yashsingh1/xdaforums huggingface dataset:
[Nexus 5 General] yorici:
Hi there,

@1) I know it should be, but it isn't. I already contacted a similar app developer earlier and he recognized the problem. You should screenshot the gamma image and open in Photoshop.

@2) Typo;)

@3) How do you add 25%? When you can only use 0% and 100%? If you are using the "calibrated" 50% the inaccuracy will rise.

@4) I know, but the masses think so...

@5) Sure do, I have tried for months to develop methods to measure gamma and I already thought about 0%,12.5%,25% etc etc, but it just gets inaccurate.

My point in the post is that people take the value that your app provides as 100% accurate and it isn't. Too many variables and the images aren't 100% correct.
[Nexus 5 General] yorici:
Contacted you on Hangouts btw
[Nexus 5 General] nihil0:
Hi,

@1.) I know that it is hard to generate a picture which is not stretched on the display and is pixel accurate, but Display Tester does exactly this. You can check it exactly as you wrote, with screenshot and Gimp.

@3.) 50% uses a pixel grid which is 50% 0 and 50% 255.

- 25% uses a pixel grid which is 25% 0 and 75% 255

- 75% uses a pixel grid which is 75% 0 and 25% 255

That's the magic. ;)

The masses do not need a 100% calibrated display, just a good one. To decide whether the display is good enough is Display tester the tool. For calibrating the display an other tool must be used.
[Nexus 5 General] yorici:
I'll check again. Maybe you corrected it, but I doubt it. DS Display Expert(Lite) has the same problem

EDIT: Tested again. Still there..

No they don't need a 100% calibrated display. But when they think they know gamma when they are actually trying to calibrate, it is certainly wrong! People are going to use the app for tuning the parameters (history has shown this) and then this becomes a problem.

Good method ^, but does it work for RGB values near to 0 and 255? I have noticed that boxes tend to get the same RGB value. The inaccuracies remain though:(

Edit: Reviewed the method. Pixels don't blend in, so checking becomes much more difficult. And only 25%/50%/75% are available. You will always keep the problem that 98% of the RGB values will not be measured..
[Nexus 5 General] nihil0:
The Display Tester app can be used for testing if the calibration is right and not in the other direction for calibration.

I tested how the Nexus7-2012 deals with the checker board patter (50% with red background). I got a very interesting outcome.

Steps:

1.) I displayed the checker board pattern on the device (2 different ways: 1 - from an app, 2 - with QuickPic a checkerboard png image exactly the same size as the display with 1:1 zoom level)

2.) I made a screenshot

3.) I opened the screenshot in GIMP (like photo shop but free and running in Linux)

4.) I realized, that the original colours are distorted

5.) I looked for black pixels which are not black, and I highlighted them (16 = white, 12 = yellow and so on)

6.) The outcome shows me, that this problem is device related. The device screws the picture somehow. I can't explain it.

Here is the picture:

The same picture zipped: View attachment Screenshot_2014-06-01-15-41-15_PIXELHIGHLIGTED.png.zip
[Nexus 5 General] yorici:
Yes it is an Android issue, but why is this caused? Wouldn't this mean that every image gets distorted a little bit?

Btw, isn't this an extra reason why gamma can't be measured without proper equipment? (assuming that screenshotting doesn't mess with the image).
[Nexus 5 General] ankit7070:
Superb

Great one. I think almost everything is covered.
[Nexus 5 General] Tzfardaya:
just out of curiosity... why would you quote the entire op?
[Nexus 5 General] vksjangra:
Is it just me or the colour profile looks a little tweaked to remove yellow tint in 4.4.3?
[Nexus 5 General] yorici:
Which profile? Stock? It could also be that the glue that was originally not yet solid, is solid now. This used to cause a yellow tint then. This only happens though when you own your Nexus for a short period of time? Do you?
[Nexus 5 General] vksjangra:
Yes the stock profile, and I am using Nexus 5 from mid jan.
[Nexus 5 General] yorici:
I don't think Google messed with them. It's too specific. Could it be that you switched from stock early (in January) when the glue was causing a yellow tint? So you experienced stock quite yellow. Now the glue has dried, you once again see stock and experience stock without the yellow tint?
[Nexus 5 General] vksjangra:
May be and yes I switched from stock to custom in just 2-3 days after receiving my device.
[Nexus 5 General] tmagritte:
I'm interested in calibrating my display and I have a Spyder4 colorimeter. I'd like to avoid switching to a custom kernel, though. Is there any way to enable color calibration on a stock kernel (flashing some patch, xposed module, etc?).

