[xorg-xgamma] Xgamma and xrandr discrepancy
anrxc at sysphere.org
Sat Dec 21 08:14:38 PST 2013
Hello I have a small issue with xgamma for a very long time that nobody
could explain to me, so now I'd like to ask the developers.
To get decent colors on my workstation and external monitors I want to
apply gamma correction. For me these magic values do it "Gamma 0.75 0.65
0.60", I set them in xorg.conf for each monitor.
If it happens that an external monitor wasn't connected when I started X
I can attach it with xrandr. Well when I do that the colors on the
monitor are completely off. Even though xgamma reports "-> Red 0.750,
Green 0.650, Blue 0.600" when I check, the colors are simply wrong. I
have to kill X, start, and everything is back to normal. These forced
restarts partly defeat the hotplugging ideas in xrandr.
Here's what Xorg.0.log has to say:
> [ 44816.100] (II) intel(0): Using default gamma of (1.0, 1.0, 1.0) unless otherwise stated.
> [ 44816.101] (II) intel(0): Output VGA1 wants gamma correction (0.8, 0.6, 0.6)
Trying to correct colors my self, after using xrandr, isn't succesful.
xgamma doesn't produce good colors. I have also tried to set gamma with
xrandr, both when attaching the display or afterwords, i.e. by using
this switch --gamma 0.75:0.65:0.60 or --gamma 0.8:0.6:0.6. This produces
bad results as well. Colors are always wrong, always very washed out to
Nothing but an X restart does it for years, across 5 portable computers
and all forms and sizes of CRT and LCD monitors. Could anyone explain
Adrian C. (anrxc) | anrxc..sysphere.org | PGP ID: D20A0618
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