d.rgb

NAME

d.rgb - Displays three user-specified raster map layers as red, green, and blue overlays in the active graphics frame.
(GRASS Display Program)

SYNOPSIS

d.rgb
d.rgb help
d.rgb [red=name] [green=name] [blue=name]

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.

WARNING: Maps that are using the "color wave" color table appear to be solid grey when using d.rgb. The average intensity of the colors being used is always 33%.

OPTIONS

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 uses 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, consider to run r.colors (greq.eq color table) on the selected satellite channels.

To write out the color composite to a R/G/B raster maps, use r.composite (three maps) or i.composite (single composite map).

AUTHOR

Glynn Clements

Last changed: $Date$