Bug report #18083

Simplify map tool - don't use douglas-peucker simplification

Added by Nyall Dawson almost 6 years ago. Updated over 5 years ago.

Assignee:Denis Rouzaud
Category:Map Tools
Affected QGIS version:master Regression?:No
Operating System: Easy fix?:No
Pull Request or Patch supplied:No Resolution:fixed/implemented
Crashes QGIS or corrupts data:No Copied to github as #:25979


The simplify map tool currently forces Douglas-Peucker simplification (via the QgsGeometry::simplify method). Unfortunately this simplification technique is not ideal as it preserves jagged spikes within line work, making it unusable for cartographic simplification.

A better choice would be to utilise Visvalingam simplification (which is available from the QgsMapToPixelGeometrySimplifier class) - this simplification technique prefers to eliminate narrow jagged spikes, resulting in much more pleasing cartographic simplification.

(Or better - expose this choice to users so that they can select an appropriate simplification technique for their requirements)

Associated revisions

Revision dce21882
Added by Nyall Dawson almost 6 years ago

[FEATURE] Add choice of simplification method to simplify map tool

Allows different techniques to be used for simplification, including
the more cartographically pleasing "Visvalingam" simplification algorithm.

Fixes #18083


#1 Updated by Nyall Dawson almost 6 years ago

  • % Done changed from 0 to 100
  • Status changed from Open to Closed

#2 Updated by Giovanni Manghi over 5 years ago

  • Resolution set to fixed/implemented

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