1d.rgb(1) Grass User's Manual d.rgb(1)
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6 d.rgb - Displays three user-specified raster map layers as red, green,
7 and blue overlays in the active graphics frame.
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10 display
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13 d.rgb
14 d.rgb help
15 d.rgb [-ox] red=name green=name blue=name [--verbose] [--quiet]
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17 Flags:
18 -o
19 Overlay (non-null values only)
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21 -x
22 Don't add to list of commands in monitor
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24 --verbose
25 Verbose module output
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27 --quiet
28 Quiet module output
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30 Parameters:
31 red=name
32 Name of raster map to be used for
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34 green=name
35 Name of raster map to be used for
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37 blue=name
38 Name of raster map to be used for
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41 RGB stands for red, green, and blue. This program visually combines
42 three raster map layers to form a color image. For each layer, the cor‐
43 responding component from the layer's color table is used (e.g. for the
44 red layer, the red component is used, and so on). In general, the lay‐
45 ers should use a grey-scale color table.
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48 Flags:
49 -o
50 Overlay the resulting raster map layer onto whatever is already
51 displayed in the active graphics frame. Any no-data areas in any
52 of the named raster maps will seem transparent, and reveal the
53 underlying image previously displayed in the graphics frame. If
54 the -o flag is set, only cells containing non-null values will
55 be displayed from the overlaid raster map. All other areas
56 (i.e., the portions of the overlaid map that contain null val‐
57 ues) will leave the underlying display untouched.
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59 Parameters:
60 red=name
61 Name of raster map layer to be used for RED component.
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63 green=name
64 Name of raster map layer to be used for GREEN component.
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66 blue=name
67 Name of raster map layer to be used for BLUE component.
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70 This is a new version of d.rgb, which sends the data to the graphics
71 monitor in true-color RGB format. Unlike the previous version, it does
72 not attempt to quantize the combined image into a fixed number of col‐
73 ors. Nor does it have an option to generate a composite layer. The
74 image and raster map layers will not display properly if the graphics
75 device does not have a reasonable sampling of the RGB color-space.
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77 If color quality of satellite image color composites seems to appear
78 poor, run r.colors on the selected satellite channels.
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80 Example:
81 r.info -r image.1
82 min=0
83 max=255
84 r.colors map=image.1 color=rules << EOF
85 0 black
86 255 white
87 EOF
88 r.colors map=image.2 rast=image.1
89 r.colors map=image.3 rast=image.1
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91 Note: Future GRASS versions may do this for you automatically.
92 To write out the color composite to a R/G/B raster maps, use r.compos‐
93 ite.
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96 d.colors
97 d.colortable
98 d.his
99 r.blend
100 r.mapcalc
101 r.colors
102 r.composite
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105 Glynn Clements
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107 Last changed: $Date: 2005-03-01 21:15:12 +0100 (Tue, 01 Mar 2005) $
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109 Full index
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111 © 2003-2008 GRASS Development Team
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115GRASS 6.3.0 d.rgb(1)