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基于Zernike矩的快速PPB相干斑抑制算法 总被引:1,自引:0,他引:1
应用非局部均值算法到SAR图像相干斑抑制中时存在计算量大、图像自相似性利用不足等缺点,严重制约该类算法的实际应用.针对该问题,提出一种SAR图像快速PPB滤波算法.给出基于积分图的PPB快速算法,引入Zemike矩构造一种图块相似性度量,利用Cosmo实测SAR数据进行实验.实验结果表明,该算法提高了图像自相似特征利用率,显著改善了滤波效果. 相似文献
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异源图像匹配是视觉导航、多源图像融合分析的关键步骤之一,常用的匹配方法是分别从两幅图像中提取特征,再对特征进行匹配。但是对于成像机理差别较大的异源图像,如SAR图像和可见光图像,很难提取到同名特征。提出一种基于多尺度支持度的异源图像匹配方法,只需要从一幅图像中提取多尺度边缘特征,在变换空间中寻找另一幅图像对该特征的最大支持度。支持度的计算采用了标准化梯度强度和的形式。采用遗传算法对支持度函数解空间进行全局寻优来获取最优匹配点。实验结果表明,该方法能有效实现SAR图像和可见光图像的匹配,处理时间能够满足工程要求。 相似文献
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一种高性能SAR图像边缘点特征匹配方法 总被引:3,自引:0,他引:3
针对合成孔径雷达(Synthetic aperture radar,SAR)图像特征匹配中特征提取的不稳定性和相似度优化搜索的复杂性问题,提出了一种精确高效稳健的SAR图像边缘点集匹配方法. 首先,分析了仿射变换模型在遥感图像匹配中的适应性,并对仿射变换模型进行了参数分解;其次,提出了基于方向模板的SAR图像边缘检测算子,并利用SAR图像边缘的梯度和方向特征,建立了基于像素迁移的多源SAR边缘点集相似性匹配准则,以及图像匹配的联合相似度-联合特征均方和(Square summation joint feature,SSJF);然后,利用改进的遗传算法(Genetic algorithm,GA)来进行相似度的全局极值优化搜索,获取变换模型参数和边缘点集的对应关系;最后,从理论上分析了本文方法的性能,并利用多幅SAR图像的匹配实验以及与原有方法的对比分析,对本文方法的性能进行了验证. 相似文献
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针对区域变化检测受分类器精度影响大、无法探测出内部细微变化这一问题,本文提出了基于热含量不变量的合成孔径雷达(Synthetic aperture radar,SAR)图像点特征变化检测.该方法利用热核特征,具有计算简便、矩阵扰动性小的特点,且有效地降低了噪声的干扰.由热核不变量的统计特性,采用期望极大化(Expectation maximization,EM)算法解决了SAR图像的自动变化检测.同时通过对权的讨论,给出了适用于SAR图像的权函数定义.对单波段单极化SAR与多极化SAR图像,本文算法相比于基于像素和似然比的方法,能够更快速更精确地检测到变化区域. 相似文献
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与光学图像相比,SAR图像噪声干扰明显增强,导致光学图像处理领域中常用的尺度不变特征提取算法的稳定性在SAR图像中明显下降。为此,提出一种基于Harris算子的SAR图像尺度不变特征提取方法。该方法首先将单尺度图像特征点检测中具有良好稳定性的Harris算子拓展到多尺度图像域,并结合Harris算子极值点的稳定性分析实现尺度不变特征定位,以提高特征定位的稳定性。进而采用迭代滤波器取代传统卷积滤波器完成特征定位中所需高斯滤波操作,以提高特征定位的速度。最后利用特征点邻域内的像素梯度信息完成了特征描述字的构造。SAR图像实测数据验证表明,与其他尺度不变特征提取算法相比,本文算法具有更优的稳定性。 相似文献
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基于Co-motion的可见光——热红外图像序列自动配准算法 总被引:5,自引:5,他引:0
提出了一种基于Co-motion的可见光--热红外图像序列自动配准方法, 引入Co-motion运动统计特征来解决异源图像序列配准问题, 从而避开了异源图像相似图像特征提取和精确运动检测的难题. 由于可见光和热红外成像机理不同, 在运用运动统计特征时, 会面临与同源配准不同的诸多问题, 如难以提取相似前景、大量外点干扰和易受大尺度变化的影响等. 本文通过对所面临难题的分析 提出了适合于异源图像序列配准的同名点对选取方法和外点去除方法, 并精确迭代优化变换模型. 对俄亥俄州大学红外--可见光数据库和自建数据库共8组数据的实验分析结果表明, 该算法在大尺度、旋转、平移及视场角变化下均能精确配准. 相似文献
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为了实现高分辨率SAR 影像与光学影像之间自动/半自动配准, 提出了一种新颖、稳健的匹配算法。算法首先利用仿射变换进行SAR 影像和光学影像粗匹配, 简化了整体算法的处理复杂度;然后利用影像边缘稳健性, 使用边缘提取算子分别对SAR 影像和光学影像进行边缘提取, 为后续精匹配做好了数据准备; 最后使用基于边缘纹理跨接约束进行影像之间精匹配, 方法引入了邻域配准约束机制, 很好的解决了经典匹配多峰值效应, 提高了算法稳健性和实用性。以国内机载高分辨率SAR 数据和SPOT 25 PAN 数据为例进行算法验证, 实验结果表明该算法能实现自动/半自动的高分辨率SAR 和光学影像之间的像素级配准。 相似文献
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The SIFT operator's success for computer vision applications makes it an attractive alternative to the intricate feature based SAR image registration problem. The SIFT operator processing chain is capable of detecting and matching scale and affine invariant features. For SAR images, the operator is expected to detect stable features at lower scales where speckle influence diminishes. To adapt the operator performance to SAR images we analyse the