yashsingh1/xdaforums huggingface dataset:
[Nexus 5 Themes and Apps] yorici:
I tried to create a mathematical connection between the white point and the registervalues. At first I found this to be true just for the registervalues:

The output of this should be viewed as the targeted result for gamma 2,2. With 255, that is 186.

RGB-186 is the same color used in the DisplayTesterApp for the gamma images. That color should then be matched with the background, and the device 'should be calibrated'. (Just works for 1/2 values)

(Later I found the same formula in a scientific document. The only difference being that 255 is described at the difference between black and white.)

The problem I discovered is that because the output is a single number, gamma only gets tested for 1/2 values. So I had to change some things around:

Then I realised that the white point runs from 0 to 63 and that 32 was

almost

at the middle. So I replaced 0,5 with (64-WP)/64, creating this formula. I did some research and found out that LG had set the white point at 32 instead of 31 for the sake of colour temperature. I know the middle is 31, but in this formula, as seen in the attachments, you have to take 32:

(64-32)/64 => Perfectly fine 0,5

(63-31)/63 => Not 0,5

(So you fill in WP, but you add 1. I didn't want to overcomplicate things already:P So you could change it to (64-WP-1)/64)

Now this works perfectly fine for WP=31, but I if you change the WP to 35 (=> (64-36)/64=>) and the output becomes 175. This is a great value, as this is the value that gets most affected by registervalue 11. This is fun and may work out for registervalue 11, but it gets me strange inputs for registervalue 14(WP=59).

So I need to change stuff around.

The one thing I certainly know is this from the following experiment:

Take a gamma image with a rectangle that is RGB-175, but with the background (0;255).

Then change the WP to 20 (or 19, doesn't matter for this experiment)

Try to match registervalue 11 with the rectangle

Change the WP to 60

Try to match it again

The difference between the registervalues is around 92

This is a linearity between the white point and the registervalues I have found to be true for multiple devices and multiple registervalues.

Reg11(X)*WP20 = Reg11(X+90)*WP60 = Output Y

It should be noted that for registervalues 1 to 12, the input should be seen as (255-Input). This gives a natural curve instead of the V-shaped curve.

This is also true for our previous noted equation.

(255 - Reg11(X)) * WP20 = (255 - Reg11(X - 90)) * WP60 = Output Y

(Note the X+90 went to X-90)

So there are a few things we know right now:

Our formula must be of the form: 255 * (FORMULA)^(1/2,2)

X must be changed in such a way that this is true: (255 - Reg11(X)) * WP20 = (255 - Reg11(X - 90)) * WP60 = Output Y

Due to device characteristics there should be an offset within FORMULA

For white point 31, the output should be 175 for registervalue 11

Lend a hand? ;P

If you don't understand some part of my explanation, please ask a question. It's a complicated proces and there is probably some things I missed explaining.
[Nexus 5 Themes and Apps] Tzfardaya:
and, after all this math, yorici and I determined that the wp might not actually be the "white" point,. but rather the midpoint...as you alter the value, you compress or stretch the highlights/shadows allowing for more details in the "stretched" range...

If you have/use photoshop, it might be similar to the midpoint slider in the levels adjustment...

(sorry, can't recall the exact heading... but hopefully my explanation is enough)

I know yorici has all sorts of documentation supporting his theory, but he forgot to look at the other end of the scale... he's been looking only at the "white" 255/255/255 and near whites... he forgot (or didn't think) to check the "black" 0/0/0 and near...

I'm sure next time yorici's here he can elaborate further...
[Nexus 5 Themes and Apps] yorici:
Been a while now. In the mean time I got a colorimeter and got the tests working.

Uploading two files here: One is WP=32, other WP=20. I can't indicate what the white point does yet.

You will need HCFR 3.0.4.0 to open up the files. (Files contains 256 RGB values, HCFR 3.0.4.0 supports it, kinda)
[Nexus 5 Themes and Apps] k20-:
Guys, where do I find yorici_v3 profile? Or anyone know of existing gamma 2.2 and 2.4 profiles?
[Nexus 5 Themes and Apps] Tzfardaya:
vomer keeps a collection of the "published" colour profiles in his signature....
[Nexus 5 Themes and Apps] GUGUITOMTG4:
yorici_v3
[Nexus 5 Themes and Apps] njiki11:
Is there anyway to set to boot. I'm on 1.0.11 and I've had to manually set the values every time I boot.
[Nexus 5 Themes and Apps] yorici:
First page, right corner. But better get FKU, Nexus Display Control, FauxClock or Kcontrol, because profiles ;)
[Nexus 5 Themes and Apps] njiki11:
Does this not work with Franco because it keeps reverting. And which of those apps do the thing where you put individual values like in this app since it seems like franco isn't working.
[Nexus 5 Themes and Apps] yorici:
You have to wait until the profile gets applied after boot (1/2 min). Then screen on/off.

