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多跳网路由算法研究
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作者 王晓明 《兰州铁道学院学报》 2000年第6期1-3,共3页
多跳网的路由算法是波分复用网的研究热点之一 .本文提出了多跳网的新的路由算法 ,克服了目前诸多算法的不足 .并给出了算法的光波图描述 .
关键词 波分复用 多跳网 路由算法 光波图 通信
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Fluorescence molecular imaging system and fusion algorithm based on 2CCD camera
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作者 王玉 王明泉 +1 位作者 杨晓峰 王艳翔 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2016年第2期161-164,共4页
Infrared and visible light images can be obtained simultaneously by building fluorescence imaging system,which includes fluorescence excitation,images acquisition,mechanical part,image transmission and processing sect... Infrared and visible light images can be obtained simultaneously by building fluorescence imaging system,which includes fluorescence excitation,images acquisition,mechanical part,image transmission and processing section.This system studied the 2charge-coupled device(CCD)camera(AD-080CL)of the JAI company.Fusion algorithm of visible light and near infrared images was designed for the fluorescence imaging system with wavelet transform image fusion algorithm.In order to enhance the fluorescent moiety of the fusion image,the luminance value of the green component of the color image was changed.And using microsoft foundation classes(MFC)application architecture,the supporting software system was bulit in VS2010 environment. 展开更多
关键词 fluorescence imaging system image fusion wavelet transform microsoft foundation classes(MFC)
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Comparison Between Four Methods for Data Fusion of ETM+ Multispectral and Pan Images 被引量:4
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作者 Pouran Behnia 《Geo-Spatial Information Science》 2005年第2期98-103,共6页
Four data fusion methods, principle component transform (PCT), brovey transform (BT), smoothing filter-based intensity modulation(SFIM), and hue, saturation, intensity (HSI), are used to merge Landsat-7 ETM+ multispec... Four data fusion methods, principle component transform (PCT), brovey transform (BT), smoothing filter-based intensity modulation(SFIM), and hue, saturation, intensity (HSI), are used to merge Landsat-7 ETM+ multispectral bands with ETM+ panchromatic band. Each of them improves the spatial resolution effectively but distorts the original spectral signatures to some extent. SFIM model can produce optimal fusion data with respect to preservation of spectral integrity. However, it results the most blurred and noisy image if the coregistration between the multispectral and pan images is not accurate enough. The spectral integrity for all methods is preserved better if the original multispectral images are within the spectral range of ETM+ pan image. 展开更多
关键词 data fusion ETM+ multispectral PC transform SFIM
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Parameterized first-guess spectrum method for retrieving directional spectrum of swell-dominated waves and huge waves from SAR images 被引量:9
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作者 孙建 管长龙 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2006年第1期12-20,共9页
A method to retrieve ocean wave spectra from SAR images, named Parameterized First-guess Spectrum Method (PFSM), was proposed after interpretation of the theory to ocean wave imaging and analysis of the drawbacks of... A method to retrieve ocean wave spectra from SAR images, named Parameterized First-guess Spectrum Method (PFSM), was proposed after interpretation of the theory to ocean wave imaging and analysis of the drawbacks of the retrieving model generally used. In this method, with additional information and satellite parameters, the separating wave-number is first calculated to determine the maximum wave-number beyond which the linear relation can be used. The separating wave-number can be calculated using the additional information on wind velocity and parameters of SAR satellite. And then the SAR spectrum can be divided into SAR spectrum of wind wave and of swell according to the result of separating wave-number. The portion of SAR spectrum generated by wind wave, is used to search for the most suitable parameters of ocean wind wave spectrum, including propagation direction of ocean wave, phase speed of dominating wave and the angle spreading coefficient. The swell spectrum is acquired by directly inversing the linear relation of ocean wave spectrum to SAR spectrum given the portion of SAR spectrum generated by swell. We used the proposed method to retrieve the ocean wave spectrum from ERS-SAR data from the South China Sea and compared the result with altimeter data. The agreement indicates that the PFSM is reliable. 展开更多
关键词 Synthetic Aperture Radar ocean wave spectrum SAR retrieval method
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MULTI-SPECTRAL AND HYPERSPECTRAL IMAGE FUSION USING 3-D WAVELET TRANSFORM 被引量:5
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作者 Zhang Yifan He Mingyi 《Journal of Electronics(China)》 2007年第2期218-224,共7页
