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1.
The quality of dynamic map symbols plays an important role in the representation of spatial-temporal changes. This paper reports an investigation into the quality of dynamic symbols. To assess the quality of such symbols, a set of traffic flow data is used for the production of different kinds of dynamic maps, with focus on four variables, i.e. size, color, frame rate and display format. Two quantitative measures are used for analysis, i.e. deviation and response time. A set of traffic data is used for the production of dynamic maps for evaluation. The experimental results show that the size is more efficient and more effective than color for dynamic maps with the same frame rate and display format. The most efficient and effective color class number is 10 on the large format display such as 1024 × 768 pixels. And the most efficient and effective size class number is 15 on large format display such as 1024 × 768 pixels. The effective frame rate for dynamic map animation is smaller than that of the general animation on the Internet or Quick Time and AVI format video. The most efficient and most effective frame rate is 3 frames per second in the color expression and 6 frames per second in the size expression. In sum, the effective and efficient value of color, size and frame rate on large format display is less than the value on the small format display. These results suggest the frame rate should be reduced on the small format display. It is hoped that the results from this study will be of help in the design of effective and efficient dynamic map symbols for geographical information visualization.  相似文献   

2.
邓淑丹  江文浦 《测绘科学》2010,35(1):136-138
目前网络动态地图符号主要分为两种,一种是实时数据动态符号;另一种是由符号内的动画表现动态性,其变化与地物实时属性变化没有关系。第一种研究较多,应用领域也比较广泛。而第二种研究一般是作为第一种的辅助,并没有进行系统的研究。本文基于静态符号的设计基础和原则上,提出了网络动画类动态符号的相关概念、设计原则,以及动态符号在地图中显示原则。  相似文献   

3.
《The Cartographic journal》2013,50(3):229-244
Abstract

The age of the Internet poses new challenges to cartography. While cartographic animation has become a practical alternative, it is mostly used to depict both spatio-temporal and non-temporal changes. The paper concentrates on the use of dynamic symbols on a static base map. A visual test was carried out to obtain some perspectives about the cartographic communication of blinking point and line symbols. The results confirmed that dynamic symbols tended to attract the attention of the users in general and even in situations when the foreground–background contrasts were poor. Their effectiveness was more pronounced with symbols of a larger size but tended to diminish with an increasing number of blinking symbols. It was also observed that users were able to perceive differences in the frequency of flickering, particularly when the variation was large. The line animation method (marquee and grow-out) did not yield a substantial difference in visual responses in the case of blinking line symbols.  相似文献   

4.
符号是以图形的方式对地图中的要素进行描述,以找出并显示定性和定量关系。地质符号作为地质语言在地质图件的制作和输出中起着非常重要的作用。美国ESRI公司开发的ArcGIS是功能较强大的GIS软件,但是,其ArcMap模块中自带的符号库不能满足地质行业需求,因此,必须为它建立符合地质图图式要求的符号库。本文重点论述了在ArcGIS环境下地质符号库的设计方法,并分别讨论了点状符号、线状符号和面状符号的实现方式。  相似文献   

5.
为解决网络地图个性化推荐过程中点状符号用户兴趣分析结果准确性低的问题,提出了一种基于眼动数据的网络地图点状符号用户兴趣分析方法。利用空间认知测试法筛选39名认知能力一致的被试者参与实验,使用眼动仪采集被试者在浏览4类点状符号素材过程中的眼动数据,同时记录被试者的鼠标数据;分别计算时间、次数与尺寸类型眼动数据用户兴趣度,利用熵权法将3类数据进行整合,设计了一种基于多项眼动数据的用户兴趣度计算方法。研究结果表明,用户兴趣度分析结果正确率为85.9%,优于鼠标数据,证明所提方法能够有效分析用户兴趣,点状符号用户兴趣度计算公式稳定可靠,有助于提升个性化推荐结果的准确度。  相似文献   

6.
ABSTRACT

Given the rising availability of alternative ways of spatial data mapping, there is a growing need to study their usability. An important aspect here is the diversity of the cartographic visualizations that are used to draw conclusions about the usability of various mapping techniques. In our study we evaluated the usability of six various mapping techniques used in presenting spatial accessibility, taking into consideration four components: effectiveness and efficiency (objective criteria) and graphical attractiveness and user-perceived effectiveness (subjective criteria). Using Internet questionnaires, we conducted a graphical perception experiment with respondents performing tasks on a hypothetical monocentric road network model displayed using mapping techniques of spatial accessibility, differing in the applied parameters of graphical and non-graphical factors influencing effectiveness and efficiency. The results showed that non-graphical factors had a greater influence than the graphical factors. In total usability comparison the three-dimensional (3D) point technique was ranked the highest, while the worst result was achieved by the 3D area technique. The proposed graphical form of study results made it possible to compare the influence of various effectiveness factors, to analyze mapping techniques in terms of considered criteria and finally to present their total usability using a chart inspired by Uhorczak’s typogram.  相似文献   

