Schematic road network map progressive generalization based on multiple constraints     

Weihua Dong  Qingsheng Guo  Jiping Liu 《地球空间信息科学学报》2013,16(3):215-220

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.  相似文献   

EXPERIMENTS ON THE GROUP GENERALIZATIONG OF CONTOUR LINES FOR TOPOGRAPHIC MAPS     

FEI Lifan 《地球空间信息科学学报》2013,16(1):85-95

ABSTRACT

This paper analyzes the advantages and disadvantages of two technical lines for automatic group generalization of contour lines. The author suggests that it is possible to get faster and better generalization results if we simulate the intelligence of human experts in program designing, retrieve geomorphological structural information using the input data of 2-D contour lines and derive and output the generalized 2-D results directly.  相似文献   

Progressive graphic simplification of contours based on spatial reasoning     

Guo Qingsheng  Wang Tao  Mao Jianhua  Wu Hehai 《地球空间信息科学学报》2013,16(4):67-72

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.  相似文献   

Scale-specific automated line simplification by vertex clustering on a hexagonal tessellation     

Paulo Raposo 《制图学和地理信息科学》2013,40(5):427-443

A new method of cartographic line simplification is presented. Regular hexagonal tessellations are used to sample lines for simplification, where hexagon width, reflecting sampling fidelity, is varied in proportion to target scale and drawing resolution. Tesserae constitute loci at which new sets of vertices are defined by vertex clustering quantization, and these vertices are used to compose simplified lines retaining only visually resolvable detail at target scale. Hexagon scaling is informed by the Nyquist–Shannon sampling theorem. The hexagonal quantization algorithm is also compared to an implementation of the Li–Openshaw raster-vector algorithm, which undertakes a similar process using square raster cells. Lines produced by either algorithm using like tessera widths are compared for fidelity to the original line in two ways: Hausdorff distances to the original lines are statistically analyzed, and simplified lines are presented against input lines for visual inspection. Results show that hexagonal quantization offers advantages over square tessellations for vertex clustering line simplification in that simplified lines are significantly less displaced from input lines. Visual inspection suggests lines produced by hexagonal quantization retain informative geographical shapes for greater differences in scale than do those produced by quantization in square cells. This study yields a scale-specific cartographic line simplification algorithm, following Li and Openshaw's natural principle, which is readily applicable to cartographic linework. Open-source Java code implementing the hexagonal quantization algorithm is available online.  相似文献   

The “M” in digital elevation models     

XiaoHang Liu  Hai Hu  Peng Hu 《制图学和地理信息科学》2013,40(3):235-243

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Editorial     

Michael Leitner 《制图学和地理信息科学》2013,40(1):1-2

This article presents research that implements a fully automated workflow to generalize a 1:50k map from 1:10k data. This is the first time that a complete topographic map has been generalized without any human interaction. More noteworthy is that the resulting map is good enough to replace the existing map. Specifications for the automated process were established as part of this research.

Replication of the existing map was not the aim, because feasibility of automated generalization is better when compliance with traditional generalizations rules is loosened and alternate approaches are acceptable. Indeed, users valued the currency and relevancy of geographical information more than complying with all existing cartographic guidelines. The development of the workflow thus started with the creation of a test map with automated generalization operations. The reason for the test map was to show what is technologically possible and to refine the results based on iterative users’ evaluation. The generalization operations (200 in total) containing the relevant algorithms and parameter values were developed and implemented in one model. Particular effort was made to enrich the source data in order to improve the results. The model is context aware which means it is able to apply different algorithms or adjust parameter values in accordance with a specific area. The result of the research is a fully automated generalization workflow that produces a countrywide map at scale 1:50k from 1:10k data in 50 hours.

A fully automated workflow may be the only way to produce flexible and on-demand products; consequently, the results were implemented as a new production line in 2013. Issues for further research have been identified.  相似文献   

Obituary     

《The Cartographic journal》2013,50(4):371-373

Abstract

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Positional quality control in cartography based on linear features represents an evolution of the traditional procedures based on points. These methods have been developed independently or theoretically and applied as examples to small, disparate databases. In this paper, we present a unified, complete methodology using the existing methods and applying them to official cartographic databases in the region of Andalucía (southern Spain). For this purpose, we use a sample of roadways observed with GPS. The results obtained demonstrate the viability of this control and the potential use of this methodology compared to traditional point-based quality control.  相似文献   

The Use of Mental and Sketch Maps as a Tool to Evaluate Cartography Teaching Effectiveness     

Kamil Nieścioruk 《The Cartographic journal》2013,50(2):186-196

The paper describes mental maps and their use in teaching process. The survey conducted among students of geodesy and cartography resulted in 124 sketches. They were analysed from the point of view of cartographic methodology and used methods of presentation. The different elements and methods were counted and helped in evaluation of teaching process effectiveness, showing changes in students’ knowledge of certain rules of cartographic language and design and their applications. As the survey was conducted in relation to courses taught, the results are of great value in increasing the quality of cartographic content of these courses and teaching methods.  相似文献   

The Society of University Cartographers – Its Growth and International Status     

Michael Wood 《The Cartographic journal》2013,50(3):224-227

An attempt to capture and reflect the history, evolution, nature and status of the Society of Cartographers (SoC). Although a small organization numerically, the skill, expertise and dedication of its active members, though summer schools, technical journal, newsletters and especially its rich and informative website, are providing access to knowledge and experience both nationally and globally. This influence is also reflected through the direct involvement of leading SoC office-holders in other national and international mapping organisations. The SoC clearly punches above its weight. It has made a difference to the world of mapping, and continues to do so  相似文献   

Fifty Years of The Cartographic Journal   总被引：1，自引：1，他引：0  

Kenneth Field 《The Cartographic journal》2013,50(3):228-231

The Cartographic Journal was established a year after the founding of the British Cartographic Society in 1963 and so 2014 marked 50 years since the first, general-distribution journal of cartography in English was published. This paper offers a brief account of its genesis and its development in reflecting and shaping the leading themes in cartographic research over the years, and explains how the Society's flagship publication and an official journal of the ICA (International Cartographic Association) has maintained its position at the forefront of academic publishing in cartography.  相似文献