yashsingh1/xdaforums huggingface dataset:
[Nexus 5 Themes and Apps] Zorrich:
Doesn't appear to me that they look warmer as I drop WP, but I haven't spent much time on those settings. Tried it now to see if I could see a tint and at first glance they look really nice, if your interested in saturated colors.

I will say that I am on multiple Nexus's. The first had a perfect screen, and if I could go back I would have kept it. The colors out of the box were great, but the vibrator sounded like kermit the frog (in hindsight I would have turned vibrate off and moved on). Sent that back and got another with an extremely yellow screen. I used your settings and they were spot on, so I was happy. That phone just stopped working on me (couldn't turn it on at all, just died) so I got another. This one seems to be in the middle of the 1st and the 2nd as far as yellow tint goes. When I used your settings on the 3rd they came out too blue. That is when I tried GUGUITOMTG4 settings and they are perfect for this phone.

Hope that answers your question.
[Nexus 5 Themes and Apps] italia0101:
I like your settings, cheers dude
[Nexus 5 Themes and Apps] Zorrich:
I like his settings too, I have them printed off on my desk :) Just found that on my new phone they are slightly blue for me. That being said, after reading his explanation about WP (lower warms the screen), I bet I would just have to lower the WP

down

(I had been going higher). Will try later on when I get home.
[Nexus 5 Themes and Apps] yorici:
I saw your post before, but now I had time to test some things. The best setting with this app imo is the following:

Example: Lets turn red off: Set values 1-12 on 255, and value 13-23 on 0 for both positive and negative. The same principle applies to blue and green.

Though, note that if you were to disable green and red, red seems to appear in some shades again. That's something I can't figure out. :/

What kind of formulas did you have in mind? Formulas regarding gamma as variable? (So you put in your desired gamma? Because that's too difficult because of all the different displays)

Or did you have an app like 'Nexus 4 Display Control' in mind? Because from the looks of it, this seems to be based on color intensity. Maybe the same algorithm could be used for this app? (Or change the algorithm a bit so it matches our 23 points)

Btw is it possible to revert the distinction between positive and negative? I know faux was against it, but perhaps he has changed his mind by now. It's more of a ease of use thingy (it saves me and others from typing 138 values :D).
[Nexus 5 Themes and Apps] fireproofrev:
I think this is the only important thing! Every time you want to change something within a color (higher or lower the color to blacks or whites) you have to change value 1-12 simultaneous according to the stock values without changing the stock curve. The same also for 13-23.

This sliders you need for each color (RGB) for 1-12 and 13-23. I dont know if it makes sense to change positive and negative individual.

I experienced that changing the stock curve will lead unavoidable to bending.

Unfortunately I have just basic script and coding knowledge, I would give it a try and develop an app according to this scheme.

Can make an more detailed scheme if you don't understand what I mean
[Nexus 5 Themes and Apps] yorici:
Banding:

Bending =banding right? To determine which value causes banding, you should change all 23 of them independently to 255. This will create a band obviously. Now you measure from the side of the screen the distance from edge to band. So if you run in to banding, you can measure that distance and track down which value is causing it.

Negative/Positive:

In my opinion this does not add anything positive (see what I did there :D) They should remain the same at all times or distortions will appear.

Scheme:

What do you mean with a scheme? You mean code for the app to handle the input from sliders to the 23 values?

What about this idea: You create a plotted graph with the 23 values for each color. Then you are able to control each color with dragging the points (and thus the line) up and down.

Furthermore, when you get into coding/formulas: http://xdaforums.com/showthread.php?p=48279955#post48279955

I found this to be very useful!

But I'm very curious which algorithm lies beneath the Nexus 4 Display App. I mean, how do they combine the 23 values. When doing the measuring with banding, you will notice that some values take up more banding than other. Would it be an idea to add some sorta weight to the values according to this?
[Nexus 5 Themes and Apps] GUGUITOMTG4:
From 1-5 work different than from 6-12.

You increase the color when increasing 1-5 values.

You decrease color when increasing 6-12 values

so, there are 3 sections not 2.

