GNOME Bugzilla – Bug 516366
monitor calibration
Last modified: 2013-04-19 13:34:43 UTC
One thing I'm really lacking on my GNOME desktop is the ability to configure my monitor settings. On a desktop session, this isn't a problem as the monitor itself has the necessary configuration abilities. On a laptop, however, there are no such things and you are stuck with whatever behaviour the screen exhibits by default. On other systems, the role of configuring your monitor falls on the graphics subsystem. X has this ability through the XF86VidTune extension. So what is needed is a decent GUI to manipulate it. The system doesn't need to be a complete colour calibration system, just the basic brightness, contrast and black level. Some might also like to tweak the gamma.
Created attachment 105201 [details] monadjust.glade
Created attachment 105202 [details] monadjust.py
Created attachment 105203 [details] monadjust_set_lut.c
Attached is a basic implementation of said feature. The Python file is the GUI and the one doing the necessary calculations. The C file handles calling the XF86VidTune extension (as Python has no support for it). This is a very basic version and needs things like GConf support and automatic screen configuration at login, but it shows that an application for this can easily be done.
Any functionality like that would have to be integrated with the display capplet (which is currently in the process of being rewritten, so I'm not sure it's a good idea to embark on this quest right now).
Isn't that a perfect time for it then? :) But yes, you're right. The settings are per monitor so it would need to be in a tool that is RandR aware.
Unless I'm mistaken, this is already solved by the color management integrated in GNOME 3.2. Richard?
Yup, this covers ICC profiles for each output, but doesn't actually have the capacity to do such crude changes as "contrast" and "brightness". It could be easily added, but I think the UI might be cumbersome, and the display is going to be have an even worse color match than calibrated. What's the use case of changing the output contrast and brightness LUTs?
The use case is defeating this idiotic practice of overly bright monitors that look good on the show floor but are completely unusable in a dimly lit room. Reducing the backlight level isn't a sufficient workaround for some panels. From what I've seen, this practice seems to be reduced with modern LED ones, but the use case might still be valid for some machines.
You can adjust the brightness through the control center already. Changing the contrast and black level seems like an advanced thing that should probably be provided by a separate tool.