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- 摘要
- 关键词
- 实验方案
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过滤筛选
- 2015
- Bessel Function
- Coupling Coefficient
- Fusion temperature and Elongation speed
- Physics
- UIN Suska Riau
- University of Riau
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Improving Hypersharpening for WorldView-3 Data
摘要: In this letter, hypersharpening is analyzed in depth by investigating some weaknesses present in its formulation. It is shown that the key formula of the synthesized band variant can be simplified under certain circumstances. In addition, a novel fusion schema is proposed. As a result, the gain factor adopted to weight the injected detail is computed in a different way. This schema can be applied to fuse a wide range of hyperspectral and multispectral data. In this letter, its effectiveness is demonstrated by taking into account the characteristics of WorldView-3 data.
关键词: pansharpening,image fusion,WorldView-3,remote sensing,Hypersharpening
更新于2025-09-04 15:30:14
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Multi-resolution Image Fusion in Remote Sensing () || Introduction
摘要: One of the major achievements of human beings is the ability to record observational data in the form of photographs, a science which dates back to 1826. Humans have always tried to reach greater heights (treetops, mountains, platforms, and so on) to observe phenomenon of interest, to decide on habitable places, farming and such other activities. Curiosity motivates human beings to take photographs of the earth from elevated platforms. In the initial days of photography, balloons, pigeons, and kites were used to capture such photographs. With the invention of the aircraft in 1903, the ?rst aerial photograph on a stable platform was made possible in 1909 [120]. In the 1960s and 1970s, the primary platform that was used to carry remote sensing instruments shifted from aircraft to satellites [120]. It was during this period that the word ‘remote sensing’ replaced the frequently used word ‘aerial photograph’. Satellites can cover wider land space than planes and can monitor areas on a regular basis.
关键词: image fusion,remote sensing,satellites,aerial photograph,hyper-spectral images,multi-spectral images,panchromatic image
更新于2025-09-04 15:30:14
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Multi-resolution Image Fusion in Remote Sensing () || Literature Review
摘要: In many remote sensing applications, the spatial information of a fused image is as important as the spectral information. In other words, it is necessary to have images that have the spectral resolution of multi-spectral (MS) images and the spatial resolution of a panchromatic image. A sensor with spatial and spectral resolution, at the same time is hardly feasible [139]. The coarse spatial resolution of MS images is the result of a trade off due to physical and technical constraints. The quantity of light energy which arrives onto the detector is proportional to the width of its spectral range and hence, is smaller in the MS sensor than in the Pan sensor. It is therefore necessary to increase the energy that impinges onto the MS detector to obtain acceptable signal-to-noise ratio. However, this is not possible due to technological limitations. Further, if the MS images had high spatial resolution, the amount of data to transmit would be larger. The difficulties in on-board storage and data transmission to the ground also restrict the spatial resolution of MS images. This makes the remote sensing satellite sensors acquire MS images with low spatial resolution and the Pan image with high spatial resolution. Thus, the MS images have high spectral but low spatial resolution and the Pan image has high spatial but low spectral resolution.
关键词: image fusion,remote sensing,spectral resolution,spatial resolution,multi-spectral images,panchromatic image,Pan-sharpening
更新于2025-09-04 15:30:14
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An advanced technique of fabricating multi silica directional fiber coupler
摘要: We have investigated the optimum parameter to fabricate multi fiber of silica material for directional coupler based on fusion and elongation techniques. Coupling coefficient between the fibers was derived by using Hankel and Bessel function. However, the fusion temperature was experimentally determined as function of elongation speed. Good performance of multi fiber coupler has been obtained for fabrication parameters of fusion temperature and elongation speed of 1350 oC and 125 μm/s respectively. The proposed coupling coefficient shows a better accuracy with empirical one for various coupling length. It is exponentially increased by reducing the distance between fibers. Finally, the microscopic analysis of coupling region deformation has shown that the silica material was well dispersed and distributed.
关键词: Multi silica fiber coupler,coupling coefficient,fusion and elongation techniques
更新于2025-09-04 15:30:14
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Multi-resolution Image Fusion in Remote Sensing () || Image Fusion Using Different Edge-preserving Filters
摘要: In this chapter, we discuss fusion approaches using two edge-preserving filters, namely, guided filter and difference of Gaussians (DoGs). Since the MS and Pan images have high spectral and high spatial resolutions, respectively, one can obtain the resultant fused image using these two images by injecting the missing high frequency details from the Pan image into the MS image. The quality of the final fused image will then depend on the method used for the extraction of high frequency details and also on the technique for injecting those details into the MS image. In the literature on multi-resolution image fusion, various approaches have been proposed based on the aforementioned process that also include state-of-the-art methods such as additive wavelet luminance proportional (AWLP) [178] and generalized Laplacian pyramid-context based decision (GLP-CBD) [13]. Motivated by these works, we first address the fusion problem by using different edge-preserving filters in order to extract the high frequency details from the Pan image. Specifically, we have chosen the guided filter and difference of Gaussians (DoGs) for detail extraction since these are more versatile in applications involving feature extraction, denoising, etc.
