[gdal-dev] GDAL Speed Optimization

[Iván Sánchez Ortega]

El día Thursday 10 June 2010 09:49:01, Stefano Moratto dijo:
> I use GDAL to download tiles (jpeg) from OpenstreetMap and to compose a
> bitmap of the area that is being viewed. The resulting bitmap (not
> compressed) is warped  and displayed.

Hhhhmmm. Personally, I think you're doing it wrong.

If you really need speed for custom reprojections of OSM data, the best thing 
to do is to render the data locally with Mapnik. i.e.:

- Download a planet file
- Put it in PostGIS via osm2pgsql
- Configure Mapnik to use the projection you need
- Use Mapnik to get the desired area rendered

You might incur in a speed penalty due to the rendering itself, but you 
guarantee that there will be no artifacts due to the image warping.

And also, you might get a boost by reprojecting the vector data inside PostGIS 
so Mapnik doesn't have to reproject it on-the-fly.


I realise that setting Mapnik is quite a lot of work at first, but it's an 
idea that is worth considering in your case.


Cheers,
-- 
Iván Sánchez Ortega <ivan at sanchezortega.es>

Un ordenador no es una televisión ni un microondas: es una herramienta 
compleja.