1-5, 6-12, 13-23

Neg & Pos when are not matching, the Display Tester app wont show accurate scales. (will be harder to read)

So, is better when Neg & Pos match to read on the DT app
[Nexus 5 Themes and Apps] GUGUITOMTG4:
I hit it lol

Happy 30000 thanks faux123:good:
[Nexus 5 Themes and Apps] yorici:
In my opinion every value specifies a certain range of shades, but some values, like value 1, have a langer range. You can test this when you change each one of them in to 255 one at a time. You will see the 23 different bands. The thing is that some bands are closer together than others.
[Nexus 5 Themes and Apps] myfluxi:
Search through my postings in this thread. I linked the commit history of the gamma table, the changes should give you a good impression of what to expect.

I consider the distinction between positive and negative polarities useless as well.
[Nexus 5 Themes and Apps] Web_E:
I was following this thread quite few days & I failed to understand anything. So I went to test the modified franko kernel by phantom for the color tweak. I was pretty happy with it.

So that was the last thing I did with my last nexus 5. I didn't use any other function like DT2W/S2W. It didn't last for 24 hour.

I set alarm for morning & in morning the device was hard bricked. The device was bought 21 days ago. Running franko kernel ever since and stock rom.

I am not saying that due to the color hack in kernel, my nexus 5 got damaged. It could be anything, like a sudden hardware failure or some manufacturing defect

But as I got the replacement, I am staying away with any such hack & I am scared to use this app as well.
[Nexus 5 Themes and Apps] Batfink33:
Franco and Faux have said that the hack that Phantom uses does not change the gamma values but breaks the timer settings for the screen and it should not be used. The values that are changed using Fauxs app in this thread change the actual gammas values of the phone and do not affect the timer settings of the screen so there is no risk in changing them.
[Nexus 5 Themes and Apps] GUGUITOMTG4:
That's right. However, my idea is to let people know what direction move the settings in order to achieve the desired result.

for example.

I if you increase 1-5 values by 10 each, the gamma will change from 2.2 to 2.4.

but if you increase the values 6-12 by 10. The gamma will move from 2.2 to 2.0. So, they work in opposite direction
[Nexus 5 Themes and Apps] magnamentis:
interesting but ?

hi,

yes, many things are possible but the probability that you go to bed, screen most probably of during the time and when you wake up your phone is damanged during sleep and during screen off does not make it really probable that a screen hack was responsible.

further, albeit it is interesting to gather information about any damage of devices using the hack to see whether there is a pattern to be found,

i believe that if that would be the way the hack could destroy a nexus 5 we would have heard about it before, at least a few times.

i say this because the hack is several months around already and there have been no issues till now and you issue is not only not proven to

be related, it's highly unprobable due to the fact that your phone broke during screen of, at least that is how your desciption has been understood.

however, i as well will happily change back to "serious" tweak as soon as there is one available which gives me the preferred look and

i said prefered not best or anything like that, just everyone has his personal prefs. just a little example before ending this, i really like my

amoleds and the screen tech was one of the greatast consideration whether to buy a nexus or not ( nexus 4 at that time ) and yes it was confirmed, from day one i fight the battle for closes to amoled blacks and saturation which again is prone to personal prefs. but then i have to say clearly, that when i have all my devices side by side with the same screen content on-screen, the nexus looks by far the best and the amoled looks like sh...

compared to that nexus display. only thing i will not alter my opionion are the blacks which there cannot be done much about it due to tech basics.

regards

Current Devices:

N7000, 4.1.2 Stock/TW

N7100, Pacman Rom, 4.3.1, Pac Kernel,

I9100, OmniRom, 4.4.2, Omni Kernel, Xposed Framework

Nexus 4, Cataclysm Rom, 4.4.2, Franco Kernel r201, Dalvik Patched, Xposed Framework

Nexus 5, Cataclysm ROM 4.4.2, ElementalX Kernel w. Cooler Colors, Dalvik & Bionic Patched, Xposed Framework
[Nexus 5 Themes and Apps] yorici:
Okay, these are my findings:

I went up to an earlier version of the code. https://github.com/myfluxi/kernel_m...27#diff-c315586597cff851048c399a4a6f3e66R1155

I decoded all the hexadecimal to decimal and I was amazed by the difference.

Blue stock: 86 87 89 91 94 96 101 109 111 121 126 131 120 116 110 99 84 71 61 52 43 33 20

Blue old: 41 43 46 51 55 60 67 80 87 101 111 119 131 126 120 109 95 84 76 70 62 44 28

Even more amazed was I when I put these in and noticed no banding at all despite the difference.

