1r.out.ppm(1)                  Grass User's Manual                 r.out.ppm(1)
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NAME

6       r.out.ppm   -  Converts  a GRASS raster file to a PPM image file at the
7       pixel resolution of the CURRENTLY DEFINED REGION.
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KEYWORDS

10       raster
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SYNOPSIS

13       r.out.ppm
14       r.out.ppm help
15       r.out.ppm [-qG] input=string  [output=string]
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17   Flags:
18       -q  Run quietly
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20       -G  Output greyscale instead of color
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22   Parameters:
23       input=string
24           Raster input map
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26       output=string
27           Name for new PPM file. (use out=- for stdout) Default: .ppm
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DESCRIPTION

30       r.out.ppm converts a GRASS raster file into a PPM image  at  the  pixel
31       resolution  of the CURRENTLY DEFINED REGION.  To get the resolution and
32       region settings of the raster map, run:
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35       g.region -p rast=[mapname]
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38       before running r.out.ppm.
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40       By default the PPM file created is 24-bit color, rawbits storage.   You
41       can  use  the  -G  flag to force r.out.ppm to output an 8-bit greyscale
42       instead.  The greyscale conversion uses the NTSC conversion:
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45       Y = .30*Red + .59*Green + .11*Blue
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48       One pixel is written for each cell value, so if ew_res and ns_res  dif‐
49       fer, the aspect ratio of the resulting image will be off.
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NOTES

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

59       You  can create a PNG image with NULL values represented by a transpar‐
60       ent background by using the PNG driver with  GRASS_TRANSPARENT  set  to
61       TRUE.   Alternatively,  you can use the pnmtopng program from netpbm to
62       do this:
63       r.out.ppm raster
64       pnmtopng -transparent white raster.ppm > raster.png
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SEE ALSO

68       d.out.png
69       r.out.ascii
70       r.out.mpeg
71       r.out.png
72       r.out.ppm3
73       r.out.tiff
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AUTHOR

76       Bill Brown, UIUC
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78       Last changed: $Date: 2007/01/28 22:18:17 $
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80       Full index
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84GRASS 6.2.2                                                       r.out.ppm(1)
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