Help- Artifacts/Corruption in several Photos

Same problem here on Mojave 10.14.1 (18B75). I took some pictures yesterdag on a family party. When I preview them in Finder with Quick Look the artifacts are most apparent with HEIC images. I've found the following:

1. Export on Mac from Photos HEIC to JPG results in pictures with screen artifacts
2. Exporting to a different image format (I tried TIFF) there are no artifacts
3. "Export Unmodified Original..." also results in pictures with artifacts
4. Sometimes the artifacts disappear when peviewing them again with Quick Look (cursor up/down in a list of pictures)
5. Artifacts appear top and left side and bottom and right side of the image

I use a Mac Pro 5,1 with an Nvidia GTX680 Mac edition video card with standard macOS drivers.

Interesting, I should have tried this first, by booting into safe mode, the issue does NOT happen.

Safe Mode disables accelerated graphics. Perhaps all of you who are seeing this problem should compare the models of the graphics cards.

If it is not the graphics card - safe Mode also disables these features: Use safe mode to isolate issues with your Mac - Apple Support

• Verifies your startup disk and attempts to repair directory issues, if needed
• Loads only required kernel extensions
• Prevents startup items and login items from opening automatically
• Disables user-installed fonts
• Deletes font caches, kernel cache, and other system cache files

So it would be good to check the kernel extensions and startup items installed by older software.

I have the same exact issue but different artifacts. Those artifacts appear simply even when previewing photos using only Finder by pressing space bar on the image in Finder. Opening them in Preview also shows the artifacts. Sometimes when I move back to the same photo, the artifacts disappear...

The interesting point is that in your original photo on the left, you can almost make a pattern that is represented by the artifacts on the right...

I ran diagnostics on my iMac (OK), then decided to erase my SSD, and reinstall Mojave fresh, the issue persists. I opened a bug report with Apple, which I recommend you do too at bugreport.apple.com (you need a free dev account)

I am stumped as I cannot edit any of my images, I will check if the issue happens with non HEIC photos.

iPhone X , iOS12, HEIC format

MacOS Mojave 10.14

iMac (Late 2013), 3.5Ghz/i7, 24Gb/1Tb SSD

Thanks for double checking at least we are having some common points. As a matter of fact, you do not need to use any editing software, just simply in Finder, using the "space bar" to display the image should show the artifacts. Sometimes opening them in Preview would still have that artifact and sometimes it goes away...

Can you and any other user having this issue please list your OS, Mac hardware attributes ? (Apple Logo top left -> About this Mac)

Bonjour Léonie,

1- HEIC Photos on iPhone X are clean

2- Artifacts only appear after transfer to Mac

3- Boom, very good suggestion, I converted the clean JPG w Preview to HEIC and voila artifact ! Please see attached screenshot.

I generated the kernel extension list in safe and normal mode and running some commands to compare, although that will only confirm what you said above, that the advanced graphics drivers are NOT loaded in safe mode.

I can dig some memory test tools and run it, too bad we don't have access to Apple's extended diagnostics 😉

As I posted earlier, my graphics card is different (on my MacBook Pro):

I will check my iMac later. I did not yet upgrade it to Mojave, but it is using the same iCloud Photo Library with plenty of HEIC images.

YES 😉 No artifacts previewing HEIC photos on 10.13 High Sierra on my same iMac! it took two hours to restore but at least now we have some data. I have been updating my bug report 45249451 that has not yet been acknowledged, maybe @léonie you can pull some strings ?

I'll keep my iMac on High Sierra in case someone has some ideas to collect some logs and revert back end of day.

PS: If anyone is on Mojave Beta, they can open a bug report using Feedback, and maybe it gets some traction?

My High Sierra iMac:

No problems at all with HEIC images. The models are similar, but the processor is different.

I need to keep this Mac on High Sierra, because I do not want to lose the ability to create photo books in Photos. S I cannot test, if this mac would be showing the same problems on Mojave.

My Mojave iMac

has the very same problems described here. I only noticed after upgrading to Mojave, consistent with what's been posted above. I first noticed the issue when trying to send heic images from Photos using either Mail or Messages. It took a while to find other users with this issue, so I agree that it's likely a somewhat rare 'bad combination' of Mojave and older iMac configurations. Kind of a drag. Not a problem with images recently processed through Photos using other cameras (non HEIC images) or older jpeg images from my iPhone.

I really don't want to back install 10.13 as there is much I appreciate about Mojave in conjunction with the latest iOS. For now, I've simply adjusted my iPhone to format images as jpgs. But I'm not sure what's the best solution for the many hundreds of heic images accumulated on Photos before my recent upgrade to Mojave, and before I realized the issue.

Thanks for everyone's hard work sorting this out.

I took some photos with an iPhone 8 Plus and it's annoying that all photos i exported from "Photos" contain the same artefacts... I took a look on the original photo in the Library. Opening it with Quicklook you can see the (in this case) green artefacts. When opening it with "Preview" everything seems to be fine.

Seen on macOS 10.14.1

The file type ist HEIC...

Interesting, I should have tried this first before erasing my SSD, by booting into safe mode, the issue does NOT happen. Then when I restarted in normal mode, boom artifacts all over those iPhoneX HEIC pics... I'll take a look in the massive logs to find something.

Anyone can support a detail bug report using the Developer bug reporter, if they sign up for a free developer account.wed to really need to be developers to use this utility. The feedback form is not really useful to send a detailed bug report, see:

https://discussions.apple.com/docs/DOC-7641

I saw the update to macOS 10.14.2, when I went to System Preferences > Software Update. The App Store does no longer show the System Software updates, only the application updates.

Or try the Combo Update from Support page:

Download macOS Mojave 10.14.2 Combo Update

Thank you for the reply. As mentioned above, I erased my SSD, re-installed Mojave fresh, then re-did the test, so there is no additional software installed aside from Apple's.

Graphics Card: NVIDIA GeForce GTX 775M 2048 MB

Apple's diagnostic test (pressing D) doesn't show any issues, I know Apple store tech's have a more extended one but diagnosing Graphics card issue is tough.

And voila, I believe I found something, its HEIC vs JPG... OP, please try switching on your iPhone X to Compatible mode which will create photos in JPG format. I have taken two photos just now and recorded the video as I am switching between the HEIC and JPG photo in Finder. The JPG photo exhibits no artifacts while the HEIC does.

Now that does NOT explain why this issue does not happen with many other HEIC users so there must be something still to do with the Mac 😕

My card is different:

AMD Radeon R9 M370X 2048 MB

Intel Iris Pro 1536 MB

It may be the combination of a certain graphics card with the HEIC compression.

Both JPEGs and HEIC images have a lossy compression, but the algorithms are different, and they will give different artifacts, if some bits of the image get modified due to faulty memory modules or problems with the graphics card. That you are only seeing the artifacts in normal mode points to the hardware, if your Mac software is still squeaky clean after the clean install.

If your HEIC photos have all been taken on the iPhone, you may want to check them, while they are still on the iPhone. Are you seeing the same corruption, if you are zooming in on the photo on the iPhone? Before it has ever been touched by the Mac? Or do the artifacts only appear after transferring the photo to the Mac?

As a further test: You could try to convert a JPEG that is fine to a HEIC file on your Mac. Preview can export in the HEIC format.