共查询到20条相似文献，搜索用时 31 毫秒
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从冗余数据中选择一个或者多个最为显著的立体像对,在最少“伪信息”的影响下,获取最佳影像匹配效果,降低其它质量较差影像的负面平均效应,是提高多视影像匹配性能的关键。基于准确匹配的特征点,通过匹配测度的鲁棒性分析,提出一种多视影像的匹配质量分析方法;在此基础上,提出了一种基于特征点引导的多视影像择优匹配方法及基本思想、计算基础和择优匹配步骤。利用ADS40多度重叠影像数据进行了择优匹配实验。结果表明,该方法能够有效选取匹配质量较优的影像,获取更加准确的多视匹配结果,在一定程度上,比传统的多视匹配方法更加有效。 相似文献
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提出了一种基于卡尔曼运动模型进行运动模糊图像退化过程分析的方法 ,设计了基于卡尔曼运动质量退化模型的运动模糊图像恢复算法 ,该方法逼近实际的运动模型。通过对火车称重系统中的模糊影像恢复实验 ,表明了该恢复技术的有效性 相似文献
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Image aliasing is a problem appearing as artefacts in digitally resampled images, which degrades the quality of the image. In digital rectification and texture mapping, pixels from an input image are transformed to pixels of an output image. The discrete nature of a digital image causes aliasing in the transformed image. In this paper the source of aliasing and the theory of antialiasing are described. The necessity of a precise filter design in antialiasing is discussed and a filter based on a Kaiser adjustable window is designed. Different practical antialiasing methods are described as well as interpolation methods, which are conventional in photogrammetry. Selected antialiasing methods are implemented and applied to a close range image. An objective analysis is carried out by applying inverse transformations to rectified images and deriving some measures to estimate the information loss for each method by comparing original and reconstructed images. Results indicate that interpolation methods are not capable of removing or reducing aliasing in highly decimating transformations. The output images of interpolation methods therefore suffer from edge corruption and interfusion of small features. Applying a Kaiser filter with a precise antialiasing method results in the least information loss and considerably reduces aliasing at the expense of higher computation load. 相似文献
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Spatial database updating using active contours for multispectral images: application with Landsat 7
S. Jodouin L. Bentabet D. Ziou J. Vaillancourt C. Armenakis 《ISPRS Journal of Photogrammetry and Remote Sensing》2003,57(5-6):346
This paper presents a fully automated approach for area detection and delineation based on multispectral images and features from a topographic database. The vectors residing in the database are refined using active contours (snakes) according to updated information provided by the multispectral images. The conventional methods of defining the external energy guiding the deformation of the snake based on: (1) statistical measures; or (2) gradient-based boundary finding is often corrupted by poor image quality. Here a method to integrate the two approaches is proposed using an estimation of the maximum a posteriori (MAP) segmentation in an effort to form a unified approach that is robust to noise and poor edges. We further propose to improve the accuracy of the resulting boundary location and update of the snake topology. A number of experiments are performed on both synthetic and LANDSAT 7 images to evaluate the approach. 相似文献
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BAI Di FAN Qibin SHU Qian 《地球空间信息科学学报》2005,8(3):171-175
Taking the advantage of the lifting scheme＇s characters that can build wavelet translorms tor transforming from integer to integer and the quality of the reconstructing image＇is independent of the topology way adopted by the boundary, an image fusion algorithm based on lifting scheme is proposed. This paper discusses the fundamental theory of lifting scheme firstly and then after taking transform analysis according to a kind of images that need to be confused. 相似文献
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This paper is an exploratory study, which aimed to discover the synergies of data fusion and image segmentation in the context of EO-based rapid mapping workflows. Our approach pillared on the geographic object-based image analysis (GEOBIA) focusing on multiscale, internally-displaced persons’ (IDP) camp information extraction from very high spatial resolution (VHSR) images. We applied twelve pansharpening algorithms to two subsets of a GeoEye-1 image scene that was taken over a former war-induced ephemeral settlement in Sri Lanka. A multidimensional assessment was employed to benchmark pansharpening algorithms with respect to their spectral and spatial fidelity. The multiresolution segmentation (MRS) algorithm of the eCognition Developer software served as the key algorithm in the segmentation process. The first study site was used for comparing segmentation results produced from the twelve fused products at a series of scale, shape, and compactness settings of the MRS algorithm. The segmentation quality and optimum parameter settings of the MRS algorithm were estimated by using empirical discrepancy measures. Non-parametric statistical tests were used to compare the quality of image object candidates, which were derived