yashsingh1/xdaforums huggingface dataset:
[Nexus 5 Themes and Apps] yorici:
So I have created a gamma reference image for values 12 and 13.

The normal gamma reference image from the DPapp works like this:

The background is made up of 2 colors, black and red (255,0,0). These two create a halftone effect.

The boxes are each made up of one RGB value (Red box 2,2 gamma is 255*0,5^(1/2,2) = 186)

If the box and the background match, the gamma is 2,2. The guy that thought of this should be awarded!

I wanted to adjust this, so I edited 255. (I thought that 0,5 shouldn't be edited as this represents equal shadows/highlights (atleast, that is what I think)

I modified 255 to 127. The background was a mix of black and red (127,0,0). The boxes follow the formula 127*0,5^(1/x) where x is gamma. So for the box gamma 1,5, the colour of the box should be 127*0,5^(1/1,5) = 80. And for gamma 2,2 93

93 is controlled by the 12th and 13th value(based on previous banding tests), so gamma 2,2 in this image is controlled by 12th and 13th value.

The image only works in Landscape mode + using Quickpic. The normal gallery app messes with the image I suppose. (maybe other image viewers work too, I only tested QuickPic)

Photoshop step by step (some basic PS knowledge recommended:)

1) Load .psd file (Download)

Background layer selected:

2) Zoom in to pixel level

3) Make a 2x2 square you preferred pattern

4) Select the 2x2 square

5) Edit - Define Pattern

6) Edit - Fill (select your pattern at custom pattern)

Background should now be using your pattern (Check RGB values: Window - Info *checked*)

Layer 'Rectangle' selected

7) Use the formula 255*0,5^(1/x) (x=gamma, 255 with your custom value)

So for first gamma, gamma 1,5: 255*0,5^(1/1,5)=161

8) Change color to (161,0,0)

9) Use paintbucket to fill box 1,5 with Red-161.

Repeat 7-9 for box 1,6 to 2,7

10) File - Save for Web - Preset - GIF 32 No Dither

selective,no dither, no transpararency dither (but transparency checked), colors 32, convert to sRGB unchecked

11) Load up to your phone and view with QuickPic

The image is not yet as perfect as in the DPapp. This is due to red-127 instead of red-255. If you would create an gamma reference image with red-255, you would get a perfect image. That is why I don't if this exactly works! If someone with a colorimeter could test it, it would help the community greatly!

Edit: XDA messes with the RGB values: Download zip
[Nexus 5 Themes and Apps] nexusmaniac:
Hi rajendra :) have you made any new colour profiles? I really loved the sanity v2 and just wondered if you had made a v3 possibly? Thanks :)
[Nexus 5 Themes and Apps] rajendra82:
I haven't made any new versions since then. I will post here if I do.
[Nexus 5 Themes and Apps] yorici:
What do you think of my previous two/three posts?
[Nexus 5 Themes and Apps] rajendra82:
I haven't had a chance to read through them yet. I will try to do that when I get through with my current project at work.
[Nexus 5 Themes and Apps] yorici:
Ok, I had some time so I made some gamma reference images. These are easy for registervalue 11-14. But for registervalue 10 and lower you will need RGB values above 255 (which don't exist) and higher than 14 the differences in RGB values are sometimes 0. (If the differences are 0 there won't be difference in the boxes. So for example gamma 2.1 would be the same as gamma 2.2)

For the registervalue 8,9,10 the problem was that the background would need to be (255+,0). So I though why not (for example for (305,0)) do then (255,50). This still creates the same half shade. But this got me weird gamma's. So I tested the same for value 11. The background has to be (240,0) and I used (220,20). The gamma reference images were not the same!

Explaination for that:

It's quite simple exactly: The gamma for Red-240 is not the same as the gamma for Red-220. Same for Red-0 and Red-20. That is why the backgrounds of the two images differ.

This also explains why the first registervalue has also effect on the gamma in the DPapp. The DPapp uses (255,0) for background. The first value is responsible for Red-255. The 24th value (responsible for Red-0), not present in the Faux app, would also influence the gamma image in the DPapp.

The question that rises now is: Which gamma reference image is more reliable? Using background 240-0 or 220-20?

This uncertainty applies to every gamma image... I hope we can assume that if you have the 1th and 24th registervalue at 0 you get Red-0 and Red-255 correctly.

