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Improving night sky star image processing algorithm for star sensors

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS image SCIENCE AND VISION 2014年第4期31卷 794-801页

作者： Arbabmir, Mohammad Vali Mohammadi, Seyyed Mohammad Salahshour, Sadegh Somayehee, Farshad Amirkabir Univ Technol Tehran Iran Shiraz Univ Technol Shiraz Iran Khaje Nasir Toosi Univ Technol Tehran Iran

In this paper, the night sky star image processing algorithm, consisting of image preprocessing, star pattern recognition, and centroiding steps, is improved. It is shown that the proposed noise reduction approach can preserve more necessary information than other frequently used approaches. It is also shown that the proposed thresholding method unlike commonly used techniques can properly perform image binarization, especially in images with uneven illumination. Moreover, the higher performance rate and lower average centroiding estimation error of near 0.045 for 400 simulated images compared to other algorithms show the high capability of the proposed night sky star image processing algorithm. (c) 2014 Optical Society of America

关键词： image metrics image processing image processing algorithms Low light levels Noise reduction Pattern recognition

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Ordered subsets convex algorithm and automatic image processing sequences: The solid bases for 3D THz inspection 7th

Ordered subsets convex algorithm and automatic image process...

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International Symposium on Ultrafast Phenomena and Terahertz Waves, ISUPTW 2014

作者： Balacey, H. Perraud, J.-B. Bou Sleiman, J. Recur, B. Mounaix, P. LOMA Bordeaux University CNRS-UMR 5798 351 cours de la Libération Talence33405 France Noctylio S.A.S 59 cours de l'Intendance Bordeaux33000 France Australian National University Dept Applied Maths RSPE Canberra Australia

In the field of non-destructive testing, Terahertz (THz) tomography is a modern imaging technique permitting 3D inspection of opaque objects. A tomographic procedure reconstructs a 3D volume of the acquired object by intersecting the data contained on the projection set. This depth information is extracted from several projections acquired around the object at different viewing angles. This property has made THz tomography a complementary technique to X-Rays. Several reconstruction methods have been investigated for THz tomography [1] but they must be adapted to THz wave properties. For monochromatic source, Beer-Lambert law describes the attenuation encountered by THz waves through the sample and measured on the detector, when reflexion and refraction effects are neglected. Then, as their complements in X-Ray tomography, we investigate in this paper on a Maximum-Likelihood expectation-maximization for TRansmission tomography (ML-TR) compatible with THz radiations. This method, based on Poisson distribution model of measured radiations, takes into account the Gaussian propagation of THz beam [2] and allows introducing some a priori knowledge about the imaged object. Especially, we focus on the implementation denoted Ordered Subsets Convex (OSC) algorithm since it has an efficient convergence rate despite of the noise level and the sparsity of acquired data [3]. We discuss how this new reconstruction is able to estimate physical properties of samples acquired with a 100GHz/300GHz scanner in addition to the 3D reconstruction. Moreover, we present an innovative data and image processing sequence to perform non-destructive inspection from 3D terahertz (THz) images. After a 3D tomographic reconstruction of a sample, a preset segmentation affords the different regions of interest (ROI) composing the inert part of sample. Then a 3D visualization and dimensional measurements could be performed on these ROI, separately, in order to provide new informations of the studied sam

关键词： image processing image processing algorithms Nondestructive testing Segmentation Three dimensional reconstruction Tomography

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Mid-infrared imaging system based on polarizers for detecting marine targets covered in sun glint

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Optics express 2016年第15期24卷 16396-409页

作者： Huijie Zhao Zheng Ji Ying Zhang Xiaofeng Sun Pengfei Song Yansong Li School of Instrumentation Science & Opto-electronics Engineering Beihang University 37 Xueyuan Road Haidian Beijing 100191 China China Academy of Space Technology 104 Youyi Road Haidian Beijing 100094 China

When a marine target is detected by a mid-infrared detector on a sunny day, the target's information could be lost if it is located in sun glint. Therefore, we developed a new mid-infrared imaging system capable of effectively detecting marine targets in regions of strong sun glint, which is presented in this report. Firstly, the theory of the analysis methods employed in different detection scenarios is briefly described to establish whether one or two polarizers should be utilized to suppress further the p-polarized component of sun glint. Secondly, for the case in which a second polarizer is employed, the formula for the optimum angle between the two polarizers is given. Then, the results of our field experiment are presented, demonstrating that the developed system can significantly reduce sun glint and can enhance the contrast of target images. A commonly used image processing algorithm proved capable of identifying a target in sun glint, confirming the effectiveness of our proposed mid-infrared polarization imaging system.