Image fusion is performed between one band of multi-spectral image and two bands of hyperspectral image to produce fused image with the same spatial resolution as source multi-spectral image and the same spectral reso... Image fusion is performed between one band of multi-spectral image and two bands of hyperspectral image to produce fused image with the same spatial resolution as source multi-spectral image and the same spectral resolution as source hyperspeetral image. According to the characteristics and 3-Dimensional (3-D) feature analysis of multi-spectral and hyperspectral image data volume, the new fusion approach using 3-D wavelet based method is proposed. This approach is composed of four major procedures: Spatial and spectral resampling, 3-D wavelet transform, wavelet coefficient integration and 3-D inverse wavelet transform. Especially, a novel method, Ratio Image Based Spectral Resampling (RIBSR)method, is proposed to accomplish data resampling in spectral domain by utilizing the property of ratio image. And a new fusion rule, Average and Substitution (A&S) rule, is employed as the fusion rule to accomplish wavelet coefficient integration. Experimental results illustrate that the fusion approach using 3-D wavelet transform can utilize both spatial and spectral characteristics of source images more adequately and produce fused image with higher quality and fewer artifacts than fusion approach using 2-D wavelet transform. It is also revealed that RIBSR method is capable of interpolating the missing data more effectively and correctly, and A&S rule can integrate coefficients of source images in 3-D wavelet domain to preserve both spatial and spectral features of source images more properly. 展开更多
关键词 Image fusion 3-Dimensional (3-D) wavelet transform MULTI-SPECTRAL HYPERSPECTRAL
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Simple PSF based method for pupil phase mask’s optimization in wavefront coding system 被引量:2
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作者 ZHANG Wen-zi CHEN Yan-ping +2 位作者 ZHAO Ting-yu YE Zi YU Fei-hong 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第2期180-185,共6页
By applying the wavefront coding technique to an optical system, the depth of focus can be greatly increased. Several complicated methods, such as Fisher Information based method, have already been taken to optimize f... By applying the wavefront coding technique to an optical system, the depth of focus can be greatly increased. Several complicated methods, such as Fisher Information based method, have already been taken to optimize for the best pupil phase mask in ideal condition. Here one simple point spread function (PSF) based method with only the standard deviation method used to evaluate the PSF stability over the depth of focus is taken to optimize for the best coefficients of pupil phase mask in practical optical systems. Results of imaging simulations for optical systems with and without pupil phase mask are presented, and the sharpness of image is calculated for comparison. The optimized results showed better and much more stable imaging quality over the original system without changing the position of the image plane. 展开更多
关键词 Wavefront coding Pupil phase mask Depth of focus PSF stability OPTIMIZATION SHARPNESS Imaging simulation
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Analysis of Spectral Characteristics Based on Optical Remote Sensing and SAR Image Fusion 被引量:4
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作者 Weiguo LI Nan JIANG Guangxiu GE 《Agricultural Science & Technology》 CAS 2014年第11期2035-2038,2040,共5页
Because of cloudy and rainy weather in south China, optical remote sens-ing images often can't be obtained easily. With the regional trial results in Baoying, Jiangsu province, this paper explored the fusion model an... Because of cloudy and rainy weather in south China, optical remote sens-ing images often can't be obtained easily. With the regional trial results in Baoying, Jiangsu province, this paper explored the fusion model and effect of ENVISAT/SAR and HJ-1A satel ite multispectral remote sensing images. Based on the ARSIS strat-egy, using the wavelet transform and the Interaction between the Band Structure Model (IBSM), the research progressed the ENVISAT satel ite SAR and the HJ-1A satel ite CCD images wavelet decomposition, and low/high frequency coefficient re-construction, and obtained the fusion images through the inverse wavelet transform. In the light of low and high-frequency images have different characteristics in differ-ent areas, different fusion rules which can enhance the integration process of self-adaptive were taken, with comparisons with the PCA transformation, IHS transfor-mation and other traditional methods by subjective and the corresponding quantita-tive evaluation. Furthermore, the research extracted the bands and NDVI values around the fusion with GPS samples, analyzed and explained the fusion effect. The results showed that the spectral distortion of wavelet fusion, IHS transform, PCA transform images was 0.101 6, 0.326 1 and 1.277 2, respectively and entropy was 14.701 5, 11.899 3 and 13.229 3, respectively, the wavelet fusion is the highest. The method of wavelet maintained good spectral capability, and visual effects while improved the spatial resolution, the information interpretation effect was much better than other two methods. 展开更多