Edit: It might be possible to have all gamma images using background Red-0 and Red-255 and calculate the RGB values for the gamma values. As far as I'm concerned not. In the formula 255* 0,5^(1/2,2), the 0,5 is a reference for the halfshade. The gamma has to be 2,2/2,3. And if we would really want to use 255, we can't change 255 either. Thus every value has to remain the same if you would want to use 0;255 for the background for every registervalue, and this is not possible.
[Nexus 5 Themes and Apps] yorici:
After playing around with this app and some gradient images, I came to the conclusion that there is even logic in the banding.

Banding is caused if the difference between colour(X) and colour(X+1) is too big. If you change one of the registervalues to 255, you will create banding. This is useful to measure as it is an indicator for the range of colours the registervalue affects.

The logic is the following:

Change a registervalue to 255 and you will see a banding appear. There will be a colour (RGB-value) that will outstand the most. That colour that ismost affected by that particular registervalue.

The banding is symmetrical: Values 13 can be found doing this: 255-value12. This applies to value 13 to 24. (Value 13 will also be 255-value12 ofcourse)

Change the first 12 registervalues individually to 255 and measure the colour that is most affected.

Result: 255, 254, 253, 251, 249, 247, 243, 235, 223, 203, 175, 143

The minimal color that will be affected by registervalue(X) is: 'most affected colour registervalue(X+1)' + 1

Example: Take registervalue 11: The minimal color that will be affected is: 143 + 1 = 144

The maximum color that will be affected by registervalue(X) is: 'most affected colour registervalue(X-1)' - 1

Example: Take registervalue 11: The maximum color that will be affected is: 203 - 1 = 202

If you mirror the registervalues 1-12 to get the values for 13-24, you must switch the maximum values with the minimum values for values 13-24.

The result is included in the spreadsheet, pdf and this image:D.

As the colours are not always influenced 100% by the register, we must find a way to measure the influence of the register on a colour percentually.

(Colours in this post should be read as a single RGB value, not as in colour like red, green, blue, yellow, etc)
[Nexus 5 Themes and Apps] ISDP:
Here's my profile, as close as i could get to 2.2
[Nexus 5 Themes and Apps] yorici:
And how did you confirm the gamma was 2.2? I hope you read the previous five posts stating that using the Display Tester app to test gamma is insufficient. Or did you use a colorimeter? Because that would be the proper way;)
[Nexus 5 Themes and Apps] ISDP:
Oh damn. :(

Oh well... at least i tried >< i'm new to this stuff.
[Nexus 5 Themes and Apps] yorici:
Doesn't matter;) But you must know that every display is different. So even if your profile was truly gamma 2,2, there would be a likely chance it wouldn't be truly 2,2 for me.
[Nexus 5 Themes and Apps] Assaultersol:
Does my nexus 5 need to be rooted in order to use this apps?

Thanks for answering..
[Nexus 5 Themes and Apps] yorici:
You need a custom kernel and therefore you also need root:) If you have any doubts whether to root, I would root your device. Your experience just increases with this awesome phone. Especially in this nexus community!
[Nexus 5 Themes and Apps] yorici:
[MENTION=4152171]myfluxi[/MENTION] [MENTION=3332811]faux123[/MENTION] [MENTION=3292224]franciscofranco[/MENTION]

Hi guys,

I have a couple of questions regarding the way you guys interpreted the code in msm8974-hammerhead-panel.dtsi:

Why did you call 'D8 20 20' the white point? Is this a guess? Or do you really know this controls the white point?

(I have some problems explaining the behavior: If you set the WP at 63, vertical lines appear and the display is generally bright. So my guess is that the crystals do bend the light (because the display is brighter in general). But if you set the WP at 0, horizontal lines appear. So the crystals don't bend the light 90 degrees. Yet, the light goes through the filters. And strikes me pretty weird. Maybe the crystals bend the light 1 degree? So then "D8 20 20" acts as voltage multiplier, but I don't see that as the white point. (Or am I just wrong here?) So please explain it to me:))

Don't these lines matter? (These appear the first in Adjust the gamma setting for ORISE LCD)

C5 92 D6 A0 15 A0 1E A0 06 (line 1168)

A0 0C 44 33 30 88 (line 1169)

What do these lines mean? (They have been present before the commits by Devin Kim

2A 00 00 04 37 (line 1173)

2B 00 00 07 7F (line 1175)

(Line numbers from this version: Update the gamma setting for ORISE LCD)
[Nexus 5 Themes and Apps] myfluxi:
You already linked the exact commit that holds the reference to the "white point".

There is no documentation from LGE/CAF/Orise available to us so you might want to send an email to Mr Kim like I did (actually twice). Good luck.

