NAME

       r.composite   -  Combines  red,  green and blue raster maps into a single composite raster
       map.

KEYWORDS

       raster, composite, RGB

SYNOPSIS

       r.composite
       r.composite --help
       r.composite [-dc] red=name green=name  blue=name   [levels=integer]    [level_red=integer]
       [level_green=integer]     [level_blue=integer]    output=name    [--overwrite]    [--help]
       [--verbose]  [--quiet]  [--ui]

   Flags:
       -d
           Dither

       -c
           Use closest color

       --overwrite
           Allow output files to overwrite existing files

       --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>

       levels=integer
           Number of levels to be used for each component
           Options: 1-256
           Default: 32

       level_red=integer
           Number of levels to be used for <red>
           Options: 1-256

       level_green=integer
           Number of levels to be used for <green>
           Options: 1-256

       level_blue=integer
           Number of levels to be used for <blue>
           Options: 1-256

       output=name [required]
           Name for output raster map

DESCRIPTION

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

NOTES

       The  default  number of intensity levels for each component is 32, resulting in a total of
       32768 possible colors (equivalent to 15 bits per pixel). If significantly more levels than
       this  are used, not only will r.composite take longer to run, but displaying the resulting
       layer with d.rast will also be significantly slower.

       Floyd-Steinberg dithering is optionally used with the -d flag.

EXAMPLES

   RGB composite of three satellite bands
       Color composite of a LANDSAT scene (North Carolina sample dataset):
       g.region raster=lsat7_2002_10
       r.composite blue=lsat7_2002_10 green=lsat7_2002_20 red=lsat7_2002_30 \
                   output=lsat7_2002_rgb

   RGB composite with dithering
       Creating a composite RGB raster using 32 color levels per layer, with dithering:
       r.composite -d red=elevation.r green=elevation.g blue=elevation.b \
                   output=elev.composite

SEE ALSO

        d.rast, d.rgb, r.blend, r.colors, r.rgb

        Wikipedia Entry: Floyd-Steinberg dithering

AUTHOR

       Glynn Clements

       Last changed: $Date: 2014-12-28 16:42:58 +0100 (Sun, 28 Dec 2014) $

SOURCE CODE

       Available at: r.composite source code (history)

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       © 2003-2018 GRASS Development Team, GRASS GIS 7.4.0 Reference Manual