7.
王磊 《测绘工程》2012,21(1):39-43
基于GIS库和图形库"两库合一"与"符号多重嵌套"思想,利用模板控制技术,采用程序设计和参数设计相结合的方式,对地图符号化模块进行设计,并基于模板跨平台实现相关功能,对空间数据(点、线、面、注记)进行静、动态符号化,实现空间数据符号化显示、数据转换等功能。  相似文献   

8.
针埘GDI+绘制复杂线状符号存在符号不可编辑与遮捎等问题,设计了一种可编辑的复杂线状符号的组织方法,该方法将复杂线状符号分解为实线、虚线和点线蔓种基本单元,进而设计了基于这一种基本单元的复杂线状符号参数描述方法,解决了GDI+绘制复杂线状符号存在符号不可编辑与遮挡等问题。采用C#实现了可编辑线状符弓库的设计与开发.建立了1:10000地形图符号库。最后,对本文方法与GDI+方法的绘制效率进行了比较试验。试验表明本文方法不仅解决了GDI+绘制复杂线状符号存在符号不可编辑与遮挡等问题.并且绘制效率也明显优于GDI+方法.  相似文献   

9.
ABSTRACT

Proportional point symbols are commonly used in map displays. However, when such displays are zoomed out, the available map space shrinks and consequently symbols overlap and the display suffers from visual clutter. Therefore, solutions are needed to reduce visual clutter in zoomable map displays that contain proportional point symbols. The authors add to the body of knowledge through the investigation of the performance of three solutions: aggregation of unit areas, the displacement of overlapping symbols, and modified symbolization; four variations of modified symbolization are examined in detail. The original study begins with a consideration of the strengths and weaknesses of the solutions, with an emphasis on information loss. Thereafter, user sessions with 165 participants are arranged to gain empirical evidence of the performance of the solutions. The results reveal that although participants zoom out the map to zoom levels that implement visual clutter reduction techniques, they tend to zoom in the map and pan it to examine specific areas. Moreover, they willingly use the map with aggregated unit areas in cases when the solution facilitates task accomplishment. A certain amount of skepticism attaches to the solution that displaces overlapping symbols.  相似文献   

10.
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.  相似文献   

11.
基于3DS MAX的地质景观动态模拟与仿真   总被引:3,自引:0,他引:3  
分析了三维可视化及仿真动画技术在地质景观成因动态模拟与仿真过程中的应用价值,重点论述了如何对地质景观形成演化在 时间尺度上进行模拟和仿真表达。基于3DS MAX各种建模工具,充分利用现有资料和数据,进行地质景观形成过程动态模拟,实现逼真 的视觉仿真效果。通过对长白山火山形成过程的动态模拟和仿真研究,阐明了利用3DS MAX进行地质景观成因动态模拟的适用性、潜力 及相关技巧,取得了理想效果。  相似文献   

12.
本文基于用图案来组成图形符号的基本思想,引入图案拓扑等价的观点,较系统地对专题地图中点、线、面三类符号的绘制作了一些探讨。  相似文献   

13.
MicroStation中地图符号的制作与使用   总被引:1,自引:0,他引:1  
详细论述了在MicroStation中制作和使用地形图符号的方法。点状符号按照制作单元的方法制作,存放在单元库中,通过对单元的类型和放置方法的分析,建议主符号设计成点单元,使用时按共享方式放置。线状称号按照线编辑器中自定义线型的制作方法制作,存放在线型库中,结合半依比例尺水闸符号的制作实例具体介绍自定义线型制作的基本方法。面状符号利用MicroStation提供的功能,通过编程来完成。  相似文献   

14.
主要阐述编制综合性专题地图集时,符号系统设计应遵循的规则,涉及图集中经常用到的一些符号、图表符号制作,及构建这些符号系统时需要注意的细节问题,列举了一些制作专题地图符号、图表方法及对极值数据的处理方法。通过对编制专题地图符号极易出现的问题总结,可以在以后的编制地图集过程中,避免因制作专题符号不科学而引发读图人对数量指标估读的错误认知,从而做出错误的评价,实现专题地图符号的科学表达及具有可量算性特质。本文所列举事例均来自《河北省地图集》专题地图。  相似文献   

15.
We present a new procedure to compute dense 3D point clouds from a sequential set of images. This procedure is considered as a second step of a three-step algorithm for 3D reconstruction from image sequences, whose first step consists of image orientation and the last step is shape reconstruction. We assume that the camera matrices as well as a sparse set of 3D points are available and we strive for obtaining a dense and reliable 3D point cloud. Three novel ideas are presented: (1) for sparse tracking and triangulation, the search space for correspondences is reduced to a line segment by means of known camera matrices and disparity ranges are provided by triangular meshes from the already available points; (2) triangular meshes from extended sets of points are used for dense matching, because these meshes help to reconstruct points in weakly textured areas and present a natural way to obtain subpixel accuracy; (3) two non-local optimization methods, namely, 1D dynamic programming along horizontal lines and semi-global optimization were employed for refinement of local results obtained from an arbitrary number of images. All methods were extensively tested on a benchmark data set and an infrared video sequence. Both visual and quantitative results demonstrate the effectiveness of our algorithm.  相似文献   