关键词 Spectral characteristics Data fusion SAR Multi-spectral image Wavelet transform
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Window shrink contourlet coefficients for image denoising 被引量:2
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作者 金炜 潘英俊 +1 位作者 魏彪 冯鹏 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2005年第5期540-543,共4页
An adaptive image denosing technique was proposed to achieve the tradeoff between details retain and noises removal. In order to achieve this objective, the contourlet transform was introduced and a new threshold meth... An adaptive image denosing technique was proposed to achieve the tradeoff between details retain and noises removal. In order to achieve this objective, the contourlet transform was introduced and a new threshold method, namely CWinShrink, is presented. It shrinks the contourlet coefficients with adaptive shrinkage factors. The shrinkage factors were calculated with reference to the sum of squares of the contourlet coefficients within the neighborhood window. This approach achieves enhanced results for images those are corrupted with additive Gaussian noise. In numerical comparisons with various methods, for a set of noisy images (the PSNR range fi'om 10.86dB to 26.91dB) , the presented method outperforms VisuShrink and Wiener filter in terms of the PSNR. Experiments also show that this method not only keeps the details of image but also yields denoised images with better visual quality. 展开更多
关键词 contourlet transform wavelet transfotTn CWinShrink image denoising
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Chromaticity Characteristics of Fluorescent Dyes in Cloth
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作者 李戎 陈东辉 《Journal of Donghua University(English Edition)》 EI CAS 2004年第4期78-81,共4页
Chromaticity characteristics of several fluorescent dyes in cloth were studied in terms of chromaticity diagram. The dominant wavelength and color purity of the samples were calculated and chromaticity diagrams were d... Chromaticity characteristics of several fluorescent dyes in cloth were studied in terms of chromaticity diagram. The dominant wavelength and color purity of the samples were calculated and chromaticity diagrams were drawn to provide countermeasures with which the perceptual color attributes such as hue and saturation are correlated. 展开更多
关键词 chromaticity diagram fluorescent dyes dominant wavelength color purity.
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Phase Spectral Analysis of EEG Signals
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作者 YOURong-yi CHENZhong 《Chinese Journal of Biomedical Engineering(English Edition)》 2004年第3期126-133,共8页
A new method of phase spectral analysis of EEG is proposed for the comparative analysis of phase spectra between normal EEG and epileptic EEG signals based on the wavelet decomposition technique. By using multiscale w... A new method of phase spectral analysis of EEG is proposed for the comparative analysis of phase spectra between normal EEG and epileptic EEG signals based on the wavelet decomposition technique. By using multiscale wavelet decomposition,the original EEGs are mapped to an orthogonal wavelet space,such that the variations of phase can be observed at multiscale. It is found that the phase (and phase difference) spectra of normal EEGs are distinct from that of epileptic EEGs. That is the variations of phase (and phase difference) of normal EEGs have a distinct periodic pattern with the electrical activity proceeds in the brain,but do not the epileptic EEGs. For epileptic EEGs,only at those transient points,the phase variations are obvious. In order to verify these results with the observational data,the phase variations of EEGs in principal component space are observed and found that,the features of phase spectra is in correspondence with that the wavelet space. These results make it possible to view the behavior of EEG rhythms as a dynamic spectrum. 展开更多
关键词 Phase spectral analysis Electroencephalogram (EEG) Wavelet decomposition Principal component analysis
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Junk band recovery for hyperspectral image based on curvelet transform
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作者 孙蕾 罗建书 《Journal of Central South University》 SCIE EI CAS 2011年第3期816-822,共7页
Under consideration that the profiles of bands at close wavelengths are quite similar and the curvelets are good at capturing profiles, a junk band recovery algorithm for hyperspectral data based on curvelet transform... Under consideration that the profiles of bands at close wavelengths are quite similar and the curvelets are good at capturing profiles, a junk band recovery algorithm for hyperspectral data based on curvelet transform is proposed. Both the noisy bands and the noise-free bands are transformed via curvelet band by band. The high frequency coefficients in junk bands are replaced with linear interpolation of the high frequency coefficients in noise-flee bands, and the low frequency coefficients remain the same to keep the main spectral characteristics from being distorted. Jutak bands then are recovered after the inverse curvelet transform. The performance of this method is tested on the hyperspectral data cube obtained by airborne visible/infrared imaging spectrometer (AVIRIS). The experimental results show that the proposed method is superior to the traditional denoising method BayesShrink and the art-of-state Curvelet Shrinkage in both roots of mean square error (RMSE) and peak-signal-to-noise ratio (PSNR) of recovered bands. 展开更多
