A Microsoft VBA Application for Generating Heat Maps

A choropleth map is a form of thematic map used to portray the structural characteristics of some particular geographical distribution not apparent in data presented in tabular form. Preparation of a choropleth map starts with the assignment of map features to classes based on the value of a specific feature attribute followed by the association of classes of features with appropriate map colors or symbols. Map features are often geographical regions with naturally or artificially defined boundaries, but choropleth maps can also be prepared by segmenting the area to be mapped into a regular grid of regions. Maps prepared with each grid shaded in an intuitive manner such as blue for grids with the lowest attribute values to red for the highest values can be termed “heat maps”. This technical note describes the HeatMap Microsoft Excel application which converts information contained in a worksheet into a heat map, and then converts the heat map into a file suitable for display using mapping systems such as Google Earth. An example illustrates how the application can be used to visualize the seventeenth century frontier between the Polish/Lithuanian Commonwealth and the Ottoman Empire.     

Computer-produced Unclassed Bivariate Choropleth Maps

Many cartographers subscribe to the view that unclassed choropleth maps and multivariate choropleth maps exceed map readers' abilities to process visual information. This paper examines recent evidence which controverts both of these beliefs and discusses applications of a computer program, BICHOR, designed to produce unclassed bivariate choropleth maps interactively on a line plotter or CRT. The maps utilize crossed-line symbolism and putatively overcome both the quantization error inherent in conventionally classed choroplethic displays and the perceptual difficulties associated with color-encoding schemes used for earlier bivariate maps.     

Frequency Histogram Legend in the Choropleth Map: A Substitute to Traditional Legends

This article presents the use of the frequency histogram legend (FHL) as a substitute to traditional legends in both classed and unclassed choropleth maps. Great variation in the size of mapping units can hinder readers' ability to comprehend statistical distributions from a choropleth map. Replacing conventional legends with FHL can aid readers in their understanding of spatial as well as statistical distributions of the mapped data simultaneously. A customized mapping application was designed in ArcInfo 9.0 to test the use of FHL in both classed and unclassed choropleth maps. Frequency histogram legends were tested on different types of statistical distributions. Although the comparison of the results shows that the FHL works best for a Gaussian or close to a Gaussian distribution for eight or fewer classes, the customized application permits users to generate choropleth maps with frequency histogram legends for any type of statistical distribution with any number of classes. The analysis reveals that readers' background in statistics helped them to effectively utilize and interpret frequency histogram legends in the choropleth maps.     

Unclassed Animated Choropleth Maps

Abstract

The potential of unclassed animated choropleth maps as a solution to false patterns of geographic change arising from data classification is investigated. Old concerns about unclassed choropleth maps may be mitigated through map interactivity that offers four advantages over traditional data legends, and previous insights from testing static choropleth maps do not necessarily translate to animated cartography. Data from user testing revealed unclassed animated choropleth maps neither help nor hurt the ability of map readers to understand patterns of geographic change. However, the unclassed map (1) appeared 'less jumpy' to participants and was perceived to run at a slower pace (despite running at the same number of frames per second), and (2) subtle geographic shifts (e.g., seasonal unemployment cycles) were more readily noticed on the unclassed maps. Preliminary results also suggest classed data emphasise stability over time – while their unclassed counterparts improve our ability to see changes. This paper also outlines animated simultaneous contrast as a new perceptual issue in the creation of animated choropleth maps.     

一种顾及多重约束的三维地形简化方法

三维模型在许多领域内均有着越来越深入的应用,为保证三维模型在不同存储空间、不同图形绘制能力、不同显示分辨率的终端电子设备上显示的统一性和一致性,在很多情况下需要对三维模型进行适度的简化。对于三维地形而言,纹理颜色、地形区域边界和重要顶点是其非常重要的视觉特征,本文将这三项特征作为约束因子引入到三维地形的简化过程中,并根据这三项特征对现有的二次误差测度算法和边折叠代价的计算方法进行了改进,使其在三维地形简化过程中不会出现明显退化。本文还将改进后的算法与原来算法进行了实验对比,结果表明,改进后的简化算法不仅能够在不同精度上保持三维地形视觉上的一致性,而且产生的几何误差也相对较小。     

电子地图的色彩配合实验

在地图的色彩设计中,设计人员不仅要考虑色彩单独使用的效果,而且要考虑地图上各素的色彩配合,即各种色彩在图面上的整体感受效果。电子地图由于有极大的色彩选择空间,背景色不局限于白色,因而选色、配色比纸质地图更加复杂。用哪种简称颜色作为背景视觉效果较好？图面上各要素的色彩如何配合？针对这两个问题,作者设计了电子地图的一个色彩感受实验－色彩配合实验,利用自编的电子地图视觉感受测试构件（ＴＥＶＰ）进行了实验     

