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[Tips] Screen Color Calibration for the Galaxy Nexus

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mumchristmas
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(Last edited by mumchristmas; 28th February 2012 at 08:42 AM.) Reason: More detail added
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Default [Tips] Screen Color Calibration for the Galaxy Nexus

After using the Galaxy Nexus for two weeks, I found the screen color of the new amoled+ is much better than the Nexus S, but still inaccuracy. I'm a part-time photographer who keen on the right Gamma, color accuracy and color temperature.

So I just finished some test with such things:
  1. Galaxy Nexus
  2. franco Kernel 18.5 nightly(with the ColorControl from Ezekeel)
  3. Voodoo Screen Test app
  4. x-rite i1 Display 2 color meter
  5. 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:
  1. Make sure you have a rom/mod with /init.d autorun function.

    Bye, stock rom...:P

  2. Make sure you have a kernel with ColorControl function.

    Such like Ezekeel, franco...Else? I don't know.

  3. 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.

  4. 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:
    Code:
    echo "-10 0 -10" > /sys/class/misc/colorcontrol/v1_offset
    
    echo "1820000000 1900000000 2000000000" > /sys/class/misc/colorcontrol/multiplier
    I choose "182 190 200" here, because the default value was about 200. Rising will increase the risk of LED Burn-in.

    And, don't forget the 7 zero!!!

  5. 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.
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heo_con184
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(Last edited by heo_con184; 28th February 2012 at 06:18 AM.)
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Thanks so much for the mod.

I'm willing to test your new calibration for the GNex color but how can I revert back to stock in case of problem ?

So I guess we can only use this modification at 50% of brightness ? If we change to auto, how could it be ?
 
mohitrocks
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Sorry for being a noob here, but this is compatible with any rom/kernel right? I'm currently running on AOKP Build 25 and Popcorn kernel 7.1

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mazubo
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(Last edited by imfloflo; 28th February 2012 at 07:20 AM.)
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Hi, and thank you for offering your expertise. I'm not confident in doing the above.... Can you offer a little bit more step by step?

I've played around with root explorer which I imagine is what is necessary to change these values.you lost me at the 2nd step.....

Also, is 50% necessary?

Thanks kindly,



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mumchristmas
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Quote:
Originally Posted by mazubo View Post
Hi, and thank you for offering your expertise. I'm not confident in doing the above.... Can you offer a little bit more step by step?

I've played around with root explorer which I imagine is what is necessary to change these values.you lost me at the 2nd step.....

Also, is 50% necessary?

Thanks kindly,



_______________________________
frAncO Kernel ;-P
Quote:
Originally Posted by mohitrocks View Post
Sorry for being a noob here, but this is compatible with any rom/kernel right? I'm currently running on AOKP Build 25 and Popcorn kernel 7.1

Thanks,
Mosh
Quote:
Originally Posted by heo_con184 View Post
Thanks so much for the mod.

I'm willing to test your new calibration for the GNex color but how can I revert back to stock in case of problem ?

So I guess we can only use this modification at 50% of brightness ? If we change to auto, how could it be ?
Step by step detail added. Thx for reading~
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siedkins
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Thanks for the guide!

Sent from my Galaxy Nexus using XDA App
LG G2 (802) (Vodafone UK)
ROM - Stock
-------------------------------------------
Samsung Galaxy Nexus GSM (Orange UK)
ROM - CM10.2
Kernel - franco.Kernel (nightly)
-------------------------------------------
HTC Desire (Orange UK)
Rooted using unrevoked / 4Ext Recovery / CM71.0 / CM7r2 HBoot / ManU 2.0.1 Kernel
-------------------------------------------
My Guide To Using ADB & Fastboot On OSX/Mac
 
fescen9
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You can change all of these settings from Franco's kernel updater program directly without modifying any files.
The OP's settings appear a little warm at first but I'm liking them so far...

Sent from my Galaxy Nexus using xda premium
 
firemountain
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Can you please add this file 900colorcontrol-b50
 
andrewlax120
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sooooo do i make a folder in system like this?

system/etc/init.d/900colorcontrol-b50 and then add that text above or??
 
dmmarck
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Instead of making that script, can we just input those numbers into the Color Control?

-10, 0, -10 for Gamma (RGB);
182, 190, 200 for Multiplier (RGB)

Right?
LG Nexus 5 - 16GB/Black - Unlocked, Rooted, TWRP, franco.Kernel
ASUS Nexus 7 (2013) - 16GB - Unlocked

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