共查询到20条相似文献,搜索用时 187 毫秒
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为了有效地进行高分辨率SAR图像中道路目标的提取,提出了一种基于平行线对检测的主干道提取算法。处理过程分为三个层次,在低层次处理中,在经过增强Frost滤波预处理之后,采用指数加权平均比率算子对图像进行边缘检测,得到边缘像素;中层处理则先消除短线段,进行初始的路段连接,再利用平行线对检测算法,检测可能的道路段。而后在高层次处理中,进行路段的最终连接并根据建立的道路的数学模型进行道路的识别,最后通过生长判断器进行行道树干扰下路段的生长。在多幅SAR图像上进行的实验证明了该算法的有效性。 相似文献
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基于对象的遥感影像道路提取 总被引:1,自引:0,他引:1
根据高分辨率遥感影像道路网络的特点,提出一种基于对象的道路提取算法.首先根据道路的局部光谱特性和几何特性,使用图像分割和边缘提取算法对图像进行预处理.然后,根据贝叶斯理论,基于道路的全局几何特性和拓扑特性,建立网络的数学模型,将网络提取问题转化为全局优化问题,使用可逆跳跃马尔可夫链蒙特卡罗算法求取全局最优网络.实验结果表明,该方法充分利用了道路的各种特性,可以有效地从遥感图像中提取出道路,具有较高的精度和实用性. 相似文献
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提出一种改进区域生长法的遥感影像中道路提取方法。对遥感影像进行[K]均值聚类,实现道路区域和非道路区域的初步分离,并获取区域生长的基准值,按照图像特征计算出区域生长的阈值。依据对道路特性的分析,设计了9个道路路口模型。根据设计的道路路口模型,对区域生长法进行了改进,使得道路的提取按照道路路口模型自动增长。最后通过数学形态学的手段对道路进行优化。实验结果表明使用提出方法所提取道路区域更加完整。 相似文献
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基于Hough变换的高分辨率遥感影像城市直线道路提取 总被引:2,自引:0,他引:2
根据高分辨率遥感影像城市直线道路特性,提出在图像分割获得道路网轮廓的基础上,使用Hough变换检测道路所在直线,对直线进行道路判断,再将所得道路段进行修剪、连接形成道路网,实现道路提取。实验结果表明,该方法能有效的从高分辨遥感影像中提取城市直线道路。 相似文献
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彩色地图中道路的识别和提取 总被引:1,自引:0,他引:1
对彩色地图中道路信息的识别与提取方法进行了研究,根据道路自身的特征,提出了一种利用圆形度与颜色特征相结合的提取方法,同时,对若干相关问题进行了详细的介绍,如区域标记、圆形度等.还介绍了对道路信息提取之后的细父化和矢量化,并着重描述了道路细化过程中形态变换的用法.通过研究可以得出,利用这种提取方法可以使处理的结果更准确,而且在提取的过程中可以很自然的把道路上的文字等噪声去掉. 相似文献
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从航空遥感图像中自动提取主要道路 总被引:37,自引:2,他引:35
如果能自动地从航空遥感图像中提取出道路网,将会简化城市地物目标的分类和测量过程.该文根据城市主要道路在图像中的特性进行了模型化处理,进而提出了基于直线的、自动提取的方法.算法重点考虑到成像过程中必然引入的各种噪声,用高斯分布函数模糊化直线参数,使提取具有良好的稳健性.算法中的参数选择都是通过理论分析所得,因此,提取过程实现了自动化.实验结果表明,该方法能够从实际航空遥感图像中提取出主要道路网. 相似文献
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针对传统的卷积神经网络在复杂道路场景中无法有效地提取车道特征的问题,论文提出了一种基于传感器融合和方向可调卷积神经网络的车道检测算法.该算法首先利用激光雷达对道路场景下的道路表面激光点进行提取,然后将提取的道路点投影到图像坐标,之后将融合道路表面空间信息的二维图像作为网络输入.在提取车道特征过程中,方向可调卷积神经网络只对处于道路表面内的特征进行提取,避免了道路表面障碍物和道路旁的公共设施的干扰,实现车道线的精准检测.实验结果表明,该方法在复杂道路场景下的车道识别率可达到92.21%. 相似文献
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Free access to global data sets of satellite images and digital elevation models (DEMs) such as Aster Global DEM (GDEM) and Shuttle Radar Topography Mission (SRTM) digital topography are expected to contribute to various study areas that deal with land cover and land use. To assess the capabilities of these global DEM data sets and to provide guidelines for performing shade removal under various terrain and illumination conditions, we evaluated the results of shade removal using the Minnaert correction and C-correction. These corrections were applied, using the GDEM (versions 1 and 2), SRTM, and a DEM derived from a local map (local DEM), to 30 sample images from 20 scenes of 10 path-rows in global land survey (GLS) Landsat-TM/ETM+ images, in terms of statistical indices and the accuracy of land-cover discrimination. The analysis indicated that the results of shade removal depended mainly on the correlation between the cosine of the sunshine incidence angle (cos(i)) and the radiance before shade removal, except in some cases with inferior illumination conditions. Of the three global DEMs, GDEM version 2 had the highest performance in shade removal. However, this study also indicated that successful shade removal was only one of the several factors that increased the accuracy of land-cover classification. In practical applications, shade removal can be recommended only for images where the terrain shade obviously disturbs the original spectral reflection characteristics of each land-cover type and no significant dependence of the land-cover distribution on the slope aspect is assumed. In such cases, also global DEMs evaluated in this study can be used for shade removal. 相似文献
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柯泽 《数码设计:surface》2014,(7):77-78
太极湖新区建设是完善武当山旅游服务功能的重大举措,通过林相改造,形成绿树成荫、繁花似锦的自然环境,对建设宜游、宜居、宜养生的国际级生态文化旅游度假区具有重要意义。 相似文献