网络上分级统计地图制图软件的设计与开发

分析了网络环境中分级统计图表达信息的特点,阐述了交互式分级统计图的设计方法和思路,运用JavaApplet设计并实现了网络上分级统计地图制图子系统。     

Change Blindness in Animated Choropleth Maps: An Empirical Study

Animated choropleth maps enable cartographers to visualize time-series data in a way that congruently depicts change over time. However, users have difficulty apprehending information encoded within these displays, and often fail to detect important changes between adjacent scenes. Failures of visual experience, such as change blindness, threaten the effectiveness of dynamic geovisual displays, in which several important changes can occur simultaneously throughout the display. Animated choropleth maps require viewers not only to notice changes but also understand symbolic meanings encoded in rapid transitions between scenes. Graphic interpolation between key frames, also known as “in-betweening” or “tweening”, smoothes transitions and lengthens the duration of the transition between scenes in a dynamic sequence. Previous cartographic literature suggests tweening could be a potential solution for change blindness in the cartographic context. This article examines this issue of change blindness in the cartographic context and reports on a human subjects investigation designed to evaluate the influence of cartographic design variables on map readers' change detection abilities. Our results indicate that 1) map readers have difficulty detecting changes in animated choropleth maps, 2) map readers over-estimate their own change detection abilities, and 3) tweening influences the legibility of change in animated choropleth maps.     

利用地理属性量表的色盲人群地图色彩设计研究

根据地图表达地理属性的量表性质,将地图设色方案分为定性设色、顺序设色和双向设色等3种方式。基于这3种地图设色方式的特点,根据红-绿色盲的光谱特性,设计了一系列实验地图,通过颜色辨识的心理学实验,分析了红-绿色盲的视觉特征,初步揭示出一些针对红-绿色盲人群使用的地图设色原则,为制作红-绿色盲人群使用的地图提供了有效的参考。     

基于核密度估计方法的地图色域分析

针对地图制图中色彩选择较为困难的问题,该文收集国内外优秀地图、地图集、著作等上成功的设色方案,提取大量地图色彩样本。利用核密度估计方法,分析各类地图的常用色域区间,作为地图配色时的基色调。根据大量的地图色彩样本,利用定量的数学方法以及数据挖掘方法,探索地图色域特征分布规律。最后以收集的人口地图和环保地图颜色样本为例进行实验分析,对比证明本文方法能够很好地缩小地图色域选择区间,方便制图者根据地图种类选择颜色。     

A heuristic multi-criteria classification approach incorporating data quality information for choropleth mapping

ABSTRACT

Despite conceptual and technology advancements in cartography over the decades, choropleth map design and classification fail to address a fundamental issue: estimates that are statistically indifferent may be assigned to different classes on maps or vice versa. Recently, the class separability concept was introduced as a map classification criterion to evaluate the likelihood that estimates in two classes are statistical different. Unfortunately, choropleth maps created according to the separability criterion usually have highly unbalanced classes. To produce reasonably separable but more balanced classes, we propose a heuristic classification approach to consider not just the class separability criterion but also other classification criteria such as evenness and intra-class variability. A geovisual-analytic package was developed to support the heuristic mapping process to evaluate the trade-off between relevant criteria and to select the most preferable classification. Class break values can be adjusted to improve the performance of a classification.     

利用Munsell-HCV模型进行顾及土地利用专题信息的多色等高线配色研究

为改善专题图色彩协调的配色效果,本文基于Munsell-HCV色彩调和理论提出一种与土地利用图斑色彩调和的多色等高线配色方法。将等高线调和配色问题分解为类属调和、秩序调和和色差调和三个子问题。首先根据专题图用色习惯设置等高线基本色调并建立等高线调和色域,然后采用Munsell调和秩序算法计算调和色区间中与各图斑普染色协调的颜色作为候选等高线调和色,在此基础上结合图斑和等高线分布的区域差异分析建立等高线配色优先级,并根据人眼对色彩差别的感受规律进行多色等高线的配色平衡。实验对比和问卷调查研究表明,采用多色等高线的调和配色方法在土地利用专题图制作中是可行的,并取得了丰富细腻的图面视觉效果。     

Toward green cartography & visualization: a semantically-enriched method of generating energy-aware color schemes for digital maps

ABSTRACT

We introduce a semantically-enriched method of generating color schemes for various types of digital maps that reduces the energy consumption of the display device while preserving the quality of the original design. Energy-aware design intersects two important trends in cartography. First, as more maps are viewed today on mobile, battery life has become a central constraint influencing design. Second, there is increasing need for green computing, which encourages the efficient use of energy to limit environmental impacts. This paper focuses on one important aspect of energy-aware cartography: color design. Existing research on energy-aware color adjustment methods apply broadly to images or websites. However, the colors used in maps have more structured semantic relationships than most documents viewed on mobile devices, and efforts to account for these relationships while reducing energy consumption are limited. To fill this gap, we mathematically formalize energy-aware map-color adjustment as a constrained optimization problem: we define energy consumption as the objective function and model the preservation of semantic relationships as the search constraints. We evaluate our proposed method against a common color dimming method using four maps with different semantic relationships. The evaluation suggests that our proposed method better preserves the original color semantics.     