Conclusion: Banding is caused by altering the curve incorrectly.

So now you may ask, how can one alter the curve correctly? The answer: proportionally

So I tried to multiply the stock values by factor K, but terrible banding occurred.

I changed the order according to mag01's post, and multiplied that with factor K. Result: No banding!

What can one achieve with this:

If one would multiply the changed order (CO) with: (K being the same for each color)

K < 1 ==> Gamma increases

K = 1 ==> Stock colors (duh:P)

K > 1 ==> Negative values occur

One could remove the yellowish tint in the screen by reducing red and green.

What can be altered?:

- Factor K for each color

- Whitepoint

- The curve for each color

[MENTION=3332811]faux123[/MENTION] [MENTION=4152171]myfluxi[/MENTION][MENTION=3292224]Franco[/MENTION]

So the app would contain:

- Three sliders ranging from 0.00 to 1.00 (K > 1 returns negative values).

- One slider for the whitepoint

- An option to alter the stockcurve (either what we have now, or a plotted curve that can be moved for each point)

My spreadsheet for testing:

I included a spreadsheet. In the spreadsheet the only things to worry about are the factor and the stockcurve.

If download fails: http://goo.gl/SpZAtD

Download spreadsheet first.

Disadvantages:

- Although banding will not occur (provided with the right curve), the dynamic range will suffer when factor K gets lower and lower. It's not that noticable on 0.9, but it is on 0,6. (note my gamma is 2.4 on 0.92, so 0.6 is a bit too much)

- Same applies to black saturation, but the effects are not that noticeable on small changes
[Nexus 5 Themes and Apps] DubelBoom:
I have nothing helpful to say, so sorry about that, but I have to say this post is very interesting and educating.

Good job everyone that contributes, shares configs and more, you guys are what makes this community special! :D
[Nexus 5 Themes and Apps] ChazzMatt:
We already have 2.0 out of the box without banding. What gets us 2.2 - 2.4 without banding?

Anything less than 2.22 is not correct. True gamma is a range of 2.22 - 2.4.

Some experts even say a range of 2.22 - 2.5

. But NOT less than 2.22.
[Nexus 5 Themes and Apps] yorici:
I can literally get anything between what I had and above. I already got 3.0 for each color, so 2.4 will work too. Just test it for yourself! Your screen is not my screen, so our results will vary. But if stock didn't cause banding on your screen, it probably won't on another factor K.
[Nexus 5 Themes and Apps] rajendra82:
I took a look at your spreadsheet, and in my opinion that approach is too simplistic. What one really needs to do to calibrate to sRGB standard is to test the screen with a colorimeter, with one color being displayed at a time at varying levels of intensity. This can be achieved with the display tester app gradient pattern generator or a simple full screen paint program, and painting the screen with a custom color (full Red will be have the code FF0000, 50% Red will have the code 7F0000, 25% Red will have the code 3F0000, etc.) The colorimeter will tell you if the displayed color is too intense or not intense enough. Each of the 23 values for red affect different points on the curve (on a logarithmic point on the intensity curve per mag01, so value 1 affects full red, value ). Value 1 affects full red, while value 23 affects 0% red, but to quote mag01, the scale isn't linear. There are 5-6 values at each end covering near black or near full intensity values, while there are a few in the middle that cover a range of intensities. Decreasing values 1-12 makes the lighter reds more intense (because those values are subtracted from 255), while increasing values 13-23 makes the darker reds more intense, because those values are added to zero. Each value should be adjusted based on how it affects its part of red curve, and it should be made close to sRGB standard intensity. Same thing needs to be done for the green curve and the blue curve. Since sRGB standard intensity is a gamma of 2.22 using this approach will result in a gamma close to that. It should also correct color temperature to 6400 K and fix what people say when they have pinkish or yellowish tinted whites. It will also result in no banding when displaying a standard test pattern, because everything has been adjusted to the right intensity. The only person that has used this approach in this thread in mag01.
[Nexus 5 Themes and Apps] yorici:
Mag01 is one of the few people that has a calorimeter... I'm offering a solution for the app and thus the people without a calorimeter. The solution offers a new range of possibilities without having to worry about banding. So now one could focus on changing the portion of one color. So you could decrease the overall amount of red and green and doing so one could probably fix yellowish tints.

