ST_SimplifyVW — Returns a simplified version of a geometry, using the Visvalingam-Whyatt algorithm
geometry ST_SimplifyVW(geometry geomA, float tolerance
Returns a "simplified" version of the given geometry using the Visvalingam-Whyatt algorithm. Will actually do something only with (multi)lines and (multi)polygons but you can safely call it with any kind of geometry. Since simplification occurs on a object-by-object basis you can also feed a GeometryCollection to this function.
Note that returned geometry might lose its simplicity (see ST_IsSimple)
Note topology may not be preserved and may result in invalid geometries. Use (see ST_SimplifyPreserveTopology) to preserve topology.
This function handles 3D and the third dimension will affect the result.
A LineString is simplified with a minimum area threshold of 30.
select ST_AsText(ST_SimplifyVW(geom,30)) simplified FROM (SELECT 'LINESTRING(5 2, 3 8, 6 20, 7 25, 10 10)'::geometry geom) As foo; -result simplified ------------------------------ LINESTRING(5 2,7 25,10 10)
ST_SetEffectiveArea, ST_Simplify, ST_SimplifyPreserveTopology, Topology ST_Simplify