from the twelve pansharpened products. A wall-to-wall classification was performed based on a support vector machine (SVM) classifier to classify image objects candidates of the fused images. The second site simulated a more realistic crisis information extraction scenario where the domain expertise is crucial in segmentation and classification. We compared segmentation and classification results of the original images (non-fused) and twelve fused images to understand the efficacy of data fusion. We have shown that the GEOBIA has the ability to create meaningful image objects during the segmentation process by compensating the fused image’s spectral distortions with the high-frequency information content that has been injected during fusion. Our findings further questioned the necessity of the data fusion step in rapid mapping context. Bypassing time-intensive data fusion helps to actuate EO-based rapid mapping workflows. We, however, emphasize the fact that data fusion is not limited to VHSR image data but expands over many different combinations of multi-date, multi-sensor EO-data. Thus, further research is needed to understand the synergies of data fusion and image segmentation with respect to multi-date, multi-sensor fusion scenarios and extrapolate our findings to other remote sensing application domains beyond EO-based crisis information retrieval. 相似文献
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Binu Balakrishnan S. H. Darsana Jayamol Mathews Madhu S. Nair 《Journal of the Indian Society of Remote Sensing》2018,46(11):1761-1771
Satellite/aerial images taken from high altitude contain large amount of pixels to store accurate information. These high resolution images require large storage capacity and more transmission time. Applying an efficient compression technique on these images can reduce high storage capacity requirement and transmission time. In this paper block truncation coding (BTC) based color image compression technique for aerial/satellite images is proposed. High degree of correlation among the RGB planes of a color image can be reduced by converting these planes into HSV planes. Each of the H and S planes are encoded using BTC with quad clustering and V plane is encoded with BTC based bi-clustering or tri-clustering depending on the edge information present in the plane. The effectivity of the proposed method is validated by comparing it with the conventional BTC and its variant methods. Experimental analysis indicate that the proposed method is superior to other state of the art methods both in terms of visual quality and quantitative metrics. 相似文献
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介绍了日本ALOS卫星PRISM三线阵传感器的成像原理和方法,提出了利用PRISM三线阵影像进行超分辨率重建来提高PRISM影像的空间分辨率.提出了新的光流配准算法,该算法将标准互相关配准算法引入到Lueas-Kanade光流配准算法中,大大的减少了误配率,能够有效的消除PRISM Level 1级别的影像之间由于地形起伏所引起的变形.同时,改进了影像的高斯退化模型,在超分辨率算法中,引入了可变退化函数,通过交替最小化(AM)算法对可变退化函数进行盲估计,实验结果表明,超分辨率重建影像与插值影像相比,细节清晰很多,有效的提高了影像的分辨率.实验结果说明了本文配准算法可以达到超分辨率重建的亚像素的精度要求,可以应用于航空遥感影像的高精度匹配,同时也说明了将航空遥感影像的退化函数算子分为高斯退化算子和可变退化算子的思想是正确的,符合实际情况. 相似文献
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图像融合的目的是把同一目标的多幅图像融合成一幅质量高的图像。本文给出了一种基于小波变换的图像融合方法,首先对大比例尺土地利用图像使用正交小波进行分解,再使用小比例尺土地利用图像替换分解出的低频近似信息,然后重构,得到两幅土地利用图像的融合图像。最后使用该方法对两幅土地利用图像进行了融合,得到的融合后的土地利用图像汲取了两幅图像的优势,在一定程度上实现了土地利用空间类型的信息量随比例尺变化而自动增减。 相似文献
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提出了一种建立在数据颗粒引力基础上的图像分类方法,此方法使用的数据颗粒质量是图像的特征（如图像的分形维）。对于每一类别训练数据颗粒集,图像特征采用训练数据颗粒集中几幅图像特征的均值mi,用训练数据颗粒集的像幅数wi作为它的权重,那么第i个训练数据颗粒集的质量为wi mi,而待检验数据颗粒是原子数据颗粒,其质量为1。假定待检验一幅图像数据颗粒j的特征为tmj,那么第i个训练数据颗粒集与待检验一幅图像的数据颗粒j之间的距离为|mi-tmj|。假定有3种不同类别的图像,从各类别中取出一部分图像组成3类训练数据颗粒集,求得每类数据颗粒集特征的均值和一幅待检验数据颗粒的特征值,按公式计算每类数据颗粒集对待检验数据颗粒的引力,3个引力中具有最大引力的类别即为待检验数据颗粒的类别。实验结果表明,基于数据引力的图像分类方法具有一定的优势。 相似文献
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目前,遥感影像应用的场景越来越多,但受到空气污染或气候等原因影响,局部地区雾霾现象严重,严重影响遥感影像质量。针对这一问题,本文结合遥感影像的特点提出了一种基于暗原色先验的遥感影像去雾方法。首先,结合遥感影像的特点,在求取暗通道过程中设置失效点,排除不符合暗原色先验的像素点;其次,根据获得的暗通道计算大气光值;然后,求取透射率图并用导向滤波精细化,根据大气传输模型求得去雾后的影像;最后,分别用无人机影像和Landsat卫星遥感影像进行去雾实验,验证了本文方法的有效性。 相似文献
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In this paper, a novel approach based on multiobjective particle swarm optimization (MOPSO) is presented for panchromatic (Pan) sharpening of a multispectral (MS) image. This new method could transfer spatial details of the pan image into a high-resolution version of the MS image, while color information from the low-resolution MS image is well preserved. The pan and MS images are locally different because of different resolutions, and therefore we cannot directly combine them in the spatial domain. For this reason, we generate two initial results, which are more appropriate for a weighted combination. First, the pan and the MS images are histogram matched. Then we use the shiftable contourlet transform (SCT) to decompose the histogram-matched pan and MS images. The SCT is a new shiftable and modified version of the contourlet transform. In this step, an algorithm based on the SCT is used to generate two initial results of the high-resolution MS