[GIS] “Simplify tolerance” in QGIS’s Simplify geometries tool

geoprocessingqgissimplify

I am trying to use QGIS 2.8 to simplify vector geometries. But I do not understand the significance of the Simplify tolerance value in the Simplify geometries tool.

The documentation does not explain it.

Best Answer

QGIS uses the Douglas-Peucker algorithm (slightly modified to handle closed loop like polygons, I think) and the unit of the tolerance parameter is the same as the unit of the reference system. Points are removed if the distance with the tentative simplified line is smaller than the tolerance.