16.
GIScience scholars have identified map tours as an important visualization type for communicating spatial information: map tours are animations where the virtual camera moves through space and are common on the web, mobile devices, and television. Understanding how to enhance their effectiveness is timely because of recent, growing interest in virtual reality and animated map presentation tools such as Esri Story Maps? and Google Earth? tours. Despite this popularity, little empirical evidence exists about how people learn from map tours and how they should best be designed to improve effectiveness. This research is aimed at answering that need. An empirical study is described, which was designed to understand how virtual camera speed, path, and dynamic tilting within a map tour influence subjects’ ability to develop survey knowledge. The results of the experiment show that paths encompassing overviews of the landscape improve the viewer’s ability to build up survey knowledge; that tilting appears to have a much weaker effect; and that combining fast speed and a difficult path within a map tour increases the viewer’s cognitive load.  相似文献   

17.
ABSTRACT

Social, economic, and environmental statistical data associated with geographic points are currently globally available in large amounts. When conventional thematic maps, such as proportional symbol maps or point diagram maps, are used to represent these data, the maps appear cluttered if the point data volumes are relatively large or cover a relatively dense region. To overcome these limitations, we propose a new type of thematic map for statistical data associated with geographic points: the point grid map. In a point grid map, an input point data set is transformed into a grid in which each point is represented by a square grid cell of equal size while preserving the relative position of each point, which leads to a clear and uncluttered appearance, and the grid cells can be shaded or patterned with symbols or diagrams according to the attributes of the points. We present an algorithm to construct a point grid map and test it with several simulated and real data sets. Furthermore, we present some variants of the point grid map.  相似文献   

18.
The cartographic representation of geographic phenomena in the space–time cube comes with special challenges and opportunities when compared with two-dimensional maps. While the added dimension allows the display of attributes that vary with time, it is difficult to display rapidly varying temporal data given the limited display height. In this study, we adapt 2D cyclic point symbols to construct 3D surfaces designed along a helical path for the space–time cube. We demonstrate how these complex?3D helical surfaces can display detailed data, including data reported daily over 100 years and data reported in four-hour intervals over a year. To create the point symbols, each value is plotted along the curve of a helix, with each turn of the helix representing one year or week, respectively. The model is modified by varying the radii from the time axis to all points using the attribute value, in these cases maximum daily temperature and four-hourly ridership, and then creating a triangulated surface from the resulting points. Using techniques common to terrain representation, we apply hue and saturation to the surface based on attribute values, and lightness based on relief shading. Multiple surfaces can be displayed in a space–time cube with a consistent time interval facing the viewer, and the surfaces or viewer perspective can be rotated to display synchronized variations. We see this method as one example of how cartographic design can refine or enhance operations in the space–time cube.  相似文献   

19.
针对界址点测量误差来源中起始误差含义、大小及其影响程度缺少精确分析等问题,基于RTK规范和地籍调查规程的相关技术指标,采用理论分析与实证相结合的方法,界定了起始误差的含义,得出了符合实际情况的起始误差的大小及其影响程度。采用极坐标法测量界址点时,其起算误差应理解为测站点与定向点之间的相对中误差;起算误差是界址点测量的主要误差来源之一;实践中定向边长应尽可能选用长距离已知边,定向边长不宜小于测站最大观测距1/2。理清了界址点测量中起始误差的含义,理论与实证的起算误差大小相当,能够用于支撑相关规程制定和修改地籍图根控制测量技术指标。  相似文献   

20.
We provide a research agenda for the International Cartographic Association's Commission on Visualization and Virtual Environment Working Group on Cognitive and Usability Issues in Geovisualization. Developments in hardware and software have led to (and will continue to stimulate) numerous novel methods for visualizing geospatial data. It is our belief that these novel methods will be of little use if they are not developed within a theoretical cognitive framework and iteratively tested using usability engineering principles. We argue that cognitive and usability issues should be considered in the context of six major research themes: 1) geospatial virtual environments (GeoVEs); 2) dynamic representations (including animated and interactive maps); 3) metaphors and schemata in user interface design; 4) individual and group differences; 5) collaborative geovisualization; and 6) evaluating the effectiveness of geovisualization methods. A key point underlying our use of theoretical cognitive principles is that traditional cognitive theory for static two-dimensional maps may not be applicable to interactive three-dimensional immersive GeoVEs and dynamic representations—thus new cognitive theory may need to be developed. Usability engineering extends beyond the traditional cartographic practice of "user testing" by evaluating software effectiveness throughout a lifecycle (including design, development, and deployment). Applying usability engineering to geovisualization, however, may be problematic because of the novelty of geovisualization and the associated difficulty of defining the nature of users and their tasks. Tackling the research themes is likely to require an interdisciplinary effort involving geographic information scientists, cognitive scientists, usability engineers, computer scientists, and others.  相似文献   

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