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r.composite

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

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

Example:

r.composite red=name green=name blue=name output=name

grass.script.run_command("r.composite", red, green, blue, levels=32, level_red=None, level_green=None, level_blue=None, output, flags=None, overwrite=False, verbose=False, quiet=False, superquiet=False)

Example:

gs.run_command("r.composite", red="name", green="name", blue="name", output="name")

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
    Allowed values: 1-256
    Default: 32
level_red=integer
    Number of levels to be used for <red>
    Allowed values: 1-256
level_green=integer
    Number of levels to be used for <green>
    Allowed values: 1-256
level_blue=integer
    Number of levels to be used for <blue>
    Allowed values: 1-256
output=name [required]
    Name for output raster map
-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
--qq
    Very quiet module output
--ui
    Force launching GUI dialog

red : str, required
    Name of raster map to be used for <red>
    Used as: input, raster, name
green : str, required
    Name of raster map to be used for <green>
    Used as: input, raster, name
blue : str, required
    Name of raster map to be used for <blue>
    Used as: input, raster, name
levels : int, optional
    Number of levels to be used for each component
    Allowed values: 1-256
    Default: 32
level_red : int, optional
    Number of levels to be used for <red>
    Allowed values: 1-256
level_green : int, optional
    Number of levels to be used for <green>
    Allowed values: 1-256
level_blue : int, optional
    Number of levels to be used for <blue>
    Allowed values: 1-256
output : str, required
    Name for output raster map
    Used as: output, raster, name
flags : str, optional
    Allowed values: d, c
    d
        Dither
    c
        Use closest color
overwrite: bool, optional
    Allow output files to overwrite existing files
    Default: False
verbose: bool, optional
    Verbose module output
    Default: False
quiet: bool, optional
    Quiet module output
    Default: False
superquiet: bool, optional
    Very quiet module output
    Default: False

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

SOURCE CODE

Available at: r.composite source code (history)
Latest change: Friday Feb 07 19:16:09 2025 in commit a82a39f