1d.rgb(1) GRASS GIS User's Manual d.rgb(1)
2
3
4
6 d.rgb - Displays three user-specified raster maps as red, green, and
7 blue overlays in the active graphics frame.
8
10 display, graphics, raster, RGB
11
13 d.rgb
14 d.rgb --help
15 d.rgb [-n] red=name green=name blue=name [--help] [--verbose]
16 [--quiet] [--ui]
17
18 Flags:
19 -n
20 Make null cells opaque
21
22 --help
23 Print usage summary
24
25 --verbose
26 Verbose module output
27
28 --quiet
29 Quiet module output
30
31 --ui
32 Force launching GUI dialog
33
34 Parameters:
35 red=name [required]
36 Name of raster map to be used for <red>
37
38 green=name [required]
39 Name of raster map to be used for <green>
40
41 blue=name [required]
42 Name of raster map to be used for <blue>
43
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.
50
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.
57
58 If color quality of satellite image color composites seems to appear
59 poor, run i.colors.enhance on the selected satellite channels.
60
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
69
70 To write out the color composite to a combined R/G/B raster maps, use
71 r.composite.
72
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)
80
82 d.colortable, d.his, r.blend, r.mapcalc, r.colors, r.composite
83
85 Glynn Clements
86
88 Available at: d.rgb source code (history)
89
90 Accessed: Saturday Jan 21 21:14:12 2023
91
92 Main index | Display index | Topics index | Keywords index | Graphical
93 index | Full index
94
95 © 2003-2023 GRASS Development Team, GRASS GIS 8.2.1 Reference Manual
96
97
98
99GRASS 8.2.1 d.rgb(1)