地图模式识别研究的介绍与展望

地图模式识别是近年来在地图制图领域中新兴起来的一门高新技术，是信息时代人工智能、模式识别技术在地图制图中的具体应用，本文对我们在地图模式识别研究领域的进展分五个问题进行了概述。最后对地图模式识别今后的发展进行了展望。     

地图制图中的地图模式识别

地图模式识别是地图学科的一个重要研究方向。本文在阐明地力模式识别基本概念的基础上，重点探讨了地图模式识别的几个主要过程，以及常用的几种识别方法。并简要地介绍了课题研究的进展情况。     

顾及密度差异的河系简化

河系简化是地图综合中经常需要处理的任务,其难点主要在于依据上下文环境对河流进行结构化选取,以保持河网密度差异等宏观特征。提出一种新的河流等级规则,依据河流的各级支流的数量确定河流的等级,以反映河流的密度差异;设计一种结合河流等级、长度与所在层次的综合指标进行河流选取;探讨在自动构建河系树的基础上计算河流等级、所在层次等指标的方法;最后使用综合指标进行河流结构化选取试验。结果表明,以新等级规则为基础的综合指标切实可行,能够在一定程度上保持河网密度的区域差异。     

建筑物的渐进式图形简化方法

以建筑物轮廓图形的直线段为基本图形单元,研究了建筑物图形渐进式综合的算法以及综合过程中的控制策略和数据预处理方法,并实现了该算法.     

以直角方式转折的面状要素图形简化方法

讨论了面状要素图形轮廓简化的一些规则以及面的空间知识获取方法,结合以直角方式转 折的面状要素图形轮廓的特点,重点讨论了其图形渐进式简化方法。     

地图模式识别中的矢量化技术

扫描数字化是ＧＩＳ中快速获取地理数据的手段之一,其关键是对扫描图上的地图要素进行自动识别,本文针对地图模式识别中的矢量化技术进行了研究,利用预测跟踪和轮廓跟踪方法对道路,居民地等要素进行了矢量化,并给出了矢量数据的压缩方法。     

高等线的空间关系规则和渐进式图形简化方法

详细讨论了等离线表达地形的规划和以此为基础自动建立等高线关系的方法,对地形特征点、线的提取改进了已有较成熟的方法,建立了一套实用的高等线图形简化的渐进式方法,并对其特殊情况的处理提出了具体的算法。这种方法把不同比例尺跨度的等高线图形综合融为一体,易于实现,等高线图形简化时的等高线相交可在综合过程中控制。     

地图模式识别的发展现状

地图模式识别是由计算机来对地图进行识别与理解，并借助一定的技术手段研究和分析地图上的各种模式信息，获取地图要素的信息，其在似于人对地图的阅读，它是近年来在地图制图领域中新兴起来的一门高技术，是信息时代人工智能、模式识别技术在地图制图中的具体应用。由于它是传统地图制图迈向数字地图制图的一座桥梁，因此，地图模式识别代表了当前地图制图领域发展的前沿和主攻方向，它与遥感技术、地理信息系统一起，被称为现代地图制图的三大技术。     

模式识别及其在地图制图中的发展现状分析

模式识别在地图制图中的应用，是实现地图制图自动化的重要研究内容。通过对模式识别，地图制衅，以及地图模式识别的发展回顾和现状分析，阐述了开展地图模式识别研究的重要意义，并指出了其研究重点。     

The Spatial Characteristics of a Line and Their Application to Line Simplification

This paper discusses the spatial knowledge related to a line,and the characteristic points of lines is detected.According to the requirements of line generalization,new algorithms for identifying characteristic line points are presented.These characteristic points are used to improve the algorithms of line generalization.An algorithm for identifying bends is shown.In this paper,improved algorithms based on those by Douglas-Peucker,Visvalingam and Whyatt are shown.In this test,the progressive process of line generalization is emphasized.     

The method of graphic simplification of area feature boundary with right angles

Some rules of simplification of area feature boundary and the method of acquiring spatial knowledge, such as maintaining area and shape of area feature, are discussed. This paper focuses on the progressive method of graphic simplification of area feature boundary with right angles based on its characteristics.     