关键词： Analytical techniques image detection systems image processing image processing algorithms Polarimetric imaging Wire grid polarizers

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Toward omnidirectional and automated imaging system for measuring oceanic whitecap coverage

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Journal of the Optical Society of America. A, Optics, image science, and vision 2016年第8期33卷 1589-97页

作者： Raied S Al-Lashi School of Food Science and Nutrition Faculty of Mathematics and Physical Sciences University of Leeds Leeds UK (R.Al-lashi@leeds.ac.uk)

Accurate measurements of oceanic whitecap coverage from whitecap images are required for better understanding air-gas transfer and aerosol production processes. However, this is a challenging task because whitecap patches are formed immediately after a wave breaks and are spread over a wide area. The main challenges in designing whitecaps imaging instrument are the small field of view of the camera lens, processing huge numbers of images, recording data over long time periods, and deployment difficulties in stormy conditions. This paper describes the hardware design of a novel high-resolution optical instrument for imaging oceanic whitecaps and the automated algorithm processing the collected images. The instrument was successfully deployed in 2013 as part of the HiWINGS campaign in the North Atlantic Ocean. The instrument uses a fish-eye camera lens to image the whitecaps in a wide angle of view (180°).

关键词： Camera calibration image processing image processing algorithms image quality Imaging techniques Solar radiation

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Rapid assembly of gold nanoparticle-based microstructures using optically-induced electrokinetics

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OPTICAL MATERIALS EXPRESS 2014年第11期4卷 2368-2380页

作者： Liang, Wenfeng Liu, Lianqing Lai, Sam Hok-Sum Wang, Yuechao Lee, Gwo-Bin Li, Wen Jung Chinese Acad Sci Shenyang Inst Automat State Key Lab Robot Shenyang 110016 Peoples R China Shenyang Jianzhu Univ Sch Transportat & Mech Engn Shenyang 110168 Peoples R China City Univ Hong Kong Dept Mech & Biomed Engn Hong Kong Hong Kong Peoples R China Natl Tsing Hua Univ Dept Power Mech Engn Hsinchu Taiwan

This paper presents a rapid approach for assembling gold nanoparticles (AuNPs)-based microstructures using optically-induced electrokinetics. Results showed that number of AuNPs in the assembled microstructures could be controlled by adjusting the input optically-induced electrokinetics parameters. The formation conditions were experimentally investigated by varying several key electrokinetics parameters, and the results were compared to a numerical simulation of the electrokinetic forces. The experimental results were also analyzed by counting the number of deposited AuNPs in a microstructure using an image processing algorithm. We will show that the optimal parameters for this optoelectronic AuNPs assembly method are electric field frequency range from 9 to 11 kHz with a voltage range of 18-20 V-pp, and an optical exposure time of similar to 120 s. (C) 2014 Optical Society of America

关键词： High numerical aperture optics image processing algorithms Nanopositioning equipment Numerical simulation Solar cell efficiency Thin films

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Influence of lenslet number on performance of image restoration algorithms for the TOMBO imaging system

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OPTICS EXPRESS 2014年第7期22卷 8298-8308页

作者： Gao, Yuan Dong, Lizhi Yang, Ping Tang, Guomao Xu, Bing Chinese Acad Sci Inst Opt & Elect Lab Adapt Opt Chengdu 610209 Peoples R China Chinese Acad Sci Key Lab Adapt Opt Chengdu 610209 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China

In this paper the influence of the number of lenslets on the performance of image restoration algorithms for the thin observation module by bound optics (TOMBO) imaging system was investigated, and the lenslet number was optimized to achieve thin system and high imaging performance. Subimages with different numbers of lenslets were generated following the TOMBO observation model, and image restoration algorithms were applied to evaluate the imaging performance of the TOMBO system. The optimal lenslet number was determined via theoretical performance optimization and verified via experimental comparisons of angular resolutions of two TOMBO systems and a conventional single-lens system. (C) 2014 Optical Society of America

关键词： image processing image processing algorithms image quality image quality assessment image restoration Imaging systems

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Using image processing algorithms for Energy Efficient Routing Algorithm in Sensor Networks

Using Image Processing Algorithms for Energy Efficient Routi...