If not, is there any custom kernel that only adds custom color calibration features but is otherwise stock? What kernel supports this that is closest to stock?

Any indications that Google plans to add this feature to future stock kernels? This seems like something that should be built into the OS, even if it's only available through APIs with no default end user facing component.
[Nexus 5 General] Tzfardaya:
No, I don't believe so.

I haven't found it if there is.

And no, they seem to prefer people not messing around at the hardware level on stock
[Nexus 5 General] tmagritte:
So can someone recommend the least customized kernel that would let me play with this? Or at least one that is generally as stable as stock?

As far as messing around at the hardware level, it's the OS that should be doing that but providing an interface to the user or to apps. Windows, OS X, and I presume Linux all have complete color management systems built in. I can't think of any reason why Android couldn't offer the same. I suppose there's a fear the user will mess up the display and make it unusable. But that's why hiding most of the controls from the end user might make sense and then the typical support script requiring a factory reset would fix any user/app induced problems. But I'm sure Google is not reading this so I guess I'm just venting.

Thanks.
[Nexus 5 General] Tzfardaya:
Macos and Windows have full ICC support, Linux does not, but it can be hacked in...

No cell phone that I know of has true ICC support, even what we are doing here isn't using an ICC profile, but rather fiddling with the setting that (I'm assuming) adjust the voltage outputted for each colour level. (which is why you can't just use your desktop calibration app to test your phone and generate an ICC profile for the phone to use (which is basically just a lut, when this colours is requested, display this one instead)
[Nexus 5 General] tmagritte:
I see. I was under the impression that this was some form of makeshift LUT but it seems that's not how it works. I guess what we really need is true ICC support in Android.
[Nexus 5 General] Tzfardaya:
Absolutely, problem is I don't know how to mash that in... What we have right now is a series of 23/24 numbers for each channel that affect the colour across the range... Yorici has some really good write ups about what affects what, based on current knowledge and experimentation...
[Nexus 5 General] yorici:
I heard some form of color management would come with the next big version of Android, but rumors. The Nexus 7 has an implementation of icc support. It requires custom kernel though.

The parameters don't form a LUT but do have a similar function. The parameters would be like the layer underneath the LUT layer.
[Nexus 5 General] tmagritte:
Well, hopefully rumours are right on this one. It does suggest google is thinking about this, which is good.

Do we know enough to be able to predict the correct parameters from data taken from a PC generated ICC file? If not, do we think we could figure it out by generating ICC profiles using different parameters? I haven't familiarized myself with ICC files or the android parameters yet, but I'd suspect it should be possible, even without a deep understanding of the parameters, to develop a statistical model that would predict the correct parameters given an ICC profile. Of course, that's theoretical. Depending on the complexity the sample size required may make it impractical...
[Nexus 5 General] yorici:
Interesting theory. I don't discard it, but I think it is not the easiest thing. Though we can already create icc profiles, but we can't predict the values enough. We should study them more I am afraid. I know there should be a mathematical logic to it, I just haven't discovered it yet. I'll try tomorrow.

Though I wouldn't immediately count on icc support btw. Perhaps Google just fits in some little sliders for users to fiddle with, or perhaps nothing at all. Rumors remain rumors...
[Nexus 5 General] yorici:
New profile! See second post!
[Nexus 5 General] nexusmaniac:
Loving 'calibrated punch' :D Thanks!
[Nexus 5 General] The Gingerbread Man:
Thanks yorici, updated colour profile zips collection and uploaded to my drive. Going to try it out now
[Nexus 5 General] Chaplan:
So which versions of fku work and which have color troubles?
[Nexus 5 General] yorici:
Just beta 353
[Nexus 5 General] The Gingerbread Man:
I have to give it to you yorici this latest one by you is easily the best my screen has looked and certainly is a keeper. That is until you get round to your next one you detailed in 2nd post. Recommend for all with the 1.8 stock gamma screens. Also to avoid the bug you spoke of within fku I installed the Nexus display control app by Franco again (originally purchased to support his work mostly).

[MENTION=774530]Chaplan[/MENTION] the latest 'stable' fku apk (march 22nd) might not have the bug yorici talked about or you could try the separate stand alone colour apk https://play.google.com/store/apps/details?id=com.nexus4displaycontrol which we know is free of that bug
[Nexus 5 General] galakanokis:
New to this thread, which profile is the latest you mentioned? The one simply labled stock?
[Nexus 5 General] RobbieL811:
I'm fairly new too but from what I have gathered so far it's the profile posted in the second post of this thread. And by the way [MENTION=4809179]yorici[/MENTION], it looks AWESOME! Just found a replacement for my current profile! Thanks!