Here is a commit with some comments: https://www.codeaurora.org/cgit/qui...1&id=24d07ac32654b298e5ea3985d9880872c627f76f
[Nexus 5 Themes and Apps] yorici:
Ah stupid of me. He said it in the caption above. And thx for the link, it helps with my understanding of it.
[Nexus 5 Themes and Apps] yorici:
I still don't get how it is possible. If you don't know a LCD is made up: https://www.youtube.com/watch?v=jiejNAUwcQ8&feature=youtube_gdata_player

Then change the white point to 63 and view the image I included.

How is it possible to get a white hue from the top to the bottom if the backlight gets evenly distributed? It is if like the screen leaks light... It would be logical to affect all blacks or all the white, but not partially. Have an explanation?
[Nexus 5 Themes and Apps] myfluxi:
Nope.

Regarding one command sequence you mentioned: https://github.com/myfluxi/kernel_msm/commit/56f340db8bb65afd37ed4feef051fe693a2af676
[Nexus 5 Themes and Apps] yorici:
The 'white point' indeed controls the white point. But it is easy to understand in a curves graph instead of this kind of white point:

I created this image:

Our range is 0;255. But it is divided by 64 making the first usable range 0;63. This doesn't matter as lower/higher white point doesn't make your display look better;). According to this the stock white point should be 31 (then the white point is at (255,255). But they might have thought calibration at WP 32 was better than 31.

The white point should function then as gain:

I still have to find a way to prove this. This is hard as my display isn't perfect gamma 2,2. So the RGB values aren't perfect and thus can't I just take a image filled with RGB-200 and then measure the multiplication using a gamma reference image. Though it would explain why on WP 63 and 0 the diversion between RGB-223 and 224 is so big..

I think the multiplication factor would be (224 + White Point)/255

Should the white point be 31? Measurements:

The colour temperature will probably be lower with WP=31 instead of 32, but gamma will be higher. A lower colour temperature will create a warmer screen, but gamma is higher. If at WP=31 the whitepoint will be at 255,255 the contrast ratio will be the highest compared to other white points. So lower colour temperature, higher gamma and higher contrast ratio at WP=31. But the differences are not that big.

LG (Devon Kim) might have though colour temperature was more important and thus set the white point at 32.

[MENTION=3250376]ChazzMatt[/MENTION] I owe you an apology;) Setting the white point at 31 is actually more 'stock'. I will continue my measurements with white point 31.

[MENTION=4437173]Piereligio[/MENTION] It's up to you what you find more important: colour temperature or gamma&contrast ratio.
[MENTION=2752629]rajendra82[/MENTION] [MENTION=4909585]gpvecchi[/MENTION] [MENTION=5543250]mag01[/MENTION] Agreeing to this explanation?

So feel free to set your white point at 31. It's all a matter of priorities
[Nexus 5 Themes and Apps] ChazzMatt:
I knew it looked good at 31. I've worked in TV professionally for longer than I care to admit. :) I work with dozens of expertly calibrated monitors every day. I know my eyes are not the same as using a wave form monitor and vector scope, which I use at work all the time... But by now I can tell what looks good and bad. :)

_______

Sent from my Nexus 5 (LG-D820)
[Nexus 5 Themes and Apps] tesp88:
If I understood it right, you wrote that the Display Tester app shows incorrect gamma in all cases when WP doesn't stands at 32? If this logic is correct, does it mean that only way to set up gamma using Display Tester app is still with WP 32?

Or this new information means that I can set up it with WP 31 without keeping in mind any significant corrections to the results shown in DTa?

Thanks!
[Nexus 5 Themes and Apps] yorici:
The Display Tester App is flawed any how. Check posts page 101. It only measures one RGB value.

If you were to measure your gamma, setting the white point doesn't make it faulty. It just changes the gamma. Though, it must be noted that measuring gamma requires three RGB values. A low one (i.e. 0), high one (255) and the value you want to test. Changing the white point won't have affect on 0, but will have effect on 255. Lowering the white point means that you will never reach 255, therefore making the measurement kinda faulty. But when you talk about whitepoint changes of 1 or 2, the effect is little and thus is the measurement not necessarily faulty.

It might be a bit hard to follow, but it helps to read the last 15 posts.
[Nexus 5 Themes and Apps] zubsz:
I hope this isn't a stupid question, but will this app work on stock room rooted?
[Nexus 5 Themes and Apps] :
Hi,

Not at all, the kernel needs the interface for colour control "hardcoded", so it's not possible with the stock kernel. It's on the kernel side, not the rom.

