[GRASS-user] r.mapcalc on RGB composite
mybigb at gmail.com
Wed May 9 10:19:55 EDT 2007
Hi again folks. Next noobie question:
I'm trying to use r.mapcalc to set the sea of some landsat imagery to
null-values in order for me to view my much nicer background. My workflow
was as follows:
1. r.composite -d -c red="b1" green="b4" blue="b7" levels=32 output="RGB"
2. r.mapcalc "RGB_water=if(dem=0,null(),RGB)"
This does not fill the water with null, rather keeps the original values
and distorts the colors to yellow/greenish output.
What am I missing?
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