

R.OUT.PPM - Not yet a part of any official GRASS release.
	    This is the only documentation currently available.
	    No implied warranties... usual disclaimers... etc.

Usage:
 r.out.ppm [-qG] input=name [output=name]

Flags:
  -q   Run quietly
  -G   Output greyscale instead of color

Parameters:
   input   Raster file to be converted.
  output   Name for new PPM file. (use out=- for stdout)
           default: <rasterfilename>.ppm


This program converts a GRASS raster file to a PPM image file
at the pixel resolution of the CURRENTLY DEFINED REGION. 
e.g., to get the resolution of the raster map, do:
	g.region rast=[mapname]
before running r.out.ppm.

The PPM file created is 24bit color, rawbits storage by default.
Using -G, you may force r.out.ppm to use 8bit greyscale instead.
The greyscale conversion uses the NTSC conversion:
Y = .30*Red + .59*Green + .11*Blue

One pixel is written for each cell value, so if ew_res and ns_res
differ, the aspect ratio of the resulting image will be off.

NOTE: A few ppm file comments are written - the name of the GRASS
raster file, resolution, etc.  Although these are perfectly legal,
I've found one PD image utility that chokes on them, so if you need 
a commentless ppm file, use out=- > outfile.ppm. (When sending 
output to stdout, no comments are written.)

TODO: allow combination of 3 grass files to represent R, G, B components
      of ppm file?
***************************************************************************
Bill Brown				e-mail: brown@zorro.cecer.army.mil
USACERL - ECS				phone:  (217) 352-6511 ext 7676
PO Box 9005
Champaign, IL  61826-9005

See our visualization demo on the World Wide Web at:
http://www.cecer.army.mil/grass/viz/VIZ.html
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