Sent from my Nexus 5
[Nexus 5 General] galakanokis:
Maybe I read that post wrong but I took that he wasn't running the one outlined in the second post, punchy or whatever it is called. Thought he was running something else.

Going to try it out anyways.
[Nexus 5 General] RobbieL811:
Idk. I'm not sure. I do know that the profile posted in the OP looks good. Check it out.

Sent from my Nexus 5
[Nexus 5 General] galakanokis:
I have a pretty high end Photo Research probe at work, I think I'll dig it out and play with some of these profiles and the color settings. Not something I ever thought about doing on phones.
[Nexus 5 General] sirovai:
Thank you [MENTION=4809179]yorici[/MENTION]! I was waiting for this!
[Nexus 5 General] yorici:
Welcome to this thread!

Stock profile returns you to stock;)

Yorici_Calibrated_Punch is the profile I mentioned in the second post. What do you mean with a probe? I only think of aliens when I hear that:p Do you mean photospectrometer? Or colorimeter perhaps?
[Nexus 5 General] yorici:
Thx! Could you rename yoriciv3 to yoriciv3(old_uncalibrated)? It's a bad profile I made with a spreadsheet in the days I didn't have a colorimeter. I know some people are using it, but this way I clear confusion about what is my real profile. And please delete any yoriciv2's of any kind;)

[MENTION=1363323]vomer[/MENTION] You can upload my profile if you do the same :p
[Nexus 5 General] The Gingerbread Man:
Done and done :)
[Nexus 5 General] danbrown162:
Yorici_Calibrated_Punch... - literally improved my screen 100x. My nexus 5 actually had a good display now! Thank you for all your hard work!
[Nexus 5 General] vomer:
Done Done! [MENTION=4809179]yorici[/MENTION]
[Nexus 5 General] galakanokis:
Ha, no aliens involved at least not this month. Yeah, photo research make photospectrometers. I work in post production so we use them for calibrating movie screens and monitors for color finishing. I have calibrated damn near every screen out there but never a phone. I will change that today. Very cool thread, great detail.
[Nexus 5 General] yorici:
Photospectrometers are awesome but too expensive for me:( The guide I posted in thread will work for photospectrometers too afaik. Though the output value might be different from colorimeters if HCFR doesn't work for you. The principle should be the same though: Measure the RGB value that a parameter adjusts and check if it is what it should be. If you run into problems, please post in this thread ;)
[Nexus 5 General] defffizz:
Flashed franco only to apply this new profile, and it looks amazing, thanks yorici :)

Bright Red Nexus 5, Paranoid Rastakat + franco
[Nexus 5 General] granets:
there's a saying: once you get franco's kernel, you don't go back. :P
[Nexus 5 General] Tzfardaya:
But it doesn't rhyme... So not very catchy... :(
[Nexus 5 General] granets:
that is why franco should make a black edition of his kernel :D
[Nexus 5 General] galakanokis:
Very expensive, this one new is around $35k. I appreciate your directions, I will put them to good use.
[Nexus 5 General] defffizz:
Franco kernel, Iet's be frank, flash it and you'll not go back:D

Bright Red Nexus 5, Paranoid Rastakat
[Nexus 5 General] pm~:
Great work indeed yorici, your new profile is really good! Thanks!
[Nexus 5 General] AGiLiT:
Wow; I'm really impressed with Calibrated Punch! I've been using 0rigin since I first found it, and have never switched; being a firm believer in ""believe the data; not your eyes" and as such trusting in calibration as being the only true way of arriving at a profile. I knew 0rigin not to be perfect, but it had the highest contrast of the initial calibration-based profiles. Compared to 0rigin, the increased contrast in Calibrated Punch is readily apparent and you've done a fantastic job to achieve that level while maintaining the accuracy in the color profile. The whites really pop, but the gradient is still spot on.

The only 'nit' I have about it is the color temperature - it is much cooler than anything I am used to. I hope you manage to bring it down some as you progress (I'm assuming that would be your goal - forgive my presumption if I am wrong.)
[Nexus 5 General] yorici:
No that is the cost for maximum brightness. The Yorici_Calibrated_Accurate profile will have 6500K ct. But that one is harder to build and still in progress.
[Nexus 5 General] AGiLiT:
I'm sure it's thirsty work - Look for a contribution to your beer fund. :laugh:
[Nexus 5 General] yorici:
Thx dude! This will definitely come handy now the Netherlands have won :D
[Nexus 5 General] Bobtehblob:
Awwwww man I came onto xda after the game to take my mind off the loss! At least we gave you a good run for your money, I thought we might have had you there for a minute! [emoji12]
[Nexus 5 General] yorici:
Me2 :p Exciting game it was! But maybe you will kick Spain's ass with 5 - 1 like we did;)
[Nexus 5 General] banny7000:
This calibrated_punch is spot on for me?
[Nexus 5 General] sucsss:
ok. I must be blind.