impact of image filtering and of skipping features detected at the highest scales. We present our analysis based on multisensor, multitemporal and different viewpoint SAR images. The operator shows potential to become a robust alternative for point feature based registration of SAR images as subpixel registration consistency was achieved for most of the tested datasets. Our findings indicate that operator performance in terms of repeatability and matching capability is affected by an increase in acquisition differences within the imagery. We also show that the proposed adaptations result in a significant speed-up compared to the original SIFT operator. 相似文献
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一种基于结构特征边缘的多传感器图像配准方法 总被引:11,自引:1,他引:10
图像配准是多传感器图像融合等处理的前提. 本文以包含人造目标的合成孔径雷达(Synthetic aperture radar, SAR)图像和可见光图像为处理对象, 提出了一种基于结构特征边缘的多传感器图像配准方法. 该方法提取人造目标在两类图像中表现的共性特征---结构特征边缘, 并基于边缘匹配构造虚拟角点, 采用基于特征一致的粗配准方法和基于虚拟角点的精配准方法, 对待配准图像实现由粗到精的自动配准. 实验结果表明, 本文方法能够取得较高的配准精度. 相似文献
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由于SAR和可见光成象传感器图象的物理特征不同,因此进行匹配难度很大。本文在深入分析了这两种传感器图象物理特征的基础上,提出了一种图象匹配的新方法。该方法运用形态学滤波方法去除SAR图象斑点噪声,利用图象的边缘特征进行匹配,并采用多分辨率分级搜索技术减少计算量,在对实验结果进行分析的基础上提出了搜索真实匹配位置的原则,大大提高了匹配的准确率。通过实验对SAR图象斑点噪声滤波和SAR与可见光图象匹配算法进行了验证,实验证明本算法的SAR图象去噪效果明显优于传统的Frost方法,图象匹配精度高,稳定性好。 相似文献
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Z. She D. A. Gray R. E. Bogner J. Homer I. D. Longstaff 《International journal of remote sensing》2013,34(20):4357-4382
Three-dimensional (3D) synthetic aperture radar (SAR) imaging via multiple-pass processing is an extension of interferometric SAR imaging. It exploits more than two flight passes to achieve a desired resolution in elevation. In this paper, a novel approach is developed to reconstruct a 3D space-borne SAR image with multiple-pass processing. It involves image registration, phase correction and elevational imaging. An image model matching is developed for multiple image registration, an eigenvector method is proposed for the phase correction and the elevational imaging is conducted using a Fourier transform or a super-resolution method for enhancement of elevational resolution. 3D SAR images are obtained by processing simulated data and real data from the first European Remote Sensing satellite (ERS-1) with the proposed approaches. 相似文献
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Although optical image registration methods have been successfully developed over the past decades, the registration of optical and synthetic aperture radar (SAR) images is still a challenging problem in remote sensing. Feature-based methods are considered to be more effective for multi-source image registration. However, almost all of these methods rely on the feature extraction algorithms. In this article, a simultaneous segmentation and feature-based registration method based on an iterative level set and scale-invariant feature transform (ILS-SIFT) is proposed. The core idea consists of three aspects: (1) an iterative procedure that combines image segmentation and matching is proposed to avoid registration failure caused by poor feature extraction; (2) a uniform level set segmentation model for optical and SAR images is presented to segment conjugate features; and (3) an improved SIFT algorithm is employed to determine whether the registration was successful. Experimental results have shown the effectiveness and universality of the proposed method. 相似文献
