Xianzi Yuan, Yan Su, Lijuan Wang, Wanyue Beihang Univ Key Lab Precis Optomechatron Technol Minist Educ Beijing 100191 Peoples R China

As the key component of the image mapping spectrometer, the image mapper introduces complex image degradation in the reconstructed images, including low spatial resolution and intensity artifacts. In this paper, we propose a novel image processing method based on the convolutional neural network to perform artifact correction and super-resolution (SR) simultaneously. The proposed joint network contains two branches to handle the artifact correction task and SR task in parallel. The artifact correction module is designed to remove the artifacts in the image and the SR module is used to improve the spatial resolution. An attention fusion module is constructed to combine the features extracted by the artifact correction and SR modules. The fused features are used to reconstruct an artifact-free high-resolution image. We present extensive simulation results to demonstrate that the proposed joint method outperforms state-of-the-art methods and can be generalized to other image mapper designs. We also provide experimental results to prove the efficiency of the joint network. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

关键词： image processing image processing algorithms image quality Neural networks Spatial resolution Spectral imaging

来源：评论

学校读者我要写书评

暂无评论

Underwater image restoration based on adaptive parameter optimization of the physical model

引用

OPTICS EXPRESS 2023年第13期31卷 21172-21191页

作者： Ning, Yu Jin, Yong-ping Peng, You-duo Yan, Jian Hunan Univ Sci & Technol Natl Local Joint Engn Lab Marine Mineral Resources Xiangtan 411201 Hunan Peoples R China

Underwater images have the advantage of carrying high information density and are widely used for marine information acquisition. Due to the complex underwater environment, the captured images are often unsatisfactory and often suffer from color distortion, low contrast, and blurred details. Physical model-based methods are often used in relevant studies to obtain clear underwater images;however, water selectively absorbs light, making the use of a priori knowledge-based methods no longer applicable and thus rendering the restoration of underwater images ineffective. Therefore, this paper proposes an underwater image restoration method based on adaptive parameter optimization of the physical model. Firstly, an adaptive color constancy algorithm is designed to estimate the background light value of underwater image, which effectively guarantees the color and brightness of underwater image. Secondly, aiming at the problem of halo and edge blur in underwater images, a smoothness and uniformity transmittance estimation algorithm is proposed to make the estimated transmittance smooth and uniform, and eliminate the halo and blur of the image. Then, in order to further smooth the edge and texture details of the underwater image, a transmittance optimization algorithm for smoothing edge and texture details is proposed to make the obtained scene transmittance more natural. Finally, combined with the underwater image imaging model and histogram equalization algorithm, the image blurring is eliminated and more image details are retained. The qualitative and quantitative evaluation on the underwater image dataset (UIEBD) shows that the proposed method has obvious advantages in color restoration, contrast and comprehensive effect, and has achieved remarkable results in application testing. It shows that the proposed method can effectively restore underwater degraded images and provide a theoretical basis for the construction of underwater imaging models.& COPY;2023 Optica Publis

关键词： Fast Fourier transforms image processing image processing algorithms image quality Optical imaging Underwater imaging

来源：评论

学校读者我要写书评

暂无评论

Solar eclipse skies and limb reddening

引用

APPLIED OPTICS 2020年第21期59卷 F78-F84页

作者： Gedzelman, Stanley David CUNY City Coll Dept Earth & Atmospher Sci New York NY 10031 USA CUNY City Coll NOAA CREST Ctr New York NY 10031 USA

During solar eclipses the sunlit tops of cloud layers and arctic sea ice near the umbra appear salmon-brown when viewed from airplanes or satellites. Under these conditions, the clouds and atmosphere are illuminated by light restricted to the solar limb, which has effective radiating temperatures as low as 4000 K. The resulting limb reddening largely accounts for the color. A second-order scattering model is used to simulate the color of photographs of cloud tops taken from a flight during the 21 August 2017 eclipse and MODIS Aqua and Terra satellite "true color" images during the 2 July 2019 eclipse. These observed color changes provide data that has potential value in determining the vertical temperature profile of the solar photosphere. (C) 2020 Optical Society of America

关键词： Blackbodies image processing algorithms Light wavelength Optical depth Rayleigh scattering Visible light

来源：评论

学校读者我要写书评

暂无评论

Investigation on slice direction dependent detectability of volumetric cone beam CT images

引用

OPTICS EXPRESS 2016年第4期24卷 3749-3764页

作者： Han, Minah Lee, Changwoo Park, Subok Baek, Jongduk Yonsei Univ Sch Integrated Technol Inchon South Korea Yonsei Univ Yonsei Inst Convergence Technol Inchon South Korea US FDA Silver Spring MD USA

We investigate the detection performance of transverse and longitudinal planes for various signal sizes (i.e., 1 mm to 8 mm diameter spheres) in cone beam computed tomography (CBCT) images. CBCT images are generated by computer simulation and images are reconstructed using an FDK algorithm. For each slice direction and signal size, a human observer study is conducted with a signal-known-exactly/background-known-exactly (SKE/BKE) binary detection task. The detection performance of human observers is compared with that of a channelized Hotelling observer (CHO). The detection performance of an ideal linear observer is also calculated using a CHO with Laguerre-Gauss (LG) channels. The detectability of high contrast small signals (i.e., up to 4-mm-diameter spheres) is higher in the longitudinal plane than the transverse plane. It is also shown that CHO performance correlates well with human observer performance in both transverse and longitudinal plane images. (C) 2016 Optical Society of America

关键词： Computer simulation image processing algorithms image quality image quality assessment Imaging systems Reconstruction algorithms

