#3110: i.colors.enhance or r.colors: add Gamma correction parameter to improve
brightness
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Reporter: neteler | Owner: grass-dev@…
Type: enhancement | Status: new
Priority: normal | Milestone: 7.2.0
Component: Imagery | Version: svn-
| releasebranch72
Keywords: i.colors.enhance, r.colors, gamma | CPU: Unspecified
Platform: Unspecified |
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Sometimes color composites of satellite data are very dark. A common
solution is "Gamma correction"
(https://en.wikipedia.org/wiki/Gamma_correction) which brightens an image
while keeping colors intact.
While I would like to see a gamma=... parameter in i.colors.enhance, I
guess that it needs to be added to r.colors.
Some code:
* https://github.com/imagico/gdal-py/blob/master/ls2rgb.py (uses numpy)
* r7436 brought some gamma support to r.in.png but it is not quite clear
to me what it does. At least it is in C.
Maybe it is not complicated to add that?
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Ticket URL: <https://trac.osgeo.org/grass/ticket/3110>
GRASS GIS <https://grass.osgeo.org>