iOS 13.1.2 metions this line on the changelog
Fixes a bug that could result in a loss of display calibration data
iPhone X
You can't. If this is a problem to you make a Genius Bar appointment an talk to them about replacing your iPhone. But again, I don't believe the data you are referring to you (which is burned into the graphics IC and screen) is what this bug is about.
It is system data that has to be available in order for you your screen to calibrate brightness, contrast, changes in background etc. It is solely used by the screen itself, it is not transferred from your iPhone and for anyone to retrieve it they would have to know how to dump the logs and then know how to read them and know the state of your environment when they changed. Notice it said "could".
deggie wrote:
It is system data that has to be available in order for you your screen to calibrate brightness, contrast, changes in background etc. It is solely used by the screen itself, it is not transferred from your iPhone and for anyone to retrieve it they would have to know how to dump the logs and then know how to read them and know the state of your environment when they changed. Notice it said "could".
Hi, I understand it's system data for colour accuracy, also called ICC/ICM files on Windows, macOS, Linux etc. I work in image processing for colour sensitive photography.
My concern is the potential loss of colour accuracy. And the bug fix mentioned it "could" delete the display calibration data.
If it was lost, how can we know for sure? If it was confirmed to be deleted, how could we get it back?
The bug does not involve any of that and is not data that was placed on the iPhone. You would know if you lost it as your iPhone display would have serious issues. If it did you could make a Genius Bar appointment and get it replaced.
deggie wrote:
If this is a problem to you make a Genius Bar appointment
The nearest AASP is 100+ KM away from me.
I don't believe the data you are referring to you (which is burned into the graphics IC and screen) is what this bug is about.
Can we get some kind of confirmation on this? What exactly was this bug about? Is it possible it somehow altered data inside the IC which I'm assuming to be highly unlikely since that's a ROM.
This is a user-to-user technical support site. I would suggest you call AppleCare and immediately asked to be transferred to a Tier 2 support person. Apple is extremely secretive so be ready for them to not give you certain information. They will not give you more details about what the bug was about so you can skip that question.
deggie wrote:
This is a user-to-user technical support site. I would suggest you call AppleCare and immediately asked to be transferred to a Tier 2 support person. Apple is extremely secretive so be ready for them to not give you certain information. They will not give you more details about what the bug was about so you can skip that question.
I did start this case with AppleCare, they told me that genereally when data is lost, it's gone for good. But the advisor was unable to confirm regarding the state of the display calibration data, wether the bug simply deleted it from memory (RAM) temporarily or wether it wiped the data clean from its storage source. He was unable to confirm if the display calibration data for every panel was actually stored on Apple's servers, which I find unlikely.
He suggested me to start a thread on discussions.apple.com and see if I could get extra information here.
THIS is exactly what we need to find out; perhaps the best way to frame the question to them would be to ask if the calibration they’re talking about refers to the (auto-)brightness/True Tone/Night Mode/etc settings. If so, we should be safe, since we could infer that it’s a problem reading/writing a .plist file kept in user-space storage. If not, then that COULD be problematic, since it’d mean it’s potentially lost data that’s on the display’s flash-ROM, or at the very least, data stored inside /dev/, or some other user-inaccessible space.
If it’s the latter, what I’m hoping is that iOS <13.1.2 is simply UNABLE to read the display’s calibration ROM, and by updating the OS, it fixes this inability and then it’s able to resume reading its previous calibration data.
How can we know if we lost display calibration data?
The human eye cannot accurately measure colour accuracy aka Delta E value like a colorimeter can.
I've talked with the other iOS techs at work, and all that can be done is that we make a report... We've never seen much response unfortunately, it's not like they listen to their techs any more than the general public/these boards/crash reports sent by your devices.
Dark_Nate wrote:
How do we get this thread to be taken seriously by Apple?
You don't. Apple is not reading here. You can submit feedback here:
Or, you can contact support using the link at the top right of every page of these forums.
However, as deggie noted above, you're unlikely to get any information on this.
Essentially, if they see enough issues coming back in the logs returned to them by the millions of devices out there, THEN they take action...so, we basically need more people opting-in/not opting-out from "returning system and crash logs to Apple". The logs don't contain ANYTHING that could identify you or what you were doing, any more than those engine diagnostics on your car could tell your mechanic who's houses you've been driving to and what music you were listening to while you were driving there...
EDIT: Let me be clear, even that is a LONG shot on getting them to respond to ANYTHING, and no matter what, don't expect it to be quick...this is more of a general statement than advice on how to get them to respond to the screen calibration issue...
They found a bug, fixed it. They know exactly how it works and when. They just need to clarify about this display calibration data loss situation.
Perhaos sinebody famous could tweet this thread to Apple.
How do we get this thread to be taken seriously by Apple?
Already told you. Apple support told me to come here in the first place.
What exactly happened/happens with the display calibration data on iOS 13?