Fku will support individual values soon, Kcontrol does already but with sliders which is really annoying.
[Nexus 5 Themes and Apps] andybfmv96:
I'm so confused. This is too advanced for me. Is there a definite setting I should be using?
[Nexus 5 Themes and Apps] Tzfardaya:
Probably just the stock settings then....
[Nexus 5 Themes and Apps] andybfmv96:
Well I know what gamma of my screen is and I'd love to fix the horrible color. Is there a database of ideal settings I could use? Or maybe presets I can use

(Franco kernel)
[Nexus 5 Themes and Apps] Rxpert:
Franco's kernel updater app has a list of preloaded profiles
[Nexus 5 Themes and Apps] yorici:
How do you know what the gamma of your screen is?
[Nexus 5 Themes and Apps] william84:
-Download Display Tester from PlayStore

-Select Gamma Detection in Display Tester

-The colored bar wich blends in with the backgrond (optional: test with different brightness values) has your gamma value
[Nexus 5 Themes and Apps] Tzfardaya:
Display tester only show the gamma at one point of the screen's range... For the most part we've only been using it to categorize the stock display settings.... So one point out of 256 for each colour...

There seem to be two displays... One with a stock game of 1.8 in the greyscale and the second with 2-2.2 in the greyscale... Which is yours? Using the stock color settings.
[Nexus 5 Themes and Apps] william84:
My screen has a stock greyscale value of 1.8
[Nexus 5 Themes and Apps] Tzfardaya:
Okay, try mag01, origin, fluidification_v4....
[Nexus 5 Themes and Apps] yorici:
The point is, the Display Tester App is flawed:

Although Display Tester App (and more apps alike) claim to test gamma, their results are biased . The principle the Display Tester App relies on is the following:

You create a background with a grid. The grid is composed of RGB (255,255,255) and RGB (0,0,0). This is the same as 0% and 100% gray. Because the eye can’t see individual pixels, the grid blends to a half tone: 50% gray. If you place a 50% gray block on the background, they should match. Up till this part, everything is correct.

There is one problem: The Display Tester App only tests 50% gray. 50% gray results in RGB (186,186,186). So basically, you are only testing only one RGB value out of 256.

To make this even more fun: The Display Tester App also messed up the background… While it should be a perfect grid of 0 and 255, it actually goes from 0 to 8 and 247 to 255. No, this is not better, it only is more biased. You can’t rely on RGB (1 to 254) as they are not calibrated yet.

If you have used the app, you may have noticed that changing the viewing angle, changes the outcome. The outcome is also dependent on ambient lighting, if the screen has been warmed up for 30 minutes, your eyes, brightness.

With so many variables you can’t believe this app will produce any reliable result… Even if it did, it would only count for RGB (186).

My advice: Do not rely on the Display Tester App or any other app that claims to be able to measure your gamma!

What can you use then? Only a tool like a colorimeter. I'm sorry if I disappoint you with this truth.

Notes:

- 50% gray = 0.5^2.2 * 255 = 186 (It’s not 127/128 due to gamma correction)

- You can see for yourself that the app is biased: Change value 9 (any color) to 255. Open the app: no real difference right? The 2.2 box will remain the same and the background too, while if you look at photographs there is noticeable something wrong! This can’t be right, can it?

(I know Tzfardaya already replied to you, but I wanted to explain it more detailed;))
[Nexus 5 Themes and Apps] william84:
Thnx for the extra info
[Nexus 5 Themes and Apps] epithetic:
Not sure if it's of any help but here are some HCFR measurements of my display for the yorici3, faux123, mag01 and stock settings (which are pretty much the only viable profiles I've seen). Faux123 in particular has an impressively well calibrated gamma for my screen (2.18 average). Colour balance is similar to stock (slightly off, comparatively best on mag01) on all of the above which is sad.

On the other hand, profiles attempting to balance the colours (like vomer3 or TJKV) come close(r) to equalising green and blues but ignore reds (making the disparity look even more extreme), and generally have gamma all over the place.