来源：评论

学校读者我要写书评

暂无评论

Three-dimensional single-photon imaging through obscurants

引用

OPTICS EXPRESS 2019年第4期27卷 4590-4611页

作者： Tobin, Rachael Halimi, Abderrahim McCarthy, Aongus Laurenzis, Martin Christnacher, Frank Buller, Gerald S. Heriot Watt Univ Sch Engn & Phys Sci Edinburgh EH14 4AS Midlothian Scotland French German Res Inst St Louis 5 Rue Gen Cassagnou F-68301 St Louis France

We investigate the depth imaging of objects through various densities of different obscurants (water fog. glycol-based vapor, and incendiary smoke) using a time-correlated single-photon detection system which had an operating wavelength of 1550 nm and an average optical output power of approximately 1.5 mW. It consisted of a monostatic scanning transceiver unit used in conjunction with a picosecond laser source and an individual Peltier-cooled InGaAs/InP single-photon avalanche diode (SPAD) detector. We acquired depth and intensity data of targets imaged through distances of up to 24 meters for the different obscurants. We compare several statistical algorithms which reconstruct both the depth and intensity images for short data acquisition times, including very low signal returns in the photon-starved regime. (C) Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License.

关键词： Atmospheric scattering Attenuation coefficient image processing algorithms image quality Laser beam propagation Optical components

来源：评论

学校读者我要写书评

暂无评论

Optomechanical design of a portable compact bidirectional texture function measurement instrument

引用

APPLIED OPTICS 2017年第4期56卷 1183-1193页

作者： Hosek, Jan Havran, Vlastimil Nemcova, Sarka Bittner, Jiri Cap, Jiri Czech Tech Univ Fac Mech Engn Dept Instrumentat & Control Engn Tech 4 CR-16635 Prague Czech Republic Czech Tech Univ Fac Elect Engn Dept Comp Graph & Interact Karlovo Nam 13 CR-16635 Prague Czech Republic

Recent developments in optoelectronics and material processing techniques make it possible to design and produce a portable and compact measurement instrument for bidirectional texture function (BTF). Parallelized optics, on-board data processing, rapid prototyping, and other nonconventional production techniques and materials were the key to building an instrument capable of in situ measurements with fast data acquisition. We designed, built, and tested a prototype of a unique portable and compact multi-camera system for BTF measurement which is capable of in situ measurement of temporally unstable samples. In this paper, we present its optomechanical design. (C) 2017 Optical Society of America

关键词： image processing algorithms Optical components Optical standards Optomechanical design Optomechanics Surface light scattering

来源：评论

学校读者我要写书评

暂无评论

Interferometer response characterization algorithm for multi-aperture Fabry-Perot imaging spectrometers

引用

OPTICS EXPRESS 2023年第14期31卷 23066-23085页

作者： Picone, Daniele Gousset, Silvere Dalla Mura, Mauro Ferrec, Yann Le Coarer, Etienne Univ Grenoble Alpes GIPSA lab CNRS Grenoble INP F-38000 Grenoble France Univ Grenoble Alpes CNRS IPAG F-38000 Grenoble France Inst Univ France IUF F-75005 Paris France Off Natl Etud & Rech Aerosp DOTA BP 80100Chemin Huniere F-91123 Palaiseau France

In recent years, the demand for hyperspectral imaging devices has grown significantly, driven by their ability of capturing high-resolution spectral information. Among the several possible optical designs for acquiring hyperspectral images, there is a growing interest in interferometric spectral imaging systems based on division of aperture. These systems have the advantage of capturing snapshot acquisitions while maintaining a compact design. However, they require a careful calibration to operate properly. In this work, we present the interferometer response characterization algorithm (IRCA), a robust three-step procedure designed to characterize the transmittance response of multi-aperture imaging spectrometers based on the interferometry of Fabry-Perot. Additionally, we propose a formulation of the image formation model for such devices suitable to estimate the parameters of interest by considering the model under various regimes of finesse. The proposed algorithm processes the image output obtained from a set of monochromatic light sources and refines the results using nonlinear regression after an ad-hoc initialization. Through experimental analysis conducted on four different prototypes from the image SPectrometer On Chip (ImSPOC) family, we validate the performance of our approach for characterization. The associated source code for this paper is available from Zenodo (http://***/10.5281/zenodo.7978514).& COPY;2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

关键词： Hyperspectral imaging image processing algorithms Imaging systems Medical imaging Optical components Optical design

来源：评论

学校读者我要写书评

暂无评论

Automatic traffic monitoring by φ-OTDR data and Hough transform in a real-field environment

引用

APPLIED OPTICS 2021年第13期60卷 3579-3584页

作者： Catalano, Ester Coscetta, Agnese Cerri, Enis Cennamo, Nunzio Zeni, Luigi Minardo, A. Univ Campania Luigi Vanvitelli Dept Engn Via Roma 29 I-81031 Averse Italy

In this paper, we demonstrate automatic vehicle detection and counting by processing data acquired using a phase-sensitive optical time-domain reflectometer (phi-OTDR) distributed optical fiber sensor. The acquired data are processed using the Hough transform, which detects the lines in the images formed by representing the acquired data in the space-time domain. A rough classification of the vehicles (heavy versus light vehicles) is also proposed, based on the amplitude of the vibration data along the detected lines. The method has been experimentally tested by performing phi-OTDR measurements along a telecommunication fiber cable running in a buried conduit along the state road SS18 (province of Salerno, Italy), opened to normal traffic. Comparison with ground-truth data, manually generated by inspecting video recordings, allowed us to estimate a vehicle detection success rate up to 73%, while heavy vehicles were fully detected. (C) 2021 Optical Society of America

关键词： Amplified spontaneous emission Fiber optic cables image processing algorithms Optical sensing Optical time domain reflectometry Phase retrieval

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：