r.colors.contrastbrightness - GRASS GIS manual

Note: This addon document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade your GRASS GIS installation, and read the current addon manual page.

NAME

r.colors.contrastbrightness - Change the contrast/brightness of a raster.

KEYWORDS

raster, imagery, contrast, brightness

SYNOPSIS

r.colors.contrastbrightness

r.colors.contrastbrightness --help

r.colors.contrastbrightness input=name output=name minimum=value maximum=value contrast=value brightness=value [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:

--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:

input=name [required]: Raster map to change the contrast of.
output=name [required]: Name for output raster map
minimum=value [required]: Minimum input/output data value
maximum=value [required]: Maximum input/output data value
contrast=value [required]: Contrast (gain, 8bit=>[1.0-3.0]; Default: 1.0
brightness=value [required]: Brightness (bias, 8bit=>[0.0-100.0]); Default: 0.0

DESCRIPTION
EXAMPLES
SEE ALSO
AUTHOR

DESCRIPTION

The r.colors.contrastbrightness module generates a contrasted version of the input raster map. The contrast is the gain of the affine transform, use values of 1.0-3.0 in case of an 8 bit image. The brightness is the bias of the affine transform, use values of 0.0-100.0 in case of an 8 bit image.

EXAMPLES

Contrast enhancement of an 8-bit raster band This does nothing to the image:

r.colors.contrastbrightness min=0.0 max=255.0 contrast=1.0 brightness=0.0 input=myinraster output=myoutraster

This does change the contrast of the image:

r.colors.contrastbrightness min=0.0 max=255.0 contrast=3.0 brightness=0.0 input=myinraster output=myoutraster

This does change the brightness of the image:

r.colors.contrastbrightness min=0.0 max=255.0 contrast=1.0 brightness=100.0 input=myinraster output=myoutraster

AUTHOR

Yann Chemin, JRC, Ispra, Italy

SOURCE CODE

Available at: r.colors.contrastbrightness source code (history)

Latest change: Mon Jun 28 07:54:09 2021 in commit: 1cfc0af029a35a5d6c7dae5ca7204d0eb85dbc55