Drăguţ Lucian, Eisank Clemens
Department of Geography and Geology, University of Salzburg, Hellbrunnerstraße 34, Salzburg 5020, Austria.
Geomorphology (Amst). 2012 Mar 1;141-142(4):21-33. doi: 10.1016/j.geomorph.2011.12.001.
We introduce an object-based method to automatically classify topography from SRTM data. The new method relies on the concept of decomposing land-surface complexity into more homogeneous domains. An elevation layer is automatically segmented and classified at three scale levels that represent domains of complexity by using self-adaptive, data-driven techniques. For each domain, scales in the data are detected with the help of local variance and segmentation is performed at these appropriate scales. Objects resulting from segmentation are partitioned into sub-domains based on thresholds given by the mean values of elevation and standard deviation of elevation respectively. Results resemble reasonably patterns of existing global and regional classifications, displaying a level of detail close to manually drawn maps. Statistical evaluation indicates that most of classes satisfy the regionalization requirements of maximizing internal homogeneity while minimizing external homogeneity. Most objects have boundaries matching natural discontinuities at regional level. The method is simple and fully automated. The input data consist of only one layer, which does not need any pre-processing. Both segmentation and classification rely on only two parameters: elevation and standard deviation of elevation. The methodology is implemented as a customized process for the eCognition® software, available as online download. The results are embedded in a web application with functionalities of visualization and download.
我们引入了一种基于对象的方法,用于从航天飞机雷达地形测绘任务(SRTM)数据中自动分类地形。新方法依赖于将地表复杂性分解为更均匀区域的概念。通过使用自适应、数据驱动技术,在三个代表复杂性区域的尺度级别上自动分割和分类高程层。对于每个区域,借助局部方差检测数据中的尺度,并在这些适当的尺度上进行分割。分割产生的对象分别根据高程平均值和高程标准差给出的阈值划分为子区域。结果与现有的全球和区域分类模式合理相似,显示出接近手工绘制地图的细节程度。统计评估表明,大多数类别满足区域化要求,即最大化内部同质性,同时最小化外部同质性。大多数对象的边界与区域层面的自然间断相匹配。该方法简单且完全自动化。输入数据仅由一层组成,无需任何预处理。分割和分类仅依赖于两个参数:高程和高程标准差。该方法作为eCognition®软件的定制过程实现,可在线下载。结果嵌入到具有可视化和下载功能的网络应用程序中。