How do I load the calibrated punch profile in Nexus Display Control App? or is it already loaded when I install the app? I can't find a way to import the txt file.
[Nexus 5 General] yorici:
Have a look at the first post. There is an entire FAQ there explaining everything.
[Nexus 5 General] sucsss:
"

1) Tap 'Load a color profile' (Under color utils in FKU)

2) Select your profile

3) Hit Apply

4) Turn screen off and on to view result*

"

doing that only shows a list of preinstalled profiles.

where would I put the txt file in the 2nd post?
[Nexus 5 General] galaxys:
Same here... It doesn't refresh any new profiles for me...?
[Nexus 5 General] Tzfardaya:
You need to put the newly downloaded profile in the right folder.. It varies depending what app you're using...
[Nexus 5 General] yorici:
I thought this was included in OP, but it wasn't. I'll add it!

FKU: /franco.kernel_updater/color_profiles

NDC: /Nexus_display_control/color_profiles

Faux: /com.teamkang.fauxdisplay/profiles

That pretty much covers it. Extensions don't matter. (you can even remove extension. I had to include .txt to upload to xda)
[Nexus 5 General] blackt5:
Has the values in relation ire been figured out? Example: a ire pattern of 30 equals this value or a ire pattern of 75 equals this value. If we did it would be much easier to calibrate the screen.

That's how I calibrate TVs or monitors, select the value of each ire window and tweak that value to get the measument I'm shooting for.
[Nexus 5 General] yorici:
Good point. I haven't really thought about that, but it's worth an attempt. But don't you need to measure voltages then? My IRE knowledge is a bit behind:p
[Nexus 5 General] Wenzo2:
6500k IMHO di too yellow. You'll make a7500k profile?
[Nexus 5 General] yorici:
6500K first, then I'll see what I will do. It might be more useful to understand the values better in order to calibrate faster.
[Nexus 5 General] Wenzo2:
OK thanks! I appreciate your profile! I think it's the best so far. Maybe too much amoled like. Particularly for black and contrast.
[Nexus 5 General] yorici:
It was aimed to be more saturated and have the highest contrast possible;) But that is what most people like, so I delivered.

7500K has some more probs to it btw

- There are a gazillion options for R, G and B to be 7500 together. I need to find out the regular configuration.

- My colorimeter hasn't been calibrated with a spectrometer. So 7500 might not be 7500K. And that also depends on multiple settings in software..

Therefore it is easier to not pay attention to color temperature and focus on other aspects like contrast and brightness.
[Nexus 5 General] fugn:
Thanks for a great display calibration! Can't wait to see your next project
[Nexus 5 General] simonarturo:
Tried a bunch of profiles and somehow drifted towards your V2 and V3 profiles as they seemed balanced to me. Then found this thread and your Calibrated Punch profile. Needless to say, it is my new profile(until you come up with a new one :D)

As a photographer, I really appreciate the fact you are using a colorimeter and care about correct values. I'm in the process of moving away to Europe but as soon as I'm able, I'll buy you a beer for the good work :good:
[Nexus 5 General] yorici:
Thx dude! Good luck with moving ;)
[Nexus 5 General] blackt5:
No, no voltages. Something like this: open Voodoo Screen Test Patterns, select greyscale and keep pressing next. We probably need more than 11 steps to get it right but can infer the other steps between. I have not tried HFCR to see how it shows results in rgb balance in relation to gamma yet. I usually go with CalMan but I'll look at it soon.
[Nexus 5 General] yorici:
Rgb balance vs gamma? Well they both derive from luminance. I don't really see what those will help us. Please contact me on Hangouts if you have the time!

Yorici@gmail.com
[Nexus 5 General] blackt5:
I'll hit you up later. Its pretty easy, you need to find the rgb balance for each luminance level and raise and lower the group until you achieve the desired luminance level.
[Nexus 5 General] Punkid:
really looking forward to a warmer profile :D 6500K would be fine, but i think something around 7500k would look best :p
[Nexus 5 General] Tzfardaya:
Maybe, but 7500k wouldn't conform to sRGB/D65 standards.... :P
[Nexus 5 General] Punkid:
true true...btw, im not sure if its just me or my ROM (mahdi) or my kernel (franco) OR 4.4.3/4.4.4 , but ive felt recently that the screen has imrpoved slightly WITHOUT the use of any color profile...been using stock profile since 4.4.3 came out and ive really grown fond of the warm colors. Most profiles on the other hand are slightly cooler
[Nexus 5 General] Tzfardaya:
Yeah, most profiles are just people fiddling around... Yorici and only a couple others are actually using colorimeters to test their profiles...

