[gdal-dev] Re-projecting with valid geometry

[Even Rouault]

Hi,

> 
> Interestingly table reprojected with ogr2ogr shows errors on different
> features then errors generated by PostGIS's ST_Transform() function.

This is a bit surprising. ogr2ogr applies reprojection on each point of source 
geometries. I would have expected ST_Transform() to do the same.

> 
> I wonder if there are some steps I can take before re-projecting or
> afterward, that will produce valid transformation, without need of
> correcting erroneous geometries by hand after re-projecting data?

Not sure if this qualified of a by hand correction, but you may want to try 
ST_MakeValid() after ST_Transform() : 
http://postgis.org/docs/ST_MakeValid.html

Even

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