NAME

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

KEYWORDS

       display, raster, RGB

SYNOPSIS

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

   Flags:
       -o
           Overlay (non-null values only)

       -x
           Don't add to list of commands in monitor

       --verbose
           Verbose module output

       --quiet
           Quiet module output

   Parameters:
       red=name
           Name of raster map to be used for 'red'

       green=name
           Name of raster map to be used for 'green'

       blue=name
           Name of raster map to be used for 'blue'

DESCRIPTION

       RGB stands for red, green, and blue. This program visually combines three raster map  layers  to  form  a
       color  image.  For each layer, 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  layers  should  use  a  grey-scale
       color table.

OPTIONS

   Flags:
       -o
              Overlay  the  resulting raster map layer onto whatever is already displayed in the active graphics
              frame. Any no-data areas in any of the named raster maps will seem  transparent,  and  reveal  the
              underlying  image  previously  displayed  in the graphics frame. If the -o flag is set, only cells
              containing non-null values will be displayed from the overlaid raster map. All other areas  (i.e.,
              the  portions  of  the  overlaid  map  that contain null values) will leave the underlying display
              untouched.

   Parameters:
       red=name
              Name of raster map layer to be used for RED component.

       green=name
              Name of raster map layer to be used for GREEN component.

       blue=name
              Name of raster map layer to be used for BLUE component.

NOTES

       This is a new version of d.rgb, which sends the data to the graphics monitor in  true-color  RGB  format.
       Unlike  the  previous  version, it 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.  The image and raster map layers  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 r.colors on the selected
       satellite channels.

       Example:
       r.info -r image.1
       min=0
       max=255
       r.colors map=image.1 color=rules << EOF
       0 black
       255 white
       EOF
       r.colors map=image.2 rast=image.1
       r.colors map=image.3 rast=image.1

       Note: Future GRASS versions may do this for you automatically.
       To write out the color composite to a R/G/B raster maps, use r.composite.

SEE ALSO

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

AUTHOR

       Glynn Clements

       Last changed: $Date: 2011-11-08 03:29:50 -0800 (Tue, 08 Nov 2011) $

       Full index

       © 2003-2013 GRASS Development Team

GRASS 6.4.3                                                                                        d.rgb(1grass)