[GRASSLIST:4811] Re: r.in.tiff: problems

[Michael Barton]

Lawrence,

I see others have offered more comprehensive solutions. However, this might
help you and others with r.in.tiff.

Based on my experience with the module, r.in.tiff assumes that you have a
RGB color file and tries to parse it into red, green, and blue channels. In
your case, you have a single channel elevation file. Both your green (*.g)
and blue (*.b) bands are probably identical (subtract one from the other
using r.mapcalculator to check). I'm not sure what is going on with the red
channel (*.r). It might or might not be significant.

In other words, I *think* that either of your green or blue channels are
your imported DEM. You can do a few spot checks using d.what.raster to
verify this.

Michael Barton


On 11/11/04 3:25 AM, "lawrence moran" <L.J.Moran at newcastle.ac.uk> wrote:

> Hi,
>  
> Thanks to those who helped with my previous query- I'm now getting somewhere!
>  
> Next I'm trying to bring in some SRTM topographic data. I've used MacDEM to
> merge 4 degree squares and exported these as a tiff with world file. Using
> r.in.tiff, I get three bands (.r, .g, .b). However band .r displays as null
> values, .g and .b display as greyscale.
>  
> Any ideas what's going on?
>  
> Thanks,
>  
> Lawrence

____________________
C. Michael Barton, Professor of Anthropology
School of Human Evolution and Social Change
PO Box 872402
Arizona State University
Tempe, AZ  85287-2402
USA

Phone: 480-965-6262
Fax: 480-965-7671
www: <www.public.asu.edu/~cmbarton>