[gdal-dev] Hillshade + Topographic Map??

Frank Broniewski brfr at metrico.lu
Tue Feb 21 08:14:08 EST 2012


the standard procedure for creating topo-maps is to overlay your land 
coverage map with a semi-transparent hillshading. I don't know if 
there's a tool for combining/adding two raster maps together in gdal, 
but this is a rather standard procedure in any GIS. In QGIS, for 
example, you can adjust the layer transparency slider to get the effect.

If you want to create a more permament combination of the land coverage 
and hillshade, you can use a software like GIMP to combine the two maps.

Mapserver may be able to create a georeferenced version of your 
combination also, as does mapnik. The biggest problem is probably to 
overcome the alpha-transparency for your hillshading, which is not 
something that every raster library is able to handle well.


Am 21.02.2012 11:01, schrieb TJMartin:
> Hi
> I have managed to create a hillshade using gdaldem and I have my original
> topographic rasters. However I do not want the standard grey hillshad or
> apply a colour ramp.
> Is there a way to combine the hillshade and topo map together - ie add a
> transparency or opacity to the hillshade.
> I have looked at Photopshop and ImageMagik but the results are then not
> supported in QGIS etc
> After a trawl through the web the only entry is an ArGIS 10 tutorial
> http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//009t000001v1000000
> Hopefully that will explain what I would like to achieve
> thanks for anyones help
> Tim
> --
> View this message in context: http://osgeo-org.1560.n6.nabble.com/Hillshade-Topographic-Map-tp4490698p4490698.html
> Sent from the GDAL - Dev mailing list archive at Nabble.com.
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