Contextual Line Simplification (CLS) for ArcGIS

地球表面的地图或可视化表示较小比例尺的地理特征。所以 它所包含的信息必须限制在地图比例尺下以图形方式显示并适合地图的范围内 介质这种调整过程称为泛化。一个基本的泛化过程， 制图是简化，适用于线性要素。线条的简化涉及删除高 密度顶点，基于给定的标准（例如，最小化线失真通过控制的偏移 从原始的广义线;道格拉斯-Peucker算法），以减少复杂性或冗余， 数据集。近年来，随着移动的定位技术的迅速发展，出现了一系列新的应用 (e.g.,车队管理系统，基于位置的服务）已经出现，这产生了大量的 时空（流动性）数据。原始移动性数据通常包括空间-时间位置（三元组：x，y， t）具体对象或抽象概念（例如，传播疾病），形成轨迹来描述 单个物体的运动。为了处理大量的移动数据，通常需要 缩小它的尺寸。轨迹概括（也称为轨迹简化或压缩）已经被实现。 在过去的研究中，提出了一系列解决方案。一种代表性的算法扩展了 Douglas-Peucker算法与同步欧氏距离（SED）的概念。 静态或动态线（轨迹）的简化可能导致违反空间特性的目标线。 源线与空间中其他对象之间的关系（拓扑、方向或距离）。 例如，海船轨迹的概括可以导致与目标轨迹相交的目标轨迹。 岛所提出的方法解决了这个问题，通过引入上下文简化， 将其他图层视为上下文约束的静态和动态线性要素。该方法将 集成到ArcGIS -领先的地理信息系统软件包-工具集，以支持 线性要素的上下文简化，以利于GIS用户群体。

A map or visualization of the earth's surface represents geographic features in a smaller scale. Hence, the information it contains must be restricted to what can graphically be presented at map scale and fit in the map medium. This adjustment process is called generalization. One fundamental generalization process in cartography is simplification, which applies to linear features. Simplification of a line involves removal of high density vertices, based on a given criterion (e.g., minimize line distortion by controlling the offset of the generalized line from the original; Douglas-Peucker algorithm) to reduce complexity or redundancy in a dataset. Lately, with the rapid developments in mobile positioning technologies, a series of new applications (e.g., fleet management systems, location based services) have emerged, which produce vast amounts of spatiotemporal (mobility) data. Raw mobility data typically include the spatio-temporal locations (triplets: x, y, t) of either concrete objects or abstract concepts (e.g., spreading diseases) that form trajectories to describe the movement of individual objects. To handle the massive collections of mobility data there is usually a need to reduce its size. The trajectory generalization (also referred as trajectory simplification or compression) has been considered in the past and a series of solutions have been proposed. A representative algorithm extends the Douglas-Peucker algorithm with the notion of Synchronous Euclidean Distance (SED). The simplification of a static or dynamic line (trajectory) may result in a target line that violates the spatial relations (topological, direction or distance) that apply between the source line and some other objects in space. For example, the generalization of a sea vessel trajectory may result into a target trajectory that intersects an island. The proposed methodology resolves this problem by introducing a contextual simplification of both static and dynamic linear features considering other layers as contextual constraints. This method will be integrated into ArcGIS - the leading Geographic Information System software package - toolset to support a contextual simplification of linear features for the benefit of the GIS user community.