[GRASSLIST:4000] Re: How to improve the resolution of r.in.gdal?

[Steve Kimball]

Thanks.  Setting the region boundaries to match the raster with
"g.region rast= " worked much better.  Displaying vector maps over
raster maps
seems to work fine ... so no need to converting to raster.

Also shade.rel.sh in $GISBASE/scripts seems to work well with 
the current USGS STDS DEM files.   The output looks best with
color=grey.
Is there a colormap that makes terrain like colors?
Low elevations in green and higher in brown?

Steve

Glynn Clements wrote:
> 
> Steve Kimball wrote:
> 
> > I successfully read in a USGS STDS 7.5 min DEM file with r.in.gdal.
> > Using the CATD file worked nicely.
> > Then using d.rast map= the display monitor resolution was not what I
> > expected.
> > After zooming in the elevation map was not as clear MS/DOS display
> > utility using the same data.  Is the WIND file used for raster
> > resolution?
> 
> Raster import utilities import the data cell-for-cell, with no scaling
> or resampling. However, most programs which access the imported raster
> maps (including d.rast) will automatically rescale the raster using
> the current region settings.
> 
> You can set the region boundaries and resolution to match a particular
> raster using "g.region rast=...".
> 
> > Also I'd like to overlay the DEM raster data with vector data.
> > So I used v.to.rast to create a raster map layer and it's resolution
> > was worse than I expected.  The origional vector map had better
> > rseolution.
> 
> Vector maps have infinite resolution; converting a vector map to a
> raster map will always lose accuracy. But you determine the resolution
> of the raster produced by v.to.rast via the region settings.
> 
> --
> Glynn Clements <glynn.clements at virgin.net>