I've tried looking at some profiles myself but haven't really figured out much beyond the basics. Hope this helps, and if anyone wants/needs some measurements be sure to let me know! :)
[Nexus 5 Themes and Apps] yorici:
I have written a FAQ/guide/explanation on the values that is going to air soon. Then you can make your own profile! I want to post it in Orig Dev, so I'm waiting on response of the LG team mods. I had planned to release it today, but I need to get the response first.
[Nexus 5 Themes and Apps] yorici:
I posted my thread:)

Nexus 5: All color related (FAQ, Calibration Guide, Development)
[Nexus 5 Themes and Apps] mitchellvii:
Is there any way for non Nexus kernels to achieve this? I run a Tab 8.4 Pro and would LOVE to be able to dial down the gamma and get blacker blacks.
[Nexus 5 Themes and Apps] yorici:
This is very device specific. This won't work for you. I doubt your device has a similar thing. But perhaps there is. Google is your friend I would say;)
[Nexus 5 Themes and Apps] mitchellvii:
Unless the Nexus actually possesses different hardware than the Tab Pro line it should be possible to port this over in a Tab Pro kernel.
[Nexus 5 Themes and Apps] yorici:
Not a dev, so I don't know. Maybe myfluxi can help you with that;) Do want to note that all the profiles currently existing will not result in anything good on another device. Especially if it's an AMOLED that has a bigger gamut. Two completely different displays..
[Nexus 5 Themes and Apps] mitchellvii:
Thanks yeah not a dev either. The Tab Pro 8.4 has a super led screen with 2560 x 1660 resolution. Not amoled.
[Nexus 5 Themes and Apps] yorici:
That does mean you have another display installed. So any profile should be reprofiled, bc they won't make sense for your screen. Please let me know if you can get something going. I can help you guys with the inner workings of the parameters.
[Nexus 5 Themes and Apps] mitchellvii:
Thanks. I believe the first step is to find out if non Nexus phones have the parameters available in their kernel to turn this on. I am assuming they must since something is clearly setting the current gamma levels.
[Nexus 5 Themes and Apps] Asheque:
Explain

Can someone please mind telling me what this actually do :( ? I tried using it but I don't understand what it is I am doing.
[Nexus 5 Themes and Apps] Tzfardaya:
The purpose of this app is to help calibrate the colour levels displayed by our phones...

Some of us prefer properly calibrated devices (sRGB colourspace or another standard) some like to play with the colours to get what they think looks best..

Originally the purpose was to determine what the various values affected, to an extent it still is..

[MENTION=4809179]yorici[/MENTION], you're more knowledgeable than I in this regard...
[Nexus 5 Themes and Apps] Asheque:
I see. But how do you know which color needs adjustment? I am using neon dark theme. Any suggestion ? Does adding more depth to color consume more battery ?
[Nexus 5 Themes and Apps] Tzfardaya:
The only way to know for certain which colours need adjusting and how much is using a device like a colorimeter... Others exist (spectrometer for instance) but the colorimeter is usually the least expensive (and least accurate).

Anything else is just flavouring to personal tastes...

[MENTION=4809179]yorici[/MENTION] has a thread here that answers most questions about colour calibration on the n5... This thread hosts one of the apps yorici used to learn about calibration himself.
[Nexus 5 Themes and Apps] Asheque:
Sweet. Thank you for taking time to explain it to me. I will check it out. But by doing this, are we looking at a big difference? I browse a lot of photos and surf the web a lot and when I want better quality lol I just increase the brightness and looks pretty good on N5 though I know it is not the same thing. Still thank you very much sir, this gamma reverse is uber popular so must be something good if done rite. I will give it a shot.
[Nexus 5 Themes and Apps] Tzfardaya:
Out of the box, the n5 is pretty close to the sRGB colourspace. What the n5 lacks is contrast and so most colours look "washed out", reducing the brightness would actually help with deeper blacks :P. But that's not always possible, depending on ambient light.

Problem is that most people have become so used to super saturated colours (check out pretty much any Samsung phone) and think that a properly calibrated screen looks "blah"

If you've ever been to a TV shop that sells a TV calibration service, they usually have a "calibrated" and "non-calibrated" TV on display...

The non-calibrated has really punchy colours, overly bright bright, and the calibrated has more realistic colours, slightly more muted bright, etc etc..