Could be that the glue on your screen has finally cured.. (most new device screens are yellowish because it takes a few weeks for the glue to cure)
[Nexus 5 General] Punkid:
I've had the phone since January, seems unlikely. But the weather here has been REALLY hot for like a month, maybe that did it :P
[Nexus 5 General] Tzfardaya:
Maybe... :P
[Nexus 5 General] Chaplan:
FKU 11.5

FKU 11.5 is out of beta. The beta had a problem with color profiles.

Is this solved on the final build?
[Nexus 5 General] yorici:
Yes, Franco and I fixed that issue. Latest FKU applies and saves profiles correctly now
[Nexus 5 General] yorici:
Anyone with a colorimeter wanting to test the color temperature of my d65 profile? I'm having some doubts.

Hit me up on hangouts: yorici@gmail.com
[Nexus 5 General] Tzfardaya:
Email it to me, I'll test it when I get home tonight.
[Nexus 5 General] yorici:
Repost of post 2!

NEW! Gamma Corrected Brightness (GCB)

Let's do a little experiment shall we? Set your screen's brightness at 0%, 50% and 100% consecutively. Notice something odd? That's right! The 50% doesn't seem like 50%. Why you ask? Well you are not a robot, but a fabulous human that perceives brightness different (i.e:non linear). Well how do you fix this?

We are introducing Gamma Corrected Brightness! This will solve that nasty issue we talked about. Best thing yet, this baby comes with multiple modes and works for every brightness level! And this will save you battery too! With GCB you will have a greater tendency to set a lower brightness than you normally would and that saves battery life!

Four modes are:

-	Stock

-	Gamma 2.0 (Stubborn) – A little bit more stubborn than the natural one for those who need that

-	Gamma 2.2 (Natural)– The natural one that seems normal like it should be!

-	Gamma 3.0 (Nightmode) – This one is for night times ^^

How to use:

1)	Download and install Furnace Kernel

2)	Open terminal

3)	Enter for:

Stock: echo “0” > /sys/module/lm3630_bl/parameters/gamma_correction

Stubborn: echo “1” > /sys/module/lm3630_bl/parameters/gamma_correction

Natural: echo “2” > /sys/module/lm3630_bl/parameters/gamma_correction

Nighttime: echo “3” > /sys/module/lm3630_bl/parameters/gamma_correction

4)	Done!

If you love Gamma Corrected Brightness, please consider to buy [MENTION=4316709]savoca[/MENTION] and [MENTION=4809179]yorici[/MENTION] a drink!
[Nexus 5 General] Technecium:
Sign me up for robot eyes! Is there an option for frickin' laser beams?

I do have a serious question though, is the device actually using 50% brightness?
[Nexus 5 General] yorici:
Yes, but it's using 50% when you push the slider around 70%.
[Nexus 5 General] Technecium:
Ok. I wasn't sure. So 50 isn't 50 in the UI. Thanks
[Nexus 5 General] yorici:
50% is now 50% for your eyes;) not for Androids.
[Nexus 5 General] Tzfardaya:
50% is 50% of the available output, not necessarily 50% apparent intensity...
[Nexus 5 General] yorici:
Stock: 50% is 50% of the available output

GCB: 50% is now 50% of the 100%, but eye based. The 50% really seems like 50%, not like 70%...

(I may understood you wrongly. But this is what is going on)
[Nexus 5 General] Tzfardaya:
It's exactly what I said... :P just different
[Nexus 5 General] Hatshipuh:
There is color space correction in the L release!
[Nexus 5 General] Tzfardaya:
yes, but what type, full ICC support?!?! *hopes hopes hopes hopes hopes*

would make calibrating individual phones so much easier!
[Nexus 5 General] defffizz:
Does that mean that were can expect better calibrated colors with the Android L kernel?

Bright Red Nexus 5
[Nexus 5 General] Tzfardaya:
No idea, will have to wait and see...

And the colors of the n5 are very good when compared to other devices on the market, If a little lacking on contrast. Accuracy is better stock than most.
[Nexus 5 General] defffizz:
Yeah, I know, I read the AnandTech article about n5 calibration, I just hope Google addressed too low gamma / contrast :)
[Nexus 5 General] yorici:
The contrast comes with the overall brightness. This is low to maintain a ~6500K color temperature. So don't expect higher contrast if you are going for 6500K.

Gamma can be fixed of course.