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描述了一种基于Hausdorff 度量的合成孔径雷达和光学图像配准方法。首先用基于低帽滤波的方法提取待配准图像的闭合轮廓。然后对较长的轮廓进行Hausdorff 度量初匹配, 并对初匹配的结果使用轮廓中心的相对距离比直方图聚束检测法进行一致性检测。最后, 在得到正确的闭合轮廓对后, 使用最小二乘法计算图像的变换参数。考虑到雷达图像的相干斑噪声以及多传感器图像成像时间造成的变形, 多传感器图像提取的轮廓会有一定的差别。而Hausdorff 度量对误差有很好的容忍性, 因此本方法可以对多传感器图像进行配准。 相似文献
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On 6 September 2008, two optical satellites, HJ-1 A and B (HJ-1 A/B), were successfully launched from China. However, the system geometric correction products of the HJ-1 A/B charge-coupled device (HJ-1 images) have low geometric precision and need to be corrected. The HJ-1 images have a large aspect angle, a wide swath width, and a large image size. Furthermore, the local geometric distortions are too complex in one scene. Given these characteristics of HJ-1 images, geometric correction is still a challenging work. This article proposes an automatic geometric precision correction system (GPCS) based on the automatic registration between HJ-1 images and Landsat Thematic Mapper images. First, the coarse image matching method based on geometric-restricted scale-invariant feature transform (SIFT) is used to determine the coarse global transformation between the HJ-1 image and the reference image. Second, inspired by the hierarchical method of non-rigid registration for medical images, a hierarchical image matching approach is proposed based on the combination of SIFT feature points and template matching. This approach decomposes a matching problem of a whole image into numerous matching problems of image blocks and can overcome the impact of local distortions in HJ-1 images. Hierarchical random sample consensus (RANSAC) based on digital elevation model (H-RANSAC) is used to remove incorrect control points. Third, an HJ-1 image is rectified using a triangulated irregular network. Finally, the automatic evaluation method based on automatic image matching between the corrected HJ-1 image and the reference image is adopted to evaluate the geometric precision. On the one hand, experiments on eight HJ-1 images demonstrate the efficiency and accuracy of the different steps of GPCS. On the other hand, experiments on 1000 HJ-1 images also demonstrated the robustness, accuracy, and suitability for batch processing. 相似文献
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SAR图像配准是SAR图像应用,尤其是时间序列SAR图像应用的重要处理步骤之一。为实现重复星载SAR图像的快速、自动配准,通过将小波多尺度变换与快速傅立叶频谱变换相结合,实现了对星载SAR图像间初始偏移的快速估计,并在此基础上利用基于窗口的相关分析,实现了SAR图像的精确配准。选用星载ALOS-PALSAR和Radarsat-2影像作为试验数据,对提出的方法进行了实验分析。实验结果表明:该方法在无需任何先验知识的情况下,可以全自动完成重复轨道星载SAR数据的快速配准,且精度满足SAR干涉处理等时间序列SAR应用处理的需求,具有较强的鲁棒性。 相似文献