共查询到19条相似文献,搜索用时 406 毫秒
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基于MSR和边缘提取的彩色图像融合新方法 总被引:3,自引:0,他引:3
提出了基于多尺度Retinex(MSR)和边缘提取实施彩色图像融合的一种新方法。多尺度Retinex算法具有突出图像中阴暗区域信息的功能,采用边缘检测的方法提取图像中阴暗区域,将原图像阴暗区域的像素替换成多尺度Retinex增强图像的像素实现彩色图像融合,得到的新图像信息更丰富。在提取闭合区域时,提出了区分真断点和准断点的技术,改进了闭合边缘提取的方法。进而对融合的新图像进行了深入研究,获得埃及Giza金字塔中最大的Khufu金字塔阴影的几何信息。 相似文献
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针对海洋合成孔径雷达(SAR)图像结构信息不明显、水下目标识别困难这一问题,提出了基于经验模式分解(EMD)的算法和H(o)lder指数调整相融合的框架,该框架可以有效地滤除海洋SAR图像的斑点噪声并增强其结构信息,使得人眼可以分辨其特征信息.该融合框架利用EMD将海洋SAR图像分解成不同频率成分的分量,不同层次的分量根据其结构信息和噪声的特征用不同的H(o)lder指数来调整,H(o)lder指数的大小随着分量层数的增加而减小,即在不同尺度下分别抑制斑点噪声,从而恢复其中所包含的结构信息.试验结果表明,利用该框架可以有效抑制SAR图像中的斑点噪声和增强与水下目标相关的结构信息,使人眼可以分辨海洋SAR图像的特征结构. 相似文献
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本文在分析小波变换的基础上,将小波分析应用到目标图像的融合跟踪技术上,利用小波的多尺度和多分辨特性,不仅能够获得不同分辨力下的图像序列,进行目标图像融合;还能有效地从信号中提取突变信号。对函数或信号进行多尺度的细化分析。图像边缘用小波变换进行处理和提取并对图像形心进行计算。能够得到较好的轮廓提取效果和形心定位精度,进而说明了小波变换可能成为目标跟踪中较好的数学方法。 相似文献
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基于线奇异性分析的图像边缘检测方法 总被引:1,自引:0,他引:1
针对基于图像像素点分析的边缘提取方法存在无法同时满足高抑噪性、连续性,定位性等问题,本文提出了方向Beamle变换(DBT)方法,在定义图像线奇异性的理论基础上,利用DBT对图像进行线奇异性分析,依据Beamlet变换具有的线段提取能力,将图像边缘检测问题转化为方向Beamlet变换系数矩阵中奇异点的检测问题,以降低噪声点对边缘检测结果的影响.通过对人工图像以及SAR图像的实验,与经典边缘检测算子相比较,验证了本方法具有较强的抗噪性,特别是针对直线边缘,在抑制噪声影响的同时保证了线状边缘的直线连接性,抗噪性较强. 相似文献
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基于边缘检测的SAR图像平行线特征提取算法 总被引:1,自引:0,他引:1
针对传统平行线定义的局限性,本文提出了一种平行线对模型,并以该模型为核心,设计了一种基于边缘检测的SAR(SyntheticAperture Radar,SAR)图像平行线特征提取算法.在图像经过滤波预处理后,首先采用具有恒虚警特性的ROEWA(Ratio of Exponentially Weighted Averages,ROEWA)算子得到边缘检测图,再利用提出的平行线基元提取算法进行检测,最后基于启发式连接的思想连接断点.实验结果表明,该算法能有效地提取SAR图像中的平行线性结构,可以进一步应用于道路网、机场跑道、河流等大型组合线性目标的自动识别中. 相似文献
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The synthetic aperture radar (SAR) images are mainly affected by speckle noise. Speckle degrades the features in the image and reduces the ability of a human observer to resolve fine detail, hence despeckling is very much required for SAR images. This paper presents speckle noise reduction in SAR images using a combination of curvelet and fuzzy logic technique to restore speckle-affected images. This method overcomes the limitation of discontinuity in hard threshold and permanent deviation in soft threshold. First, it decomposes noise image into different frequency scales using curvelet transform, and then applies the fuzzy shrinking technique to high-frequency coefficients to restore noise-contaminated coefficients. The proposed method does not use threshold approach only by proper selection of shrinking parameter the speckle in SAR image is suppressed. The experiment is carried out on different resolutions of RISAT-1 SAR images, and results are compared with the existing filtering algorithms in terms of noise mean variance (NMV), mean square difference (MSD), equal number of looks (ENL), noise standard deviation (NSD) and speckle suppression index (SSI). A comparison of the results shows that the proposed technique suppresses noise significantly, preserves the details of the image and improves the visual quality of the image. 相似文献