You need a custom kernel like Faux123, Franco kernel, ElementalX...

:)
[Nexus 5 Themes and Apps] El Nino1977:
Stock rom with fauxs latest kernel will be the perfect combination. That's what I'm on, works perfectly...
[Nexus 5 Themes and Apps] caalca:
Hi, I have been trying to understand this thread but I can't. I just want reach a 2.3 gamma like an amoled screen. I know that the colors are very saturated but I love saturated colors.

Can anybody help me giving me the values?

How do I meassure the gamma? How do I know that I am getting closer to a gamma value?
[Nexus 5 Themes and Apps] yorici:
There no 'the values'. You can try some profiles ( http://xdaforums.com/showthread.php?p=49561443)

The measurement of gamma is still a problem, I'm working on it. Check page 101 why the Display Tester App is unfit for checking gamma.
[Nexus 5 Themes and Apps] AlexC1984:
could someone kindly write the values ​​of the setting "vivid" of chaos kernel?

Thanks
[Nexus 5 Themes and Apps] Smoothface:
You would have better luck going to the thread for that kernel and asking there for the values he used. Otherwise asking how or where you can get it would be better than asking someone else to do the work for you.
[Nexus 5 Themes and Apps] Wezi:
If you're on Franco Kernel i strongly recommend the 'Hellooo_Saturated_Colours' profile if you want deep colours like Amoled. I don't use it myself (preferring yorici_v3) but i was surprised to see that it didn't sacrifice brightness and contrast although you can forgot about 2.2 etc.

p.s. I always use the 'Red Wedding' clip from Game of Thrones on YouTube to test the blacks

---------- Post added at 11:20 AM ---------- Previous post was at 11:14 AM ----------

Forgive my Ignorance but....

I'm using Franco Kernel which gives the options to modify Gamma in the same areas as the adjustments recommended in post 2 by Faux123 (thanks :good:). Now i know its not all the areas you can tweak using Fauxs' app, but is it essentially the same difference. I've used Fauxs' app to make the adjustments, and i've made the same adjustments using Francos' app. Seems the same to me.
[Nexus 5 Themes and Apps] JaylanPHNX:
Could you link to the post with this profile? I searched and searched and couldn't find it.

Sent from my Slim Nexus 5 with smoothness by Faux.
[Nexus 5 Themes and Apps] :
Hi,

Here's: http://192.227.135.147/N5_ColorProfiles/Latest_Profiles/.

Thanks to vomer ;)

:)
[Nexus 5 Themes and Apps] yorici:
Actually the fku app only adjust values 1, 10 and 11 + white point. Those are the values that influence the 4RGB values that make up the gamma image in the Display Tester app. It is in no way the same;)

Edit: I might have misunderstood you. Let me put it this way: The adjustments using the FKU app can also be made using the Faux App, but the adjustments made using the Faux App cannot be fully done using the FKU app. Most profiles (I hope, but most good profiles) adjust not just 3 out of 24 values, but 23 values out of 24. (24th is not available). Either way, adjusting just three values dramatically is wrong and will result in banding.
[Nexus 5 Themes and Apps] Wezi:
Excellent, thanks for the info. Btw when you're referring to profiles we're talking about profiles created for the faux app right? Does this mean that yorici_v3 on fku app is only updating 3 values?
[Nexus 5 Themes and Apps] willybarca:
yes could u let us know which profiles use 23 values
[Nexus 5 Themes and Apps] yorici:
No the profiles came when the FKU app created the possibility. Some people might have only adjusted 3 values, but when doing that, you don't achieve a lot of result. Therefore I assume that the popular profiles, (Vomer, Perigilio, The Gingerbread Man, Rajendra82's, etc etc) have adjusted more than 3 values. I modified my display to my likings using the faux app, but I then saved the setup using the FKU app. They both access the same data, it just that Franco only put in 3 values. Otherwise you would need to have 24 sliders per colour... (It's still a beta). So when you load yorici_v3, you will update all the registervalues, no matter if they changed or not. (In this case I changed 21/23 I believe).

---------- Post added at 09:48 PM ---------- Previous post was at 09:45 PM ----------

See post before.

Also you can check:)

Install the Faux App (This thread)

Check the values after you rebooted. Those are the stock values. Screenshot it, write them down or remember them.

Load up a desired profile using the FKU app.

Relaunch the Faux App.

Check if the first 9 values are the same as stock.