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Computation World - Future Computing, Service Computation, Cognitive, Adaptive, Content, Patterns Conference

作者： Gilg, Marc Yousef, Yaser Lorenz, Pascal Univ Haute Alsace F-68000 Colmar France

ISBN: (纸本)9781424451661

Energy consumption is a major problem in Wireless Sensor Networks (WSNs) because energy resources of sensors are limited. Several protocols have been created to solve this problem. The main objective of these protocols is to maximize the connectivity and network lifetime. Therefore, the choice of the routing algorithm that delivers packets in a wireless sensor network has to be done in a way to preserve energy. This paper presents a novel adaptive routing algorithm based on image processing algorithm, which utilizes the gradient to select a more energy efficient path.

关键词： wireless sensor network image processing algorithms adaptive energy efficient routing Sobel algorithm AODV routing protocol

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Object-independent structural image analysis: History and modern approaches

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JOURNAL OF OPTICAL TECHNOLOGY 2014年第11期81卷 642-650页

作者： Lutsiv, V. R. Malashin, R. O. St Petersburg Natl Res Univ Informat Technol Mech St Petersburg Russia SI Vavilov State Opt Inst St Petersburg Russia

This paper discusses the history of the appearance and development of structural image analysis. The characteristic disadvantages and advantages of the structural methods that are used and the prerequisites for improving them are analyzed for each of the historical stages. The material culminates with a description of the features of the organization and possibilities of the optimum modern algorithms for structural analysis and a treatment of directions in which they can be improved further. (C) 2015 Optical Society of America.

关键词： image analysis image processing algorithms image recognition devices Machine vision Neural networks Remote sensing

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Axially distributed sensing with a monoscopic imaging lens for single-shot distance measurements

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APPLIED OPTICS 2014年第22期53卷 5078-5083页

作者： Sandner, Marc Kolenovic, Ervin Klattenhoff, Reiner Kolenovic, Elam Elandaloussi, Frank von Kopylow, Christoph Bergmann, Ralf B. BIAS Bremer Inst Angew Strahltechn GmbH D-28359 Bremen Germany Syperion GmbH & Co KG D-28199 Bremen Germany VEW Vereinigte Elekt Werkstatten GmbH D-28357 Bremen Germany Univ Bremen Fac Phys & Elect Engn D-28359 Bremen Germany

Using the image-based optical measurement method known as axially distributed sensing ( ADS), the depth information of a scene is retrieved by evaluating images recorded with a camera positioned on multiple points along a common optical axis. We describe the design of a monoscopic lens that images the scene from two different on-axis points of perspective simultaneously onto a single camera. Designed for use in a territorial surveillance video system, this lens allows for capturing 3D scene information based on ADS with a single shot. We present the physical foundations of this approach and its implementation as a compact lens system and show the usability of the system prototype, supported by performance tests. (C) 2014 Optical Society of America

关键词： Geometric optics image processing algorithms image quality Imaging systems Optical measurement Optical systems

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Flame spectra-temperature estimation based on a color imaging camera and a spectral reconstruction technique

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APPLIED OPTICS 2014年第28期53卷 6351-6361页

作者： Carlos, Toro N. Luis, Arias P. Torres, Sergio Sbarbaro, Daniel Univ Concepcion Dept Elect Engn Concepcion Chile Univ Concepcion Ctr Opt & Photon Concepcion Chile

In this paper a low-cost, practical pixel-based flame spectrum and temperature estimation system based on flame color images is proposed. A spectral resolution of similar to 0.4 nm is achieved with an optical system formed by a color camera, a linear model, a flame's spectral training data, and a spectral reconstruction procedure. As a proof of concept, the estimated spectra are compared to local measurements performed with a commercial spectrometer. In order to estimate the absolute flame-temperature maps, two radiometric images at different wavelengths are reconstructed and the two-color pyrometry method is applied. Experiments show errors of about 2.0% over the estimated temperature, making this system a practical tool for flame sensing in combustion-process monitoring. (C) 2014 Optical Society of America

关键词： CCD cameras Color imaging image processing algorithms Multispectral imaging Optical components Optical systems

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