NAME

       r.out.ppm  - Converts a GRASS raster map to a PPM image file.

KEYWORDS

       raster, export, output

SYNOPSIS

       r.out.ppm
       r.out.ppm --help
       r.out.ppm [-gh] input=name  [output=name]   [--overwrite]  [--help]  [--verbose]  [--quiet]  [--ui]

   Flags:
       -g
           Output greyscale instead of color

       -h
           Suppress printing of PPM header

       --overwrite
           Allow output files to overwrite existing files

       --help
           Print usage summary

       --verbose
           Verbose module output

       --quiet
           Quiet module output

       --ui
           Force launching GUI dialog

   Parameters:
       input=name [required]
           Name of input raster map

       output=name
           Name for new PPM file (use ’-’ for stdout)
           Default: <rasterfilename>.ppm

DESCRIPTION

       r.out.ppm  converts  a GRASS raster map into a PPM image at the pixel resolution of the CURRENTLY DEFINED
       REGION.  To get the resolution and region settings of the raster map, run:

       g.region -p raster=[mapname]

       before running r.out.ppm.

       By default the PPM file created is 24-bit color, rawbits storage.  You can  use  the  -g  flag  to  force
       r.out.ppm to output an 8-bit 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.

NOTES

       A few ppm file comments are written: the name of the GRASS raster map, 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.)

HINTS

       You can create a PNG image with NULL values represented by a transparent  background  by  using  the  PNG
       driver  with  GRASS_RENDER_TRANSPARENT set to TRUE.  Alternatively, you can use the pnmtopng program from
       netpbm to do this:
       r.out.ppm raster
       pnmtopng -transparent white raster.ppm > raster.png

SEE ALSO

        d.out.file, r.out.ascii, r.out.gdal, r.out.mpeg, r.out.png, r.out.ppm3

AUTHOR

       Bill Brown, UIUC

SOURCE CODE

       Available at: r.out.ppm source code (history)

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       © 2003-2019 GRASS Development Team, GRASS GIS 7.8.2 Reference Manual