controlling the oled gamut in custom roms - Galaxy S 5 Q&A, Help & Troubleshooting

the stock rom has a couple of different options for screen mode, which allows the native gamut of the oled display to be scaled down to roughly the srgb/rec709 gamut. for instance, see the gs5 evaluation on displaymate
do custom roms have the same feature?
I know that some kernels have color controls, but as far as I am aware, that is just changing the white balance and not affecting the actual gamut.

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The black clipping on the Note is a Software Issue. CONFIRMED! Check this out!

Today,I was playing around with my Note, still worried about the black clipping and blocky videos changing ROM after ROM and didnt find any solution.
Out of curiosiry, I copied the GammaTest image to my PC, went to my display adapter settings, and cranked up the gamma from 1.0(default) to 1.5-1.9 and guess what?
http://imageupload.org/en/file/235342/gamma-normal.jpg.html
The first image shows the gammatest as it should. Here the computer's default gamma is set to 1
I increased my gamma value to 1.5-1.9 and this is the result.
http://www.imageupload.org/en/file/235344/gammahigh.jpg.html
And when setting the gamma to highier values, play all your test videos and images, there will be clipping and blocky pixellation just like you see on the Note. Try this for yourself on your PC.
This clearly shows that the clipping on the note is a software issue rather than a hardware defect and if we could somehow get to tune the gamma on the note, its the END of all the clipping and the horrible video playback.
A point to note is, when increasing gamma values, the images tend to become artificially bright and on reducing them, they tend to get darker. Maybe this explains why the Note produces the best whites as far as AMOLED displays are concerned and seems to be brighter than all the other Galaxy devices which includes, the Galaxy S, S2 and S3.
So the only and truly effective solution is to find a way to tune gamma values under the MDNIE settings and this should be implemented in a kernel. I've seen none so far which is capable of doing this. All CM9 based ROMS have Gamma control disabled under MDNIE settings. This also explains why the same problems were corrected on the Google Nexus with the LEAN Kernel.
This is definitely a GAMMA issue and definitely Software related.
I may be wrong, please do feel free to correct me if so.
Although I do agree (in my non-expert and in this regard completely worthless opinion) it is probably a software issue, this does not confirm whether our Notes' black crush is caused by software or hardware, or if it is fixable. This only means that you can make your display crappy by cranking up the gamma too high. The same result can be achieved in different ways.
I still dont understand the gamma test picture.. Which numbers should be seen? I see 4 to 21 perfectly and can barely see 3.. Should 2 and 3 be seen too?
Sry if I went off topic..
First of all, the image should be quite dark to see in a lit environment and on an ideally calibrated display, the image show a gradual fade to black. So theoritically speaking, on a good display, the left side is barely visible and is seen as a dark gray fading to black.
On the stock ICS kernels, the image is seen upto 4 and then clips to black. If you enable, Force GPU acceleration, you can see upto 1 which means more clipping. On stock GB, you can see all the way to 1. It varies from kernel to kernel.
We just need some way to access the gamma control under MDNIE settings on the Note which is at present, disabled on the CM9 kernel and is not present on any other kernels either.
When you wrote "CONFIRMED" i thought there was some quote from Samsung saying it was a software issue and they were looking into it
I had mailed GSMArena regarding this issue and even after they published it and many other blogs too, Samsung didnt give a damn about it. So I dont think they do now either. The EMMC Bug is more of a fatal issue and to date, even after announcing that they are "working" on a fix, there are none. People are literally bricking from the latest stock when all the other custom kernels have disabled the MMC_CAP_ERASE value from their kernels. So its better not to rely on Samsung for anything. They just sell their phones and thats it. The Note and everything alike are experimental phones and we are their lab rats. They basically only focus on the flagship Galaxy Phone. read GS3 and new ways to sell it.
satishp said:
We just need some way to access the gamma control under MDNIE settings on the Note which is at present, disabled on the CM9 kernel and is not present on any other kernels either.
Click to expand...
Click to collapse
Yeah because we have a unique display that is different from the I9100/I777 - so display tweaks for those won't work on N7000.
Sent from my GT-P7510 using Tapatalk 2
problem
1) Seriously guys, we have to get to the root of this problem. If we can get to the gamma setting on this display we can solve the problem. But how hard can it be to get there?
2) On the other hand, i think that what you did, was change the gamma on an LCD display. As far as I know there are a lot of diferences between LCD and OLED, appart from the fact that we have a pentile display (2 subpixels per pixel, pixels are in RGBG formation) and the LCD uses 3 subpixels per pixel (RGB).