The purpose of calibration is to get the display to show colours as close to real world as possible.. (ie, take a properly exposed photograph of something, then display that photograph and compare the image on the screen to the object captured in the image and have them match exactly)
[Nexus 5 Themes and Apps] Asheque:
Mind-Blown haha. Guess there is more to my N5 then i already know. Probably not the right place to ask this, but whats your average battery life and what sort of user are you? ( like do you fiddle around with your phone every 10-15 min even though u know you got no new notifications, turn on the screen often just to check time when you dont really need to, text a alot, surf the web)
[Nexus 5 Themes and Apps] Tzfardaya:
BT is always on, Pebble smart watch clones all my notifications so I don't need to fiddle with it to check. I abuse my phone.. Usually 2-3 hrs of screen on time over 6-8 hours battery... (yes, I'm charging my phone by 1pm most weekdays usually between 20-30% remaining)

But, a large part of my drain is radio.. At work I'm constantly in and out of office towers with variable signal... One tower will get full bars lte, yet the one across the street drops to 3g to maintain data connectivity, most elevators are data dead zones for me... So my phone spends a lot of power just trying to find signal.

That being said, I'm constantly on my phone with xda, news articles, irc, hangouts (sms, MMS, and gtalk)... Probably the only thing I don't use my phone for is phone calls...
[Nexus 5 Themes and Apps] Asheque:
lol k so its not just me, Because I hear of people getting 2 days easily with their phones (not N5) but crappy phone haha. I was using AOSB rom for a while OCed to 2.5 GHz using elemantalX kernel and would barely make it to 7-8 hrs. Just switched to AICP rom a day back and loving it. What is this Radio thingy? Correct me if I am wrong but I tried out the Android L preview and on that it said that Google or LG has disabled the Radio to increase battery life.
[Nexus 5 Themes and Apps] Tzfardaya:
Radio is what your phone uses to connect to cellular networks for voice and data (when they talk about edge, hdspa, 3g, 4g, lte, that's all radios) to connect to your wifi network, that's a second radio, BT uses a third radio, and nfc a fourth (short range)

In my previous post I was talking about the data radios.. 3g and lte mostly..

When I'm not at home I have wifi off, at work I turn the "scanning always available" option off (disables the wifi radio entirely)
[Nexus 5 Themes and Apps] Asheque:
Cool..Battery life dont matter when its such an awesome phone..Absolutely love it, cant get any better than this for the price. Though upsetting price dropped a lot, can get 32Gb now for the price of 16Gb I paid. Also was my 1st nexus device ever and really looking forward to next one but no more Nexus gonna be released anymore :( haha howz the weather in calgary? Are there lot of jobs down there?
[Nexus 5 Themes and Apps] Tzfardaya:
Right now the whole city smells like a campfire... All the smoke from bc forest fires being blown our way..

We're one of the few places in Canada with more jobs than people right now..

You're thinking that there's no more Nexus because Google has announced the Android silver program? Google has said that the silver program is not replacing the Nexus system...

here's an article about it
[Nexus 5 Themes and Apps] 93foxgt:
What city? Maybe I should move there to find work [emoji1]
[Nexus 5 Themes and Apps] Tzfardaya:
... Really? You need to ask?

It's not like it's in my profile, or even in the question I answered in my previous post...
[Nexus 5 Themes and Apps] 93foxgt:
Touché. Didn't think to click on profile.
[Nexus 5 Themes and Apps] Asheque:
haha sweet. But is it cold down there? Im in ON now, after im done school I am thinking of moving there for jobs. I heard there are not many girls lol.. is that true?
[Nexus 5 Themes and Apps] Tzfardaya:
Warmer winters than Ontario I'm told... When you guys deep freeze, it lasts... Here it's a week, tops (usually) before it warms back up... Gotta love Chinook winds..

As to girls, depends where you work... Lots downtown, not so many in the industrial parks... But yeah, Calgary is an oil city, and oil is still mostly a man's game...
[Nexus 5 Themes and Apps] Jeeza:
Deleted
[Nexus 5 Themes and Apps] enzo-ita:
Hi,

I have read some of the posts. Not the whole thread!!!

I have a question which may be silly and I apologyze in advance.

I purchased a THL 5000 and the display is simply horrible compared to the Galaxy S3 I own. Colors are washed out and there is no contrast.

I would like to tweak my phone but I have not been able to understand if this app can be used with that phone and/or if there is something I can do to make it working on the THL 5000.

Also if someone knows about something I could do to improve the appearance of the display, please tell me about.

Thanks in advance for your answers.

Ciao from Italy
[Nexus 5 Themes and Apps] Tzfardaya:
This app is specific to the n5, you should check the forums for your device to see if they have any color control apps yet...
[Nexus 5 Themes and Apps] yorici:
Tsss not even bothering reading all 1091 pages? ;)

This is Nexus 5 only. Sorry. Can't help ya with a S3
[Nexus 5 Themes and Apps] yorici:
Delete.. Xda app grmbl
[Nexus 5 Themes and Apps] Tzfardaya:
Speaking of not reading posts.. :P
[Nexus 5 Themes and Apps] ho0o0o11111:
Hello

I searched but didn't find an answer.