关键词 hyperspectral image curvelet transform junk band denosing
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Atmospheric correction of remote sensing imagery based on the surface spectrum’s vector space 被引量:1
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作者 CHEN Chun LIU ChengYu ZHANG ShuQing 《Science China Earth Sciences》 SCIE EI CAS 2012年第8期1289-1296,共8页
Due to the atmosphere effect,the qualities of images decrease conspicuously,practically in the visible bands,in the processing of earth observation by the satellite-borne sensors.Thus,removing the atmosphere effects h... Due to the atmosphere effect,the qualities of images decrease conspicuously,practically in the visible bands,in the processing of earth observation by the satellite-borne sensors.Thus,removing the atmosphere effects has become a key step to improve the qualities of images and to retrieve the actual reflectivity of surface features.An atmospheric correction approach,called ACVSS(Atmospheric Correction based Vector Space of Spectrum),is proposed here based on the vector space of the features' spectrum.The reflectance image of each band is retrieved first according to the radiative transfer equation,then the spectrum's vector space is constructed using the infrared bands,and finally the residual errors of the reflectance images in the visible bands are corrected based on the pixel position in the spectrum's vector space.The proposed methodology is verified through atmospheric correction on Landsat-7 ETM+ imagery.The experimental results show that our method is more accurate and the corrected image is more distinct,compared with those offered by current popular atmospheric correction software. 展开更多
关键词 atmospheric correction remote sensing imagery spectrum's vector space Landsat-7 ETM+ imagery ACVSS
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Experimental Study of Perfectly Patterned Silica-Titania Optical Waveguide 被引量:1
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作者 Rimlee DEB ROY Devika SIL +2 位作者 Sunirmal JANA Prasanta Kumar BISWAS Shyamal Kumar BHADRA 《Photonic Sensors》 SCIE EI CAS 2012年第1期81-91,共11页
Inorganic silica-titania thin films with thicknesses 150 nm-200 nm are deposited on high purity and polished silicon wafer and silica glass substrates by sol-gel dipping process and are patterned by capillary force li... Inorganic silica-titania thin films with thicknesses 150 nm-200 nm are deposited on high purity and polished silicon wafer and silica glass substrates by sol-gel dipping process and are patterned by capillary force lithography technique. Subsequently grating structure is embossed in green stage. The patterned gel films are subjected to stepwise heat treatment to 500 ℃ and above in pure oxygen atmosphere in order to achieve major conversion of mixed-gel to oxide optical films which are characterized by Ellipsometry, Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM) to optimize the fabrication parameters and to get perfectly matched film. Removal of organics and formation of perfectly inorganic silica-titania network at optimized heat treatment in controlled environment are ensured by FTIR spectral study. The difference in refractive indices between the substrate and coated film as developed waveguides for operating wavelength show the planar waveguide behavior of the films. calculated theoretically matches exactly with the (632.8 nm) and the measured optical properties 展开更多
关键词 Optical properties sol-gel technique thin films OXIDES
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Nonlinear optical holograms for spatial and spectral shaping of light waves 被引量:7
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作者 Asia Shapira Liran Naor Ady Arie 《Science Bulletin》 SCIE EI CAS CSCD 2015年第16期1403-1415,共13页
Shaping either the spatial or the spectral output of a nonlinear interaction is accomplished by introducing basic concepts of computer-generated holography into the nonlinear optics regime. The possibilities of arbitr... Shaping either the spatial or the spectral output of a nonlinear interaction is accomplished by introducing basic concepts of computer-generated holography into the nonlinear optics regime. The possibilities of arbitrarily spatially shaping the result of a nonlinear interaction are presented for different phase-matching schemes allowing for both one- and two-dimensional shaping. Shaping the spectrum of a beam in nonlinear interaction is also possible by utilizing similar holographic techniques. The novel and complete control of the output of a nonlinear interaction opens exciting options in the fields of particle manipulation, optical communications, spectroscopy and quantum information. 展开更多
关键词 Nonlinear optics Beam shaping Spectral shaping Computer-generated holograms
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