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基于EEMD的SAR海洋内波参数反演 总被引:1,自引:0,他引:1
经验模态分解(EMD)方法对非平稳信号进行分解,容易出现模式混叠和边界效应,从而不能得到有物理意义的特征信息.集成经验模态分解(EEMD)能够有效地克服模式混叠和边界效应问题,可准确地提取信号的本质特征信息.在分析SAR图像反演海洋内波参数机理的基础上,本文提出了一种基于EEMD的海洋内波参数反演方法.实验结果表明:与小波分解和EMD方法相比,该方法能更有效地克服模式混叠现象,所提取的分量更接近内波波动的物理本质,所反演的内波参数与经验数据吻合. 相似文献
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A novel approach to obtain precise segmentation of synthetic aperture radar (SAR) images using Markov random field model on region adjacency graph (MRF-RAG) is presented. First, to form a RAG, the watershed algorithm is employed to obtain an initially over-segmented image. Then, a novel MRF is defined over the RAG instead of pixels so that the erroneous segmentation caused by speckle in SAR images can be avoided and the number of configurations for the combinatorial optimisation can be reduced. Finally, a modification method based on Gibbs sampler is proposed to correct edge errors, brought by the over-segmented algorithm, in the segmentations obtained by MRF-RAG. The experimental results both on simulated and real SAR images show that the proposed method can reduce the computational complexity greatly as well as increase the segmentation precision. 相似文献
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Tria M. Ovarlez J.P. Vignaud L. Castelli J.C. Benidir M. 《Radar, Sonar & Navigation, IET》2007,1(1):27-37
New technique based on continuous wavelet transform (CWT) for classifying objects in synthetic aperture radar (SAR) imaging is presented. The CWT allows to analyse two-dimensional SAR images to highlight the frequency and angular behaviour of the scatterers. This technique allows to build a SAR hyperimage, that is, a four-dimensional data cube which represents for each spatial location (x, y) of the scatterer in the image, its frequency and angular energy behaviour. When analysing different targets, objects or areas in SAR images, it has been recently observed that some scatterers belonging to a same class of objects could have similar frequency and angular energy responses. The previous observations have motivated the determination to exploit these energy responses to discriminate these objects. This discrimination is performed by frequency and angular correlations between the response of a particular scatterer (measured) and those of all the scatterers in the SAR image. Some examples of discrimination from real SAR data are presented and show an interest of the method for target classification and recognition for SAR imaging 相似文献
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提高分辨率的带宽外推SAR成像算法 总被引:1,自引:0,他引:1
分析了合成孔径雷达(SAR)的图像信号模型,阐述了应用数据外推方法提高分辨率的可行性.提出一种最小方差谱估计和最小加权范数约束结合的非参数类数据外推方法.该方法外推SAR相位历史域信号有效带宽可得到较好的成像效果.仿真和实测数据处理证明了此方法的有效性,并给出了定量比较与分析. 相似文献
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水下小目标精细成像对于正确识别水下目标具有重要意义。目前,多波束成像声呐和条带合成孔径声呐是获取水下小目标图像的主要手段。水下目标的判别主要利用了目标图像的亮点特征,即使是同一目标从不同方位观测时得到的结果也可能差异较大,这给快速识别确认目标带来了困难。为解决该问题,提出了利用圆周合成孔径声呐对水下小目标进行水声层析成像信号处理方法,提高了声呐的多角度融合观测能力。仿真及试验数据处理结果表明,合成孔径声呐层析成像方法能够获得目标外形轮廓精细特征,有利于水下小目标的正确识别。 相似文献