The curve that it is based on is not perfect, but that's something that is different for every display. Each display has its characteristics and as long as you don't have banding on your stock settings, you can tweak all the colours to different gammas.

Of course would it be better for everyone to calibrate their own screen with a calorimeter, but few have them. This solution is good for the app. Your solution works for calorimeters, but not for the app. Or am I seeing that wrong? The results based on calorimeters will be sets of values like mag01's valueset. But that valueset is perfect for his screen, but not for screens with other characteristics. There is no perfect onesizefitsall valueset..

My proposal: pick the best curve for your screen you can find without banding and tweak it further with my solution.
[Nexus 5 Themes and Apps] rajendra82:
My point was that the adjustment you proposed wouldn't work on any screen, because it is not based on any testing. I have a colorimeter too, but I haven't had the time to run tests on my Nexus 5. If I did, I would probably find the settings to be very close to mag01, because they appear to do the trick in display tester. If I do the tests and come up with different values, I will post them here. Secondly, I think the differences between different batches of panels are exaggerated by different users having different expectation, so the same panel may be described as neutral white by a person used to a 6400K calibrated IPS display, while called too yellow by a person used to cooler SAMOLED panels. I think it is best to do your own tests, but in the absence of those use someone else's tested values.
[Nexus 5 Themes and Apps] yorici:
Well I think there are differences between the displays, but that a side: my solution is based on the curve the user provides. If that curve is stock, it's tested. Any curve using my solution is just a version of that curve, that is why no banding appears. So the curve is tested, unless they provide an untested curve.

But tested or not, shouldn't the point be if it works or not? Because it works for me without side effects like distortions.. I would really like to know if people are able to remove the yellow tint by reducing red and green.
[Nexus 5 Themes and Apps] yorici:
People should not see my solution as a definite answer. However, it provides options to remove tints and boost gamma at the expense of black saturation and dynamic range of colours. Though, these expenses are not big as the adjustments required are small. Therefore this is a good solution. But the curve is not perfect indeed and we require another dataset like mag01's, just to see if there are many differences in the screens.

Similar apps like Nexus 4 Display Control offer the option to reduce the amount of red, green and blue. My solution does too.

I recommend an app with that solution, a slider for the whitepoint, and a possibility to adjust the curve like we have now.
[Nexus 5 Themes and Apps] yorici:
Repost from franco thread

Okay, I got it. The second (gain) and third (offset) are easy: they follow the formula y=a*x+b

The third is more difficult: If you would do x^c, you would get results > 255

What I did is adding a factor that is value dependent (so value 1 has another factor then value 20). So I added "weight"

How: (#/23)^c (So value 20 would be: (20/23)^c

This gets you a number between 0 and 1. We multiply this with the stock values.

Following the order of operation we should first do the exponents, then multiply, then substract/add:

Formula: a * stockvalues* (#/23)^c + b (where # is a value between 1 and 23)

I don't like the formula that much as the exponent is too aggressive, but I think this is a start.

In the spreadsheet there are for each color three blue boxes. They each represent a slider and alter the curve.

On the bottom is the cell with the complete inputvalues to import for franco's app. Don't use notepad. Use word or wordpad for copying these values.

Repost from franco's kernel thread.
[Nexus 5 Themes and Apps] myfluxi:
Maybe this helps you for your calculations. The formulas for gamma correction are:

corrected = 255 * (original / 255) ^ (1 / gamma)

or

original = 255 * ((corrected / 255) ^ gamma)

There you have your weight.
[Nexus 5 Themes and Apps] The Gingerbread Man:
What screen brightness % would you knowledgeable guys recommend when trying to match gamma to 2.2 with display tester application?
[Nexus 5 Themes and Apps] yorici:
Yeah i tried that earlier, but it doesn't work that well. The same problem occurs: the curve can curve below the stockcurve, but not above. When you try that, the first value doesn't stay close to stock, it's all over the place.:( The last value however does.

---------- Post added at 11:38 AM ---------- Previous post was at 11:37 AM ----------

I recommend using the same brightness at all times for testing. I have it at 100%, but I don't have strong arguments for doing so.
[Nexus 5 Themes and Apps] The Gingerbread Man:
Yeah I guessed the reason mentioned it is I made a fku colour profile which with my usual screen % was very close to 2.2 gamma for all colours but when I increased screen brightness it turned out to be closer to 2.3 - 2.4 gamma. Still looks good through. Cheers and I wish you luck with your maths formula!
[Nexus 5 Themes and Apps] GUGUITOMTG4:
I think 50% is more reasonable as it will be more balanced for regular usage.