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The heavy concentration of population, economic activities and high-rise buildings have formed a unique and complex urban morphology in the city centre areas of many metropolitan regions. This research exploits high-resolution LIDAR data to quantify three-dimensional urban morphology and its impacts on the spatio-temporal variability of solar radiation in downtown Houston, Texas. Various urban landscape components, including buildings, trees, shrubs and lawns, have been extracted by combining LIDAR data and colour infrared aerial photographs. An efficient solar flux model is re-implemented as an ArcGIS module with extended capabilities. Monthly and seasonal solar radiation fields are computed in terms of radiation intensity and illumination duration. Our analysis suggests that the extensive and dense distribution of tall and large buildings has dramatically changed the spatial pattern of solar radiation and hence imposed significant impacts on other urban landscape components, especially urban vegetation canopy. We have determined three types of vegetation habitats: shade, semi-sunny/partial shade, and sunny habitats. This research represents the first effort to model spatio-temporal variation of solar radiation in an urban built-up environment using high-resolution LIDAR data. The temporal solar radiation maps would benefit the design and selection of appropriate species of trees, shrubs, flowers and lawn grasses for urban vegetation planting and management. 相似文献
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Forest logging results in decreased and fragmented forest area and the increased appearance of edge habitats. The monitoring of forest area and particularly, the detection of changes over the years relies on correctly determined forest edge locations. Our objective was to characterize the radiance contrast at the sharp forest edges of recently created clearcuts of boreal and boreo‐nemoral forests in Estonia. Radiance data were derived from a medium resolution Landsat Enhanced Thematic Mapper (ETM+) satellite image taken in late winter, in March. In the winter image there is a high radiance contrast at the forest to clearcut boundary area. This radiance contrast was investigated in the visible and near infrared spectral regions (ETM+ bands 1–4) with 30m‐pixel‐size resolution in the spectral bands and 15m‐pixel‐size in the ETM+ panchromatic band. The analyses of radiance contrast at clearcut to forest edges reveal the effects of stand parameters, clearcut age and azimuthal exposure. The results of the analyses show that the radiance contrast between forest and clearcut area depends on the stand height and stem volume of coniferous trees in the first and the second tree layer. The stem volume of deciduous trees had no statistically significant effect on the variation of radiance contrast at the forest edge. A significant non‐linear effect of the edge exposure to sun was found, indicating a shade length effect. Shade and forest structure affect edge detection on medium resolution satellite images. 相似文献
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目的 2维转3维技术可以将现有的丰富2维图像资源快速有效地转为立体图像,但是现有方法只能对树木的整体进行深度估计,所生成的图像无法表现出树木的立体结构。为此,提出一种树木结构层次细化的立体树木图像构建方法。方法 首先利用Lab颜色模型下的像素色差区别将2维树木图像的树干区域和树冠区域分割开来,并对树冠区域进行再分割;然后,在深度梯度假设思想基础上建立多种类型的深度模板,结合深度模板和树冠的区域信息为典型树木对象构建初始深度图,并通过基础深度梯度图组合的方式为非典型树木进行个性化深度构建;最后,根据应用场景对树木深度信息进行自适应调整与优化,将树木图像合成到背景图像中,并构建立体图像。结果 对5组不同的树木图像及背景图像进行了立体树木图像的构建与合成。结果表明,不同形态的树木图像都能生成具有层次感的深度图并自适应地合成到立体背景图像中,构建树木图像深度图的时间与原始树木图像的尺寸成正比,而构建立体树木图像并合成到背景中所需时间在24 s之间。对立体图像质量的主观评价测试中,这些图像的评分均达到良好级别以上,部分立体图像达到了优秀级别。结论 该方法充分利用了树木的形态结构特征,能同时适用于典型和非典型树木,所构建的立体树木图像质量较高,具有丰富的层次感,并具有舒适的立体观看效果。 相似文献
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基于分类及环境特征的树木真实感绘制 总被引:6,自引:0,他引:6
生成高度真实感的虚拟自然场景一直是图形学研究领域中的一个富有挑战性的难题.作为自然场景的重要组成部分,树木的真实感模拟也得到人们的广泛重视.树木种类繁多,形态各异,复杂的结构使其无论在造形、存储还是在绘制上都存在着相当的困难.针对不同的环境特征和不同类型的树木,根据它们的具体特点需采用不同的绘制手段.对于阔叶树,采用基于OpenGL的深度缓存阴影生成算法;对于针叶树,则采用结合光线跟踪和纹元(texel)绘制的技术;而对于距离视点比较远的树,采用的是体纹理映射(volumetrictexturemapping)的方法.实践证明,这几种绘制技术基本上可以满足各种不同类型场景的树木的绘制要求. 相似文献