images. Our objective is to produce two modified high-resolution MS images, in which one has high spatial similarity to the pan image and the other one has high radiometric quality in each band. Therefore, we have used two different fusion rules to integrate the high-frequency contourlet coefficients of the pan and MS images to generate two initial results of high-resolution MS image or the pan-sharpened (PS) image. Finally, we can find the optimal PS image by applying the MOPSO algorithm and using the two initial PS results. Specifically, the PS image is obtained via a weighted combination of the two initial results, in which the weights are locally estimated via a multiobjective particle swarm optimization algorithm to generate a PS image with high spatial and radiometric qualities. Based on experimental results obtained, the produced pan-sharpened image also has good spectral quality. The efficiency of the proposed method is tested by performing pan-sharpening of high-resolution (Quickbird and Wordview2) and medium-resolution (Landsat-7 ETM +) datasets. Extensive comparisons with the state-of-the-art pan-sharpening algorithms indicate that our new method provides improved subjective and objective results. 相似文献
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Sofou A. Evangelopoulos G. Maragos P. 《Geoscience and Remote Sensing Letters, IEEE》2005,2(4):394-398
Automated processing of digitized soilsection images reveals elements of soil structure and draws primary estimates of bioecological importance, like ground fertility and changes in terrestrial ecosystems. We examine a sophisticated integration of some modern methods from computer vision for image feature extraction, texture analysis, and segmentation into homogeneous regions, relevant to soil micromorphology. First, we propose the use of a morphological partial differential equation-based segmentation scheme based on seeded region-growing and level curve evolution with speed depending on image contrast. Second, we analyze surface texture information by modeling image variations as local modulation components and using multifrequency filtering and instantaneous nonlinear energy-tracking operators to estimate spatial modulation energy. By separately exploiting contrast and texture information, through multiscale image smoothing, we propose a joint image segmentation method for further interpretation of soil images and feature measurements. Our experimental results in images digitized under different specifications and scales demonstrate the efficacy of our proposed computational methods for soil structure analysis. We also briefly demonstrate their applicability to remote sensing images. 相似文献
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基于经验模态分解的高分辨率影像融合(英文) 总被引：3，自引：0，他引：3
High resolution image fusion is a significant focus in the field of image processing. A new image fusion model is presented based on the characteristic level of empirical mode decomposition （EMD）. The intensity hue saturation （IHS） transform of the multi-spectral image first gives the intensity image. Thereafter, the 2D EMD in terms of row-column extension of the 1D EMD model is used to decompose the detailed scale image and coarse scale image from the high-resolution band image and the intensity image. Finally, a fused intensity image is obtained by reconstruction with high frequency of the high-resolution image and low frequency of the intensity image and IHS inverse transform result in the fused image. After presenting the EMD principle, a multi-scale decomposition and reconstruction algorithm of 2D EMD is defined and a fusion technique scheme is advanced based on EMD. Panchromatic band and multi-spectral band 3,2,1 of Quickbird are used to assess the quality of the fusion algorithm. After selecting the appropriate intrinsic mode function （IMF） for the merger on the basis of EMD analysis on specific row （column） pixel gray value series, the fusion scheme gives a fused image, which is compared with generally used fusion algorithms （wavelet, IHS, Brovey）. The objectives of image fusion include enhancing the visibility of the image and improving the spatial resolution and the spectral information of the original images. To assess quality of an image after fusion, information entropy and standard deviation are applied to assess spatial details of the fused images and correlation coefficient, bias index and warping degree for measuring distortion between the original image and fused image in terms of spectral information. For the proposed fusion algorithm, better results are obtained when EMD algorithm is used to perform the fusion experience. 相似文献
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小波超分辨率重建算法及其在SPOT影像中的应用 总被引：1，自引：0，他引：1
影像超分辨率重建就是从一系列质量较差、分辨率较低的图像来重建图像质量更好、空间分辨率更高的影像的算法.在将所有低分辨率影像纳入同一参考格网中考虑的情况下,低分辨率数据相当于一非规则采样的交错采样数据.本文在多分辨率分析的基础上对基于小波的影像超分辨率重建理论进行介绍,并将现有的小波超分辨率重建算法推广到更一般的运动模型,以充分利用交错采样数据的内在规律性和结构特征,同时针对SPOT影像的特点,分析SPOT影像的调制传送函数,对SPOT重建影像进行包括去噪与解卷积的复原后处理.最后给出基于小波的SPOT影像超分辨率重建结果,表明遥感影像的超分辨率重建在应用中取得进展. 相似文献