So I just finished some test with such things:
- Galaxy Nexus
- franco Kernel 18.5 nightly(with the ColorControl from Ezekeel)
- Voodoo Screen Test app
- x-rite i1 Display 2 color meter
- HCFR software
The test result was not so good...
- Average Gammar value is about 1.9, far from the ISO stand 2.2. So the color is just too bright (I'm not saying screen brightness).
- The shadow part (0-40% gray level) of 3 color curve were almost out of trim. In another words, incaauracy color balance.
- As the color unbalance. The color temperature is starting from lower than 5500K to 6500K, which the ISO stand is 6500K at any color level.
I also tested the ColorControl in franco Kernel. After the adjustments, Gammar value is still bad, but I save the (most part of) color balance & color temperature in the end.
The adjustments step by step:
- Make sure you have a rom/mod with /init.d autorun function.
Bye, stock rom...:P
- Make sure you have a kernel with ColorControl function.
Such like Ezekeel, franco...Else? I don't know.
- Set the screen brightness to 50%.
It's the mesurement "baseline". But why 50%?
Because, at this point the screen has a brightness about 120 Lux--also a ISO stand. So, it's very close to our desktop LCD.
- Make a new file as /etc/init.d/900colorcontrol-b50
Which could be done by Root Explorer or adb.
Inside the file, type such line:
echo "-10 0 -10" > /sys/class/misc/colorcontrol/v1_offset echo "1820000000 1900000000 2000000000" > /sys/class/misc/colorcontrol/multiplier
And, don't forget the 7 zero!!!
- Just reboot & enjoy the almost right color temperature.
It's (6500±300)K at any color level in my device. Not perfect, but much better indeed.
Done, that's all I can do for you.