We should join our forces and start on a mission to solve this issue once and for all.
Regards.
It is DEFINITELY a software issue. Try this out: reboot your phone, and while it is still booting and slowish, quickly start the calculator and see the top of the screen perfect and then, for no apparent reason, it gets some kind of a half-circle color spill. Also, when you open the gallery, find a folder with a stock video clip with jelly fish, and when you open that folder, gallery turns to black, and for a half of second it is perfect and then gets sort of color rendering problem. Final test is to start the camera when the night falls, switch to camcorder (for the smoothness), and just look at the screen, it is perfect, no black clipping, and then, as soon as you take the picture, the picture spoils and you get the black clipping- the live image on the screen while observing is totally normal. So, it is 100% SW issue!
I compared my Note to my friend's SIII and the screen is much darker on S3, and images themselves. So, it IS gamma issue. When you open the front camera on the SIII, in a bit darker environment, and look at yourself, you barely see the shape of your head, since gamma is much lower and it only picks up the bright parts, such as your forehead and cheeks. Also, images appear much MUCH darker on the s3 screen than what you see in reality. That is what samsung did to solve the issue: lowered the gamma.
Hope I gave some useful info (no pressure to hit the thanks button )
Cheers
P.S. please, those of you with good screens, post images here of your good note
http://forum.xda-developers.com/showthread.php?t=1801333
shatroghistro said:
It is DEFINITELY a software issue. Try this out: reboot your phone, and while it is still booting and slowish, quickly start the calculator and see the top of the screen perfect and then, for no apparent reason, it gets some kind of a half-circle color spill. Also, when you open the gallery, find a folder with a stock video clip with jelly fish, and when you open that folder, gallery turns to black, and for a half of second it is perfect and then gets sort of color rendering problem. Final test is to start the camera when the night falls, switch to camcorder (for the smoothness), and just look at the screen, it is perfect, no black clipping, and then, as soon as you take the picture, the picture spoils and you get the black clipping- the live image on the screen while observing is totally normal. So, it is 100% SW issue!
I compared my Note to my friend's SIII and the screen is much darker on S3, and images themselves. So, it IS gamma issue. When you open the front camera on the SIII, in a bit darker environment, and look at yourself, you barely see the shape of your head, since gamma is much lower and it only picks up the bright parts, such as your forehead and cheeks. Also, images appear much MUCH darker on the s3 screen than what you see in reality. That is what samsung did to solve the issue: lowered the gamma.
Hope I gave some useful info (no pressure to hit the thanks button )
Cheers
P.S. please, those of you with good screens, post images here of your good note
http://forum.xda-developers.com/showthread.php?t=1801333
Click to expand...
Click to collapse
ok, it is software. good. let's solve it !
It is not that easy..supercurio worked on it for 6 months and then left us hanging... He is not obliged, though..
We need a kernel which can access the gamma control. That is the only 'real' solution for this issue. You are right about the s3 having lower gamma and hence darker images. I've seen this myself and thats why I mentioned on my post that the Note's screen looks brighter due to the heavily cranked up gamma.
Apparently, this might be an issue with pentile amoled. Lower the gamma and lose pure whites for a clipping free darker image like on the Galaxy S or S3 or crank it up and get "richer" looking colours and whiter whites at the cost of extreme clipping in darker shadows.
This is the root of the cause. Improper gamma. Now only if someone who is experienced in developing Kernels would somehow enable gamma control which is present in the MDNIE settings but strangely disabled due to unknown reasons.
I saw that Liquid Black ROM has Gamma Control but didnt try that ROM yet. I really love the Tablet Mode in the Paranoid ROMS. So I want to stick to it while getting a solution.
I tend to agree with satish, it is then a hardware issue that could be remedied partly at cost other colours. I guess I was wrong, I use to think it was only caused by lower quality images, like watching tv on old crt, then watching same on hdtv, that also looks crap lol.
Sent from my GT-N7000 using Tapatalk 2
gbb14 said:
1) Seriously guys, we have to get to the root of this problem. If we can get to the gamma setting on this display we can solve the problem. But how hard can it be to get there?
2) On the other hand, i think that what you did, was change the gamma on an LCD display. As far as I know there are a lot of diferences between LCD and OLED, appart from the fact that we have a pentile display (2 subpixels per pixel, pixels are in RGBG formation) and the LCD uses 3 subpixels per pixel (RGB).
We should join our forces and start on a mission to solve this issue once and for all.
