1r.out.ppm(1) GRASS GIS User's Manual r.out.ppm(1)
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6 r.out.ppm - Converts a GRASS raster map to a PPM image file.
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9 raster, export, output
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12 r.out.ppm
13 r.out.ppm --help
14 r.out.ppm [-gh] input=name [output=name] [--overwrite] [--help]
15 [--verbose] [--quiet] [--ui]
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17 Flags:
18 -g
19 Output greyscale instead of color
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21 -h
22 Suppress printing of PPM header
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24 --overwrite
25 Allow output files to overwrite existing files
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27 --help
28 Print usage summary
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30 --verbose
31 Verbose module output
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33 --quiet
34 Quiet module output
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36 --ui
37 Force launching GUI dialog
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39 Parameters:
40 input=name [required]
41 Name of input raster map
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43 output=name
44 Name for new PPM file (use ’-’ for stdout)
45 Default: <rasterfilename>.ppm
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48 r.out.ppm converts a GRASS raster map into a PPM image at the pixel
49 resolution of the CURRENTLY DEFINED REGION. To get the resolution and
50 region settings of the raster map, run:
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52 g.region -p raster=[mapname]
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54 before running r.out.ppm.
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56 By default the PPM file created is 24-bit color, rawbits storage. You
57 can use the -g flag to force r.out.ppm to output an 8-bit greyscale in‐
58 stead. The greyscale conversion uses the NTSC conversion:
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60 Y = .30*Red + .59*Green + .11*Blue
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62 One pixel is written for each cell value, so if ew_res and ns_res dif‐
63 fer, the aspect ratio of the resulting image will be off.
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66 A few ppm file comments are written: the name of the GRASS raster map,
67 resolution, etc. Although these are perfectly legal, I’ve found one PD
68 image utility that chokes on them, so if you need a commentless PPM
69 file, use ’out=-Â >Â outfile.ppm’. (When sending output to stdout, no
70 comments are written.)
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73 You can create a PNG image with NULL values represented by a transpar‐
74 ent background by using the PNG driver with GRASS_RENDER_TRANSPARENT
75 set to TRUE. Alternatively, you can use the pnmtopng program from
76 netpbm to do this:
77 r.out.ppm raster
78 pnmtopng -transparent white raster.ppm > raster.png
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81 d.out.file, r.out.ascii, r.out.gdal, r.out.mpeg, r.out.png, r.out.ppm3
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84 Bill Brown, UIUC
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87 Available at: r.out.ppm source code (history)
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89 Accessed: Mon Jun 20 16:46:15 2022
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91 Main index | Raster index | Topics index | Keywords index | Graphical
92 index | Full index
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94 © 2003-2022 GRASS Development Team, GRASS GIS 8.2.0 Reference Manual
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98GRASS 8.2.0 r.out.ppm(1)