1d.rgb(1)                    GRASS GIS User's Manual                   d.rgb(1)
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NAME

6       d.rgb   -  Displays three user-specified raster maps as red, green, and
7       blue overlays in the active graphics frame.
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KEYWORDS

10       display, graphics, raster, RGB
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SYNOPSIS

13       d.rgb
14       d.rgb --help
15       d.rgb  [-n]  red=name  green=name  blue=name    [--help]    [--verbose]
16       [--quiet]  [--ui]
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18   Flags:
19       -n
20           Make null cells opaque
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22       --help
23           Print usage summary
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25       --verbose
26           Verbose module output
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28       --quiet
29           Quiet module output
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31       --ui
32           Force launching GUI dialog
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34   Parameters:
35       red=name [required]
36           Name of raster map to be used for <red>
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38       green=name [required]
39           Name of raster map to be used for <green>
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41       blue=name [required]
42           Name of raster map to be used for <blue>
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DESCRIPTION

45       RGB  stands  for  red,  green,  and blue. d.rgb visually combines three
46       raster maps to form a color image. For each map, the corresponding com‐
47       ponent  from  the  layer’s color table is used (e.g. for the red layer,
48       the red component is used, and so on). In  general,  the  input  raster
49       maps should use a grey-scale color table.
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NOTES

52       d.rgb does not attempt to quantize the combined image into a fixed num‐
53       ber of colors. Nor does it have an option to generate a composite layer
54       (see r.composite for that).  The image and raster maps will not display
55       properly if the graphics device does not have a reasonable sampling  of
56       the RGB color-space.
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58       If  color  quality  of satellite image color composites seems to appear
59       poor, run i.colors.enhance on the selected satellite channels.
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61       An alternative is the assignment of grey color tables to each band with
62       r.colors:
63       r.info -r image.1
64       min=0
65       max=255
66       r.colors map=image.1 color=grey
67       r.colors map=image.2 rast=image.1
68       r.colors map=image.3 rast=image.1
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70       To  write  out the color composite to a combined R/G/B raster maps, use
71       r.composite.
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EXAMPLE

74       Visual color composite  of  a  LANDSAT  scene  (North  Carolina  sample
75       dataset):
76       g.region raster=lsat7_2002_10 -p
77       d.rgb blue=lsat7_2002_10 green=lsat7_2002_20 red=lsat7_2002_30
78       Figure:  Visual color composite of a LANDSAT scene (North Carolina sam‐
79       ple dataset)
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SEE ALSO

82        d.colortable, d.his, r.blend, r.mapcalc, r.colors, r.composite
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AUTHOR

85       Glynn Clements
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SOURCE CODE

88       Available at: d.rgb source code (history)
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90       Main index | Display index | Topics index | Keywords index |  Graphical
91       index | Full index
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93       © 2003-2020 GRASS Development Team, GRASS GIS 7.8.5 Reference Manual
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97GRASS 7.8.5                                                           d.rgb(1)