Regards.
Click to expand...
Click to collapse
I wasn't comparing LCD and OLED. I just wanted to prove the point that it is indeed gamma which is set higher on the Note and it is not a hardware issue. I dont know why no kernel for the Note is able to access the gamma control settings. Maybe like Entropy said, the Note's display panel might be a unique design such that any tweak applied on the display may cause unwanted results. As you all know OLEDs have certain hidden characteristics and its more or less like DNA. Every OLED panel is different. So the manufacturer tunes it into the most optimum settings possible on the particular technology used in the panel. But here, Samsung just did it wrong.
If you have noticed, many custom ROMS offer scaling down the brightness even below the default Samsung values and thats when AMOLED's hidden weaknesses start showing up.
In the end, I feel the only solution to this is a Kernel which enables the Gamma Control or somehow enabling the Gamma Control in CM9 which is currently disabled in most CM9 based ROMS.
baz77 said:
I tend to agree with satish, it is then a hardware issue that could be remedied partly at cost other colours. I guess I was wrong, I use to think it was only caused by lower quality images, like watching tv on old crt, then watching same on hdtv, that also looks crap lol.
Sent from my GT-N7000 using Tapatalk 2
Click to expand...
Click to collapse
Not exactly a hardware "issue" but maybe more like a hardware "limitation" of "Pentile" AMOLED. Samsung has hidden this issue in the Original Galaxy S and in the Galaxy S3 by lowering the gamma which results in darker images but "NO" or "Invisible" clipping hence satisfying consumers. Due to the lower Gamma on those phones, darker shadows seem to blend into eachother hence we dont see any clipping as darks are "Dark". And hence, when consumers dont "see" any artefacts, banding or clipping on their videos and images, they are satisfied. But this is at the cost of "dull" whites or artificial whites and lower overall perceived brightness.
As the Note has its Gamma cranked up, White looks white. I may even go forward and say that the Note produces the best whites ever seen on any AMOLED panel. Hence web browsing looks richer, colours look richer and the overall perceived brightness is again higher than other devices, But this again comes at the cost of clipping in darker shadows and hence poor looking videos and images, blocky pixellation,etc
So in the end, everyone is ready to sacrifice their "whites" for a clipping free display. Thats how it works out for consumers. As long as they dont "see" the problem, they believe its not there. So this may be a limitation of "Pentile" AMOLED and lowering the gamma may be Samsung's way of hiding the weakness.
The Galaxy S2 has an overall best screen which I've seen and thats due to the RGB AMOLED Technology. Colours look richer, the percieved brightness is higher and no clipping either. Thereby best of both worlds.
gamma
1) I saw some minor fixes on this thread http://forum.xda-developers.com/showthread.php?t=1715416 but nothing really gets deep down to the problem. Those fixes are actually some kind of effects, they aren't so good. They talk there about some kernels that helps the black clipping issue.
2)I have found an apk that is called voodoo display filter, can you check it out? it does seem to enhance the black.
3)As i was playing around with the screen settings on cm9, i noticed that if i set the screen scenario to VT, the mode to MOVIE, and the outdoor mode to ON, i can see down to number 4 on the gamma test image (usually with the default settings i can see everything down to 1).
regards
gbb14 said:
1) I saw some minor fixes on this thread http://forum.xda-developers.com/showthread.php?t=1715416 but nothing really gets deep down to the problem. Those fixes are actually some kind of effects, they aren't so good. They talk there about some kernels that helps the black clipping issue.
2)I have found an apk that is called voodoo display filter, can you check it out? it does seem to enhance the black.
3)As i was playing around with the screen settings on cm9, i noticed that if i set the screen scenario to VT, the mode to MOVIE, and the outdoor mode to ON, i can see down to number 4 on the gamma test image (usually with the default settings i can see everything down to 1).
regards
Click to expand...
Click to collapse
You are talking about the screen adjuster app which in my opinion is neither a fix nor a workaround for the problem. It destroys the blacks and uses the screen out of specification.
I have searched everywhere but couldnt find the apk for vodoo screen tuning. So, couldnt try that.
Anyways, this issue cannot be resolved with an app but only a kernel which supports gamma control.
You can find the app on bazaar android, i think it was made by super mario super curio, or something who used to work on this issue, and had a thread of over 50 pages, until he decided to quit the work because of flamers and stupid people.
I've had some ideas:
Can the devs add some new settings under cm9>settings>advanced>screen>mode ? ooooor instead of bumping the gamma on outdoor mode, to lower it?
regards
Op please change thread title, as it is hardware.
Sent from my GT-N7000 using Tapatalk 2