The method of graphic simplification of area feature boundary with right angles

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Schematic road network map progressive generalization based on multiple constraints

Multiple constraints for schematic road network map cartographic design are analyzed and summarized. Based on this, a set of quantitative criteria are set up and a new road network generalization method including progressive selection and displacement is proposed. Furthermore, topological checking methods for road networks are researched. Based on these constraints, the points in a road network are classified, and a satisfactory and effective schematic map is designed in a concrete experiment while maintaining topological consistency of the road network between the original and the schematic map.     

多约束条件下示意性道路网地图渐进式综合

Multiple constraints for schematic road network map cartographic design are analyzed and summarized. Based on this, a set of quantitative criteria are set up and a new road network generalization method including progressive selection and displacement is proposed. Furthermore, topological checking methods for road networks are researched. Based on these constraints, the points in a road network are classified, and a satisfactory and effective schematic map is designed in a con- crete experiment while maintaining topological consistency of the road network between the original and the schematic map     

建筑物多边形化简及优化的自动方案研究

针对居民地地图形状化简的一个方面——建筑物多边形的化简,通过对综合规则的研究和居民地几何特征的剖析,提出一种与比例尺相关的切割实现建筑物多边形化简的方法,在Visual Basic6.0环境下实现了该算法,试验结果表明此方法在保持街区的形态特征上效果较好。     

Recognizing building groups for generalization: a comparative study

Recognition of building groups is a critical step in building generalization. To find building groups, various approaches have been developed based on the principles of grouping (or the Gestalt laws of grouping), and the effectiveness of these approaches needs to be evaluated. This study presents a comparative analysis of nine typical such approaches, including three approaches that only consider proximity principle and six approaches that consider multiple grouping principles. Real-life dataset at 1:5000, 1:10,000, and 1:50,000 scales provided by National Geomatics Center of China is used to evaluate the performance of these approaches. Buildings at smaller scales are used to construct the benchmarks to test the grouping results at larger scales, and the adjusted Rand index is adopted to indicate the accuracy of the detected groups. Significant tests (Friedman test and Wilcoxon signed-rank test) are also performed to provide both the overall and pairwise comparisons of these approaches. The results show that (1) the average accuracy of most existing approaches is between 0.3 and 0.5, and the performances of these approaches are significantly different; (2) when only proximity is considered, the buffer analysis approach performs significantly better than other approaches; (3) when multiple grouping principles are considered, the local constraint-based approach usually performs better than other approaches; (4) existing approaches that consider similarity and/or continuity seldom improve the performance of building grouping.     

Progressive graphic simplification of contours based on spatial reasoning

This paper discusses the rules representing relief with contour lines and methods for automatically constructing relation of contour lines. Mean-while, the improvement of existent methods for extracting the topographic characteristic points and lines is described. On the basis of this analysis, we propose a series of practicable progressive graphic simplification ideas of contour lines and concrete algorithms for the exception’s handling. In this way, graphic generalizations of contour lines at different scales are integrated into one model that is convenient to implement, and in which contour lines’ intersection in generalization can be controlled.     

Progressive graphic simplification of contours based on spatial reasoning

This paper discusses the rules representing relief with contour lines and methods for automatically constructing relation of contour lines.Meanwhile,the improvement of existent methods for extracting the topographic characteristic points and lines is described.On the basis of this analysis,we propose a series of practicable progressive graphic simplification ideas of contour lines and concrete algorithms for the exception's handling.In this way,graphic generalizations of contour lines at different scales are integrated into one model that is convenient to implement,and in which contour lines' intersection in generalization can be controlled.     

基于最小二乘的建筑物多边形的化简与直角化

已有的建筑物化简方法大多侧重于化简原则中的某一方面,且对制图专家已有的化简共识考虑不足。通过模仿制图专家建筑物化简的思维过程和操作流程,提出一种利用“计算区”（与某组小于阈值的边化简有关的节点序列称为该组边的计算区）进行建筑物短边结构识别与渐进式化简的方法。首先对建筑物轮廓进行预处理和垂直增强;然后对其分组,并利用“计算区”对小于阈值的边进行结构识别、分析,确定最优化简方案;最后通过整体调整,在形状保持的前提下减小面积差。以众源开放街道地图（OpenStreetMap,OSM）建筑物数据为例,将所提方法与ArcGIS建筑物化简工具化简的结果进行对比分析,实验结果表明,所提方法有效减少了图形节点数,增强了平行、直角等形状特征,并减小了化简前后面积差,较好兼顾并平衡了建筑物化简原则的几个方面,为建筑物化简提供了新思路。