If they are, it's likely the maker only adjust three values. You can check all values ofcourse, but 9 will probably do.
[Nexus 5 Themes and Apps] occtec:
[MENTION=3332811]faux123[/MENTION] do you have a similar app for the Nexus 7 2013?? Just tinkering with my sons tablet and would love to improve the display. Cheers
[Nexus 5 Themes and Apps] El Nino1977:
Fauxs kernel app will change gamma values for the N7
[Nexus 5 Themes and Apps] occtec:
Thanks for your reply! I noticed there are no profiles within the app, any recommended values or anywhere I could get recommended values for the Nexus 7 2013??

Thanks again.
[Nexus 5 Themes and Apps] The Gingerbread Man:
Ooh this works on the n7 too! Now my n5 screen is to my liking im finding the defaults on n7 a little warm. Will try when I'm home.
[Nexus 5 Themes and Apps] defffizz:
I like stock calibration on n5, but I was curious if the screen can look better after tweaking, so I flashed franco kernel and installed his display control app, and after using mag01 settings (like them a lot), I found perfect profile for my screen: settings from yorici3. Not only do they give me almost ideal gamma 2.2, but they add more contrast and saturation to pictures while keeping bright, balanced and natural look to them. Very happy now, my screen is perfect! Thanks yorici!

Bright Red Nexus 5, PA + franco
[Nexus 5 Themes and Apps] The Gingerbread Man:
Just to clarify do you need faux kernel to make this work on nexus 7? I'm on franco and getting a warning of an old incompatible kernel driver.
[Nexus 5 Themes and Apps] yorici:
CHECKING COLOUR TEMPERATURE (More useful for profile builders/editors, but anyone can check it)

Had these lying around and I'm releasing them now.

These are 19 shades of grey.

You just swipe through them with any image viewer. If you find an image being too reddish, check the title of the image and adjust the appropriate value.

In depth explanation:

Reading this will show you that CT is dependent on the mixture of Red, Green, Blue.

Therefore I took shades of perfect gray (thus R=G=B; 175;175;175)

It is inefficient to take all gray tones (0 to 255: 256), but it's easier to take the ones that are most affected by the values.

Therefore I turned to a previous post of me.

I didn't bother to take the lowest values, as the difference isn't visible anymore (atleast to me).

When too reddish: decrease red, or increase green and blue (etc for the rest)

Have fun.

Formulas: The pdf linked contains multiple formulas. You can apply them onto the register, but I'm not sure if this is actually valid. Our register is a LUT, not actual results. It is interesting however that stock settings come around 6400K. If you really want to see the formulas in action and you are unable to import them yourself in excel, PM me. Though it should not be taken as reference for CT (yet).

(Repost from Franco thread for those who follow this thread instead)
[Nexus 5 Themes and Apps] yorici:
Can you check out this app?

https://plus.google.com/communities/103123288128442067861

I contacted owner but he doesn't respond. To my understanding you need a colorimeter for this app. If not, he can provide a lot of useful information for the N5. I don't have a N7, so can you check it?
[Nexus 5 Themes and Apps] El Nino1977:
Cheers GB, I had no idea on francos N7 compatibility as don't use his kernels. I'm always switching between faux or flars as they both have the gamma values activated.
[Nexus 5 Themes and Apps] show-p1984:
Wrong.

White point maxes out at 111111 base 2 (63 in base 10) and is repeating after that for obvious binary reasons.

(Because 64 base 10 would be 1000000 base 2 and since everything past 6 bits is cut off we would be back to 0 base 10. Same goes for 128 base 10 which is 10000000 base 2, etc...)
[Nexus 5 Themes and Apps] yorici:
Hi, you are in fact right and we know this for some while, but faux hasn't been studying this for a long time. He is using old information from november 2013. Since then we know so much more.

Since you do know a lot more than the average joe, do you happen to know the following:

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

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.

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:

.

Now the problem is, I don't know if this is correct. You could also view the white point as gain and create this formula:

.

You take 223 as base for Whitepoint=0. If the whitepoint is 31, then the formula uses 255.

Do you know what the appropriate formula should be?
[Nexus 5 Themes and Apps] show-p1984:
Hi I think you meant that 31 is the middle. 0-63 = 64 numbers. 0-31 = 32. (we are counting the 0 in computer science)

Sadly The images you posted with the formulas won't load for some reason. So I can only guess. But my guess is that with any luck (and correct math on your end :)) your issue might be solved when you use 31 instead of 32.