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Simultaneous graphic generalization of vector data sets

Harrie, Lars LU and Sarjakoski, T (2002) In GeoInformatica 6(3). p.233-261
Abstract
Manual cartographic generalization is a simultaneous process. However, most automatic approaches so far have been sequential; generalization operators are applied one at a time in a certain order. This has been the case both for model generalization (generalization of the conceptual model) and graphic generalization. Our research seeks to demonstrate that the graphic part of cartographic generalization can be formulated as an optimization problem and accordingly be solved in a single step. This paper deals with several issues regarding this optimization approach. Firstly, a set of appropriate analytical constraints for the generalization process is given, as well as rules for when to apply these constraints. In our approach, we are limited... (More)
Manual cartographic generalization is a simultaneous process. However, most automatic approaches so far have been sequential; generalization operators are applied one at a time in a certain order. This has been the case both for model generalization (generalization of the conceptual model) and graphic generalization. Our research seeks to demonstrate that the graphic part of cartographic generalization can be formulated as an optimization problem and accordingly be solved in a single step. This paper deals with several issues regarding this optimization approach. Firstly, a set of appropriate analytical constraints for the generalization process is given, as well as rules for when to apply these constraints. In our approach, we are limited to formulating these constraints on point locations. Secondly, least-squares adjustment is proposed to find the optimal solution according to the constraints. Finally, the conjugate-gradients method is recommended for solving the normal equations. A prototype system for simultaneous graphic generalization has been implemented in C++, which communicates with a commercial map production system. Results from three tests of the prototype system are included in the paper. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
conjugate-gradients method, Delaunay triangulation, least-squares adjustment, map generalization, graphic generalization
in
GeoInformatica
volume
6
issue
3
pages
233 - 261
publisher
Springer
external identifiers
  • wos:000177422900002
  • scopus:0036741719
ISSN
1384-6175
DOI
10.1023/A:1019765902987
language
English
LU publication?
yes
id
ded93b0d-7204-4560-baa6-c5a8e6c0add2 (old id 331027)
date added to LUP
2007-08-24 15:29:15
date last changed
2017-10-01 03:47:00
@article{ded93b0d-7204-4560-baa6-c5a8e6c0add2,
  abstract     = {Manual cartographic generalization is a simultaneous process. However, most automatic approaches so far have been sequential; generalization operators are applied one at a time in a certain order. This has been the case both for model generalization (generalization of the conceptual model) and graphic generalization. Our research seeks to demonstrate that the graphic part of cartographic generalization can be formulated as an optimization problem and accordingly be solved in a single step. This paper deals with several issues regarding this optimization approach. Firstly, a set of appropriate analytical constraints for the generalization process is given, as well as rules for when to apply these constraints. In our approach, we are limited to formulating these constraints on point locations. Secondly, least-squares adjustment is proposed to find the optimal solution according to the constraints. Finally, the conjugate-gradients method is recommended for solving the normal equations. A prototype system for simultaneous graphic generalization has been implemented in C++, which communicates with a commercial map production system. Results from three tests of the prototype system are included in the paper.},
  author       = {Harrie, Lars and Sarjakoski, T},
  issn         = {1384-6175},
  keyword      = {conjugate-gradients method,Delaunay triangulation,least-squares adjustment,map generalization,graphic generalization},
  language     = {eng},
  number       = {3},
  pages        = {233--261},
  publisher    = {Springer},
  series       = {GeoInformatica},
  title        = {Simultaneous graphic generalization of vector data sets},
  url          = {http://dx.doi.org/10.1023/A:1019765902987},
  volume       = {6},
  year         = {2002},
}