关键词: image fusion,multi-resolution,edge-preserving filters,remote sensing,guided filter,difference of Gaussians
更新于2025-09-04 15:30:14
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Multi-resolution Image Fusion in Remote Sensing () || Image Fusion: Model Based Approach with Degradation Estimation
摘要: Recently, many researchers have attempted to solve the problem of multi-resolution image fusion by using model based approaches, with emphasis on improving the fused image quality and reducing color distortion [273, 121]. They model the low resolution (LR) MS image as a blurred and noisy version of its ideal high resolution (HR) fused image. Solving the problem of fusion by the model based approach is desirable since the aliasing present due to undersampling of the MS image can be taken care of while modelling. Fusion using the interpolation of MS images and edge-preserving ?lters as given in Chapter 3 do not consider the effect of aliasing which is due to undersampling of MS images. The aliasing in the acquired image causes distortion and, hence, there exists degradation in the LR MS image. In this chapter, we propose a model based approach in which a learning based method is used to obtain the required degradation matrix that accounts for aliasing. Using the proposed model, the ?nal solution is obtained by considering the model as an inverse problem. The proposed approach uses sub-sampled as well as non sub-sampled contourlet transform based learning and a Markov random ?eld (MRF) prior for regularizing the solution.
关键词: model based approach,multi-resolution image fusion,degradation estimation,contourlet transform,Markov random field
更新于2025-09-04 15:30:14
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Multi-resolution Image Fusion in Remote Sensing () || Use of Self-similarity and Gabor Prior
摘要: In this chapter, we introduce a concept called self-similarity and use the same for obtaining the initial fused image. We also use a new prior called Gabor prior for regularizing the solution. In Chapter 4, degradation matrix entries were estimated by modelling the relationship between the Pan-derived initial estimate of the fused MS image and the LR MS image. This may lead to inaccurate estimate of the final fused image since we make use of the Pan data suffering from low spectral resolution in getting the initial estimate. However, if we derive the initial fused image using the available LR MS image, which has high spectral resolution, mapping between LR and HR would be better and the derived degradation matrix entries are more accurate. This makes the estimated degradation matrix better represent the aliasing since we now have an initial estimate that has both high spatial and spectral resolutions. To do this, we need to obtain the initial estimate using only the available LR MS image since the true fused image is not available. We perform this by using the property of natural images that the probability of the availability of redundant information in the image and its downsampled versions is high [89]. We exploit this self-similarity in the LR observation and the sparse representation theory in order to obtain the initial estimate of the fused image. Finally, we solve the Pan-sharpening or multi-resolution image fusion problem by using a model based approach in which we regularize the solution by proposing a new prior called the Gabor prior.
关键词: sparse representation theory,multi-resolution image fusion,Gabor prior,self-similarity,Pan-sharpening
更新于2025-09-04 15:30:14
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A Novel Multi-Exposure Image Fusion Method Based on Adaptive Patch Structure
摘要: Multi-exposure image fusion methods are often applied to the fusion of low-dynamic images that are taken from the same scene at different exposure levels. The fused images not only contain more color and detailed information, but also demonstrate the same real visual effects as the observation by the human eye. This paper proposes a novel multi-exposure image fusion (MEF) method based on adaptive patch structure. The proposed algorithm combines image cartoon-texture decomposition, image patch structure decomposition, and the structural similarity index to improve the local contrast of the image. Moreover, the proposed method can capture more detailed information of source images and produce more vivid high-dynamic-range (HDR) images. Speci?cally, image texture entropy values are used to evaluate image local information for adaptive selection of image patch size. The intermediate fused image is obtained by the proposed structure patch decomposition algorithm. Finally, the intermediate fused image is optimized by using the structural similarity index to obtain the ?nal fused HDR image. The results of comparative experiments show that the proposed method can obtain high-quality HDR images with better visual effects and more detailed information.
关键词: texture information entropy,adaptive selection,multi-exposure image fusion,patch structure decomposition
更新于2025-09-04 15:30:14
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Data Fusion of Two Hyperspectral Imaging Systems with Complementary Spectral Sensing Ranges for Blueberry Bruising Detection
摘要: Currently, the detection of blueberry internal bruising focuses mostly on single hyperspectral imaging (HSI) systems. Attempts to fuse different HSI systems with complementary spectral ranges are still lacking. A push broom based HSI system and a liquid crystal tunable filter (LCTF) based HSI system with different sensing ranges and detectors were investigated to jointly detect blueberry internal bruising in the lab. The mean reflectance spectrum of each berry sample was extracted from the data obtained by two HSI systems respectively. The spectral data from the two spectroscopic techniques were analyzed separately using feature selection method, partial least squares-discriminant analysis (PLS-DA), and support vector machine (SVM), and then fused with three data fusion strategies at the data level, feature level, and decision level. The three data fusion strategies achieved better classification results than using each HSI system alone. The decision level fusion integrating classification results from the two instruments with selected relevant features achieved more promising results, suggesting that the two HSI systems with complementary spectral ranges, combined with feature selection and data fusion strategies, could be used synergistically to improve blueberry internal bruising detection. This study was the first step in demonstrating the feasibility of the fusion of two HSI systems with complementary spectral ranges for detecting blueberry bruising, which could lead to a multispectral imaging system with a few selected wavelengths and an appropriate detector for bruising detection on the packing line.
关键词: data fusion,blueberry,hyperspectral imaging,bruising
更新于2025-09-04 15:30:14
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A micro-scale plasma spectrometer for space and plasma edge applications (invited)
摘要: A plasma spectrometer design based on advances in lithography and microchip stacking technologies is described. A series of curved plate energy analyzers, with an integrated collimator, is etched into a silicon wafer. Tests of spectrometer elements, the energy analyzer and collimator, were performed with a 5 keV electron beam. The measured collimator transmission and energy selectivity were in good agreement with design targets. A single wafer element could be used as a plasma processing or fusion first wall diagnostic.
关键词: electron beam,microchip stacking,silicon wafer,plasma processing,fusion first wall diagnostic,lithography,plasma spectrometer,collimator,energy analyzer
更新于2025-09-04 15:30:14