r.colors.contrastbrightness - GRASS GIS manual

NAME

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

KEYWORDS

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)