[GRASS-user] RE: r.mapcalc on RGB composite
glynn at gclements.plus.com
Wed May 9 13:02:32 EDT 2007
Jarle Pedersen wrote:
> Regarding the earlier questions posed, I figured out the correct syntax
> for r.mapcalc. However, if anyone care to, I'd still like to know why this
> shift in coloration happens.
Because you haven't defined a colour table for the new map.
Try "r.colors RGB_water raster=RGB".
An alternative approach would be to use masking, e.g.:
r.mapcalc 'MASK = dem != 0'
r.resample in=RGB out=RGB_water
r.resample automatically copies the colours from the input map.
Glynn Clements <glynn at gclements.plus.com>
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