QGIS Python Plugins Repository
Cartographic Line Generalization
Generalize lines suitable for presentation on printed or screen maps.
Algorithm gives lines (contours, coastlines, rivers, buildings etc.) on map with good geometrical and visual properties suitable for presentation on paper or screen maps. Level of generalization is controlled only by map scale making it very simple to use. If the result still looks too detailed or too coarse for some purpose, just change the scale parameter. It has distinct property of area preservation of features. This ensures that polygons do not collapse to lines or points, and also ensures closeness of input and generalized line. Nevertheless, topological issues are possible, e.g. self-intersections or intersections of features. The typical generalization combines simplification followed by smoothing. Generalization algorithms are based on area preserving approach known from generalization theory. This simulates manual generalization, and parameters of the algorithms were defined by analysing manually generalized lines in different scales.
TIPS:
- Input vector data must be in projected coordinate system.
- Default scale for generalization is scale of current map view, change if necessary.
- For buildings (or predominantly rectangular lines or polygons set algorithm to "Orthogonal segments".
- If "Remove small areas" is selected, algorithm will automatically delete small areal objects for given scale. One can do manual filtering of small objects by area and appropriate threshold, too.
- Author
- Drazen Tutic
- Maintainer
- dtutic
- Tags
- generalization , simplification , smoothing , cartography , area preserving
- Plugin home page
- http://github.com/dtutic/CartoLineGen
- Tracker
- Browse and report bugs
- Code repository
- http://github.com/geof-osgl/CartoLineGen
- Latest stable version
- 3.2.2
- Plugin ID
-
1535
Sustaining Members