Is it me or do custom color kernels improve side view?

Is the viewing angle drastically improved in custom roms, for instance paranoid android? I feel as if the color is much better from the side, much less of a color change. Or is it me not wanting to see it after flashing?
shadehh said:
Is the viewing angle drastically improved in custom roms, for instance paranoid android? I feel as if the color is much better from the side, much less of a color change. Or is it me not wanting to see it after flashing?
Click to expand...
Click to collapse
With custom kernel , you can control color tuning and gamma setting which makes it look better... but viewing angle???
I think is something related to our sight, for istance I like the droidmeup_puncy colors from faux display, but with stock one i've better angle view,
maybe is related to saturation or contrast or whatever involving our eyes

What is Srgb ? And why should I use

People were talking about Srgb in the nexus 6p .. I tried it and the colors looked weird to me. Why would I use this feature ?
sRGB is a method of rendering colors to which the colors drawn are, in a sense, more basic and more true to the central RGB color matrix. Newer display technology is capable of rendering a wider range of colors which can increase saturation and give things a more "popping" visual as they are "truer than life". Using the sRGB setting will tone down those exaggerated colors and bring them closer to what you would see in the real world. I doubt you would see much if any performance impact be it positive or negative to the processor or battery since the technology being used can handle these varieties of colors easily. So if you find your screen to be more appealing in sRGB mode as you like LCD-like visuals versus the heavily saturated Samsung-like AMOLEDs, then you may benefit from using it. In a real-world application, I can see it being useful for seeing how your photos would really display on print or a standard LCD screen as it is reducing the range of colors and saturation created artificially by screen enhancements.

CF Lumen/Twilight and AMOLED screens

I am a big user of cf lumen/twilight/flux on all my devices. However, I came across a comment stating that devices operating on AMOLED screens should not be using cf lumen or twilight as this causes accelerated degradation or 'burn in' of the pixels.
Is this true? or is it just overblown?. I came across a few articles that stated the same thing, AMOLED and CF lumen/twilight = bad.
I'd like to know as well, since I'm a fairly heavy user of Twilight on my Motorola.
I'm also use amoled screen and as i know twilight really bad-it set 'filter' with constant color on the screen, but in cf.lumen (if you have kernel that supports it) you can set work mode to KCAL and cf.lumen will simply change RGB colors, without any filter and so image will not constant and pixels not burned. If i'm not right, please say)

What can this thing do..

I wonder if the shield can, through a custom kernel, adjust rgb, gamma, or color calibration. similar to a nexus 6p with a custom kernel like franco or elementalx i can adjust to a much cooler screen similar to the galaxy series.
Also I saw in the shields display settings there is a dynamic range setting which i changed to full and the screen seemed to have dramatically changed. the darks seemed much darker. i dont have an hdr tv but a sony bravia about 2 yo so i didnt think it was actually hdr but only the output from the shield.
dontbeweakvato said:
I wonder if the shield can, through a custom kernel, adjust rgb, gamma, or color calibration. similar to a nexus 6p with a custom kernel like franco or elementalx i can adjust to a much cooler screen similar to the galaxy series.
Also I saw in the shields display settings there is a dynamic range setting which i changed to full and the screen seemed to have dramatically changed. the darks seemed much darker. i dont have an hdr tv but a sony bravia about 2 yo so i didnt think it was actually hdr but only the output from the shield.
Click to expand...
Click to collapse
full vs limited is in the range that the device will output colors to the screen. with limited the normal range of 0-255 values per color is limited to 16-235. (256 values per color ^3 equals 16,7million colors (3 colors: RGB)
most particularly (older) tv's won't process the full amount of 16,7m colors, in comparison to monitors which almost always do. Reason why is probably cost, to make them cheap, and to save bandwidth. So they compressed the output, losing some of the detail in between (more like MP3 in comparison to using 160kbps vs 320kbps mp3's, most people won;t notice the difference, but it is there unconsciously)
Anyway. by compressing the range, the tv then stretches these out so that those values become the new white and black. Else everything would look greyish and faded. But now you have less detail because you miss some information, because some of the gradient is missing.
Your TV is set up to the limited range, so that it stretches those to be the new black and white. But when you switch the incoming signal to the full 256 range, the tv will still stretch these as if they were the limited range, and it basically cuts off black and white information, making everything higher contrast but losing a lot of information because it's cut off. And then you'll have to set your TV to full as well, but that's not always possible. Because most tv's can't process more color information.
That's why HDR is such a big improvement, more color information, more visible dark and bright gradients and the overall brightness contrast is wider.
But I think in your case by setting it to full you will get the feeling of more contrast, but essentially you are cutting off a bunch of information. You'll probably notice in dark scenes that you can't see much, because it's clipped out.
If this makes sense to you. (I may have made some mistakes explaining this)
Regarding calibration, you should calibrate your tv in stead. There's no use in calibrating your shield. That's only necessary if you can't control your screen, which TV's can, but phones can't. So mess around with your tv color settings.

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