You won't use 0% all the time and 100% neither. so, go in the middle.
[Nexus 5 Themes and Apps] The Gingerbread Man:
That was something I wondered about, then thought about why peoples gamma readings for different profiles could be different. People will use different brightness % and that seems to effect the display tester application so everyone should all test at the same screen brightness and like you say 50% is a good place for normal usage. Reading around iv only heard of screens that either have yellow tint, or ones that don't. It would be interesting to know exactly how many panel types there are as it would be easier to know which type of screen to calibrate towards using the knowledge that say type 1 needs more green and type 6 less red for instance
[Nexus 5 Themes and Apps] droid@xda:
Display tester app automatically increases brightness to 100% while checking gamma. So where's confusion?
[Nexus 5 Themes and Apps] yorici:
Hi, setting your brightness in Android on 50% doesn't work. That is because the brightnessslider is not linear, it's exponential. If you set it at the same brightness every time, it doesn't matter for the comparisons. I use 100% because it is easy.

---------- Post added at 03:29 PM ---------- Previous post was at 03:28 PM ----------

It doesn't for gamma?
[Nexus 5 Themes and Apps] GUGUITOMTG4:
Also true. but he asked withing the DT app by scrolling up & down. not android display settings slider. What happens is that if you want to keep the rhythm usind DT app, you better use the same amount of brightness (in your case,100%) and an amount similar to what you will se everyday or then, you might not enjoy your end settigs as it will be 100% exact only when your phone is at 100% brightness. Btw I dont know the technical details as you do, but visual judgement is what makes people decide
[Nexus 5 Themes and Apps] yorici:
But it isn't linear either in the DT app. Anyways, i agree with you about the same amount. Use the same percentage every time you compare settings.
[Nexus 5 Themes and Apps] GUGUITOMTG4:
Understood, if you meant that 50% isnt

in de middle exactly. I remember from CM7/9 Advanced auto brightness settings.:p
[Nexus 5 Themes and Apps] faux123:
[ ANNOUNCEMENT ]

Test App Version 11 is out!

***** WARNING *****

PLEASE WRITE DOWN YOUR SETTINGS BEFORE UPDATING TO THIS NEW VERSIONS. UNINSTALLATION IS REQUIRED TO INSTALL THIS NEW VERSION!

***** WARNING *****

-- The reason for this is that I've been using a DEBUG KEY for releasing all the past versions. THE PROBLEM with using debug key is that it's UNIQUELY GENERATED on the MACHINE you were working on. I've updated my machine, so the OLD DEBUG KEY no longer works. From Version 11 and beyond, I've use my OWN PRIVATE KEY. This way will allow me to develop on ANY MACHINE including my laptop rather than tied down to a specific machine.

Version 11 Changelog:

Updated to work with [MENTION=4152171]myfluxi[/MENTION] 's stable sysfs interface.

Enjoy!

Again, sorry for the lack of replies or participation, I've been EXTREMELY BUSY @ work and @ home. My time is extremely limited.

Thank you for your patience!
[Nexus 5 Themes and Apps] faux123:
Well, it's been a while since we last discussed this issue. If you guys feel that the distinction between + and - is no longer necessary. Go ahead and remove it and I will do so as well for the app.

Just PING me with your decision so I am aware of it.
[Nexus 5 Themes and Apps] franciscofranco:
Last time I spoke with myfluxi (last night) it was discussed that the negative arrays would be going away, so I'd say that's about to happen sooner or later.
[Nexus 5 Themes and Apps] rajendra82:
I was on Franco kernel r31 and tried r32 as well, but am getting an old version error message with test version 11. I guess we will need to wait for r33 to implement the new and stable sysfs interface.
[Nexus 5 Themes and Apps] franciscofranco:
Exactly. I posted a working code solution for faux to find dynamically the gamma dir, but I guess he didn't use it...
[Nexus 5 Themes and Apps] Garrykd:
Same here.

if I revert back to the version 10 beta of the app everything is ok.
[Nexus 5 Themes and Apps] hello00:
maybe he missed the post
[Nexus 5 Themes and Apps] GUGUITOMTG4:
working well with faux kernel 008u