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

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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

Table of contents

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

SEE ALSO

r.colors, v.colors, r3.colors, r.cpt2grass, r.colors.matplotlib

AUTHOR

Yann Chemin, JRC, Ispra, Italy

SOURCE CODE

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

Latest change: Monday Jan 30 19:49:11 2023 in commit: 5fb6b1a969e72db28df78483d3360b15a17f0c68

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© 2003-2024 GRASS Development Team, GRASS GIS 8.3.3dev Reference Manual