Is it possible to use this app/mod to make screen color inverted? (i.e. White background to black, for reading)

(by faux123 or Franco's kernel)

Thanks. :laugh:
[Nexus 5 Themes and Apps] Tzfardaya:
No, this is a calibration app...

I guess you could try, but it would seriously mess with your display...
[Nexus 5 Themes and Apps] fchowd0696:
Is it possible to have this app running on the new L preview?
[Nexus 5 Themes and Apps] Tylog:
No. Google Stock kernel alow no gamma modifications
[Nexus 5 Themes and Apps] fchowd0696:
What about simple rgb corrections? I love the new L preview but I can't stand the yellow tint on my phone.

Is there a custom kernel that supports L and gamma/rgb corrections?
[Nexus 5 Themes and Apps] Tylog:
There is no Kernel because there are no sources for the latest build, i hate the yellow tint too but solong no source we need zu life with it, the source drop maybe before 11/03 release.
[Nexus 5 Themes and Apps] fchowd0696:
I figured but I heard that there are some preexisting kernels that just happen to work with L like elementalx.
[Nexus 5 Themes and Apps] Tylog:
Belive me, for the latest L Build no Custom Kernel work. Only for the older previous, not for the latest.

No source, no Custom Kernel
[Nexus 5 Themes and Apps] fchowd0696:
Roger that. That sucks. I guess patience is a virtue in this regard.
[Nexus 5 Themes and Apps] nokiagye:
Hi I need to add gamma control on nexus 5x can you help me? Thanks in advance.
[Nexus 5 Themes and Apps] ChazzMatt:
We still need some setting to crush the blacks just a little more. I'm not talking about lowering brightness, I mean making the blacks look blacker. In previous version of Franco app (FKU), he had an OMAP interface that worked very well to crush the blacks on a variable scale to your satisfaction so the display looked very crisp.

In the broadcast industry when setting up a video monitor, besides accurate colors, we also want blacks to be at an accurate level.

If blacks are too high, that makes the video look "washed out".

We use a vector scope, we use color bars to check color accuracy. The points should hit correctly or else your colors are WRONG.

but also on this color bars, see the gradient levels of black on the lower right?

When a display/monitor is set up correctly, you should barely be able to see the differences. If you see no difference (it all looks one shade of black), the blacks are crushed TOO much. But if you see a great difference, then the blacks are too high. Looking at this picture on my Nexus 5, I can still see TOO MUCH DIFFERENCE in the gradient blacks on the lower right corner of this color bars representation.

This is why our displays look "washed out".
[Nexus 5 Themes and Apps] Batfink33:
A quick question, why do LG not properly calibrate their screens and release them in such a mess?
[Nexus 5 Themes and Apps] ChazzMatt:
Not just LG. Samsung Galaxy Nexus displays were also famously not accurate out of the box.

_______

Sent from my Nexus 5 (LG-D820)
[Nexus 5 Themes and Apps] Ok_Kaleidoscope5109:
Its more Google than anything. It takes time and money to develop a calibration process that suits all the phones accounting for screen variation. You can see that some like Apple try very hard to get this down. Even HTC does a good job.
[Nexus 5 Themes and Apps] Batfink33:
I find my wife's 5s display fairly washed out. Not impressed with it at all.
[Nexus 5 Themes and Apps] Ok_Kaleidoscope5109:
Eh, it's setup at Gamma 2.2 and it's calibrated pretty well. Ok, sorry I meant the 5, not the 5s, but Anand goes into detail here: http://www.anandtech.com/show/6330/the-iphone-5-review

It's washed out if you compare to a Galaxy S4 or an AMOLED screen, but in general it's pretty accurate. When I calibrated my Nexus 4 (which is washed out as hell btw), the finished result looked close to an iPhone 5.

As for the Nexus 5, it's a bit lower on the Gamma side out of the box. ~ Gamma 2.0 or so I believe.
[Nexus 5 Themes and Apps] TrainNanpaMaster:
This thread should have WAY more

interest and attention than it does. The color on this phone is so crap compared to other phones. I commend the developers for bringing this app to us.

On a side note, anyone else experiencing the color calibration settings randomly resetting when when the phone it's locked, than unlocked short while later?

Sent from my magical prancing unicorn.
[Nexus 5 Themes and Apps] tehdef:
Apple buys A+ panels for all products. Less variation. Easier to calibrate.