An Evaluation of the Use of Grid Squares in Computerised Choropleth Maps

Abstract

There are numerous computer programs to produce choropleth maps and some work has also been published on the use of a grid matrix as a way of dividing an area into discrete units. The purpose of this paper is to combine the two approaches and evaluate the suitability of using a network of grid cells, each containing a representative value of the variable being mapped, as a way of producing choropleth maps on a computer.     

政区地图设色方案的自动实现

分析了政区地图的设色要求 ,阐述了色彩设计中的对比调和理论 ,以此为依据设计出相应色环 ,规定一种间色 ,在色环中确定这种间色的对比色和类似色的CMY配色值 ,依据一定的顺序 ,自动把颜色配置在全国政区图上 ,并对自动设色和人工设色结果进行了比较分析 ,表明在可视化环境中 ,自动设色的地图比没有或仅有较少制图知识的人设计出的地图工效高     

基于LIDAR数据的建筑物轮廓提取

建筑物轮廓的准确提取是建筑物三维重建中最重要的一步。本文在研究已有建筑物轮廓提取方法的基础上,针对LIDAR离散的点云数据,提出了一种自动快速提取建筑物轮廓信息的方法。首先通过点云数据生成城市的数字表面模型(DSM)和数字地面模型(DTM)相减计算得出规则化的数字表面模型(nDSM),进而将地面点和非地面点进行分类;其次,考虑到地物的几何特性,提出一种8邻域搜索的方法对非地面点点云进行分割,得到建筑物表面点云;最后运用基于梯度图的边界跟踪的方法来获取建筑物的轮廓信息。实验表明:该方法能有效地提取建筑物轮廓。     

Measuring the influence of map label density on perceived complexity: a user study using eye tracking

ABSTRACT

We combine eye tracking and a questionnaire-based approach to explore the influence of label density on the perceived visual complexity of maps. We design two experiments in which participants are asked to search for the names of point features on maps and to rate the map complexity and legibility for different label densities. Specifically, we conduct a highly controlled experiment in which all the map variables except the label density are held constant (the controlled experiment). Then, we conduct a second experiment following the same protocol but using real maps as visual stimuli (the real-map experiment) to verify if the results of the controlled experiment were applicable to real maps. The results of both experiments indicate a significantly positive correlation between perceived visual complexity and label density and between the response time in visual search tasks and label density. Surprisingly, we observe a significant inverse correlation between the label density and two eye movement parameters (fixation duration and fixation frequency) between the two experiments. We discuss how the variables of real maps might have affected these eye movement parameters and why the results of the two experiments are inconsistent. Our findings suggest that eye tracking parameters are not reliable indicators of map complexity. These empirical results can be helpful to future map design and map complexity investigation.     

分区统计地图上符号的视觉搜寻和认知工效研究

根据某地区的分区统计数据和有关图集，总结设计出4种方案的分区统计地图，在自行编制的认知测试软件上进行了目标搜寻测试，结果表明，在分区统计地图上搜寻目标时，视觉系统运用了平行加工策略和序列加工策略，4个方案的目标搜寻平均反应时间和正确率受到这两种策略的影响。     

A Cognitive Map Experiment: Mental Representations and the Encoding Process

Researchers have long debated the mental representation of knowledge. The theories initially spawned by this debate were propositional theoty, imagery theory, and dual-coding theory. Related research further suggests that knowledge encoding processes such as landmark-based and path-based learning may also affect these representations. Such theories form a basis from which cartographers can begin to explore the mental representations of spatial knowledge. The purpose of this study was to assess the mental organization of spatial information and to examine the effect of varying the encoding process. An experiment was conducted in which subjects studied a map presented to them using one of three encoding processes and one of two grid conditions. Subjects then examined a series of test maps and determined whether each map was the same as or different from the original studied map. Test maps that differed from the original map studied were modified by either replacing, displacing, or reversing the perspective of a map object. Results of the study indicated that the type of encoding process, type of map modification, and type of spatial object manipulated all significantly affected the accuracy with which subjects completed the tasks.     

3D地图打印技术研究

2015年9月美国3D打印机在河北省制图院落户。笔者结合其配套打印软件,组织技术人员反复实践,研发出一套符合我国实际的3D地图生产工艺流程,成功解决了基础地理信息国标数据格式向3D格式数据转换、3D地形模型编辑、3D符号设计等一系列难题。该技术融合了3ds Max、ArcGIS、Global Mapper等多种软件制图技术,具备实用性强、可操作性强、推广价值较高等优点。产品涵盖晕渲地图、正射影像地图、专题地图、物理沙盘等品种。3D打印地图具备以下特点：色彩鲜艳、地形直观逼真;色彩设计自由,富于变化;精度高;可接收多源数据;生产效率高。