NAME

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

KEYWORDS

       display, graphics, raster, RGB

SYNOPSIS

       d.rgb
       d.rgb --help
       d.rgb [-n] red=name green=name blue=name  [--help]  [--verbose]  [--quiet]  [--ui]

   Flags:
       -n
           Make null cells opaque

       --help
           Print usage summary

       --verbose
           Verbose module output

       --quiet
           Quiet module output

       --ui
           Force launching GUI dialog

   Parameters:
       red=name [required]
           Name of raster map to be used for <red>

       green=name [required]
           Name of raster map to be used for <green>

       blue=name [required]
           Name of raster map to be used for <blue>

DESCRIPTION

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

NOTES

       d.rgb  does not attempt to quantize the combined image into a fixed number of colors. Nor does it have an
       option to generate a composite layer (see r.composite for that).  The image  and  raster  maps  will  not
       display properly if the graphics device does not have a reasonable sampling of the RGB color-space.

       If  color  quality  of satellite image color composites seems to appear poor, run i.colors.enhance on the
       selected satellite channels.

       An alternative is the assignment of grey color tables to each band with r.colors:
       r.info -r image.1
       min=0
       max=255
       r.colors map=image.1 color=grey
       r.colors map=image.2 rast=image.1
       r.colors map=image.3 rast=image.1

       To write out the color composite to a combined R/G/B raster maps, use r.composite.

EXAMPLE

       Visual color composite of a LANDSAT scene (North Carolina sample dataset):
       g.region raster=lsat7_2002_10 -p
       d.rgb blue=lsat7_2002_10 green=lsat7_2002_20 red=lsat7_2002_30
       Figure: Visual color composite of a LANDSAT scene (North Carolina sample dataset)

SEE ALSO

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

AUTHOR

       Glynn Clements

SOURCE CODE

       Available at: d.rgb source code (history)

       Accessed: Monday Apr 01 03:07:14 2024

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       © 2003-2024 GRASS Development Team, GRASS GIS 8.3.2 Reference Manual

GRASS 8.3.2                                                                                        d.rgb(1grass)