Heads up for anyone thinking about getting an iPhone 14 Pro

[JohnZeman]

Yesterday I bought a new cell phone, an iPhone 14 Pro.  The reason I bought it is because I'd read its camera takes some very good photos.  It can also shoot photos up to 48MP in size.

And it does take very good photos for a cell phone however I've also learned that when I shoot in 48MP mode I end up with duplicated metadata problems after I've done a writeback with IMatch.  So far only the original DNG from the cell phone seems to have the problem.

This is just a heads up for anyone thinking about getting an iPhone 14 Pro cell phone so they can shoot in 48mp mode.  Things seem to be ok in the standard 12mp shooting modes.

[Mario]

What do you mean by "duplicated" metadata? Which metadata did ExifTool duplicate?
DNG files usually contain EXIF data, sometimes GPS data and embedded XMP metadata.

Maybe provide a SOOC image as taken by the phone for download (or send it to support email address) so I can write some metadata to it and see what the outcome is?
DNG files usually make very little problems, metadata-wise. But a) Apple and b) Apple...

[JohnZeman]

Mario I just stepped outside and took a 48mp ProRaw photo with the iPhone 14 Pro cell phone camera app.

It's been a long time since I've tried to create a shared link for someone to download large files, hopefully the link below will take you to the file I just uploaded.

https://1drv.ms/u/s!Atck8IqFtmUwgaZPCNP_rjCg8DiK0w?e=RghLZQ

Once you have it as you enter metadata and do a writeback afterwards look at the description and copyright fields after doing the writeback.  For me those fields will then show the correct metadata I entered followed by a semicolon ( and then the same metadata will be repeated a second time.

[mopperle]

John, I can confirm this behaviour with your file:

After adding the file to the database:
 

After adding Metadata:


After writing back the metadata:

[JohnZeman]

Thank you for doing that mopperle.

[Mario]

I have downloaded the file and analyzed the problem. I can reproduce it here.
Please keep the file in your cloud space for analysis. See below.

The image file contains a rudimentary XMP record with three tags:

Code Select Expand

[XMP-x]         XMP Toolkit                     : XMP Core 6.0.0
[XMP-semanticSegmentationMatte] Semantic Segmentation Matte Version: 65536
[XMP-apdi]      Auxiliary Image Type            : urn:com:apple:photo:2020:aux:semanticskymatte
When I change the headline to "IMatch" and write back, the XMP record in the file is duplicated and the XMP headline tag exists twice afterwards. This appears to be an ExifTool issue.

When I first delete the existing XMP record using the ExifTool Command Processor preset "Delete XMP Metadata" (nothing of value is lost in this case) and then change metadata and let IMatch write back, the duplication does not happen! I can change metadata any number of times without metadata getting duplicated.

I assume that something in the partial XMP record written by Apple, in conjunction how IMatch writes metadata somehow confuses ExifTool in this case and causes the duplication.

I will report this in the ExifTool community and see what we can find out.

Tip: If you run the "Delete XMP Metadata" preset in the ECP on these files, IMatch works correctly afterwards and you can enter and write-back metadata.

[JohnZeman]

Deleting the XMP metadata did solve the problem Mario, thank you!

[Mario]

This is indeed a problem caused by Apple.
The phone write an invalid XMP record, and this causes ExifTool to duplicate the XMP data during writing. See this thread in the ExifTool community for more details: https://exiftool.org/forum/index.php?topic=14218

There is not really something I can do from the IMatch side, not without risking causing issues for all other users who don't have to deal with iPhone 14 files with invalid XMP metadata.

This reminds me of the face regions some Apple phones write into the XMP, with both width and height always being 0.
Apple software deals with this silently, but you run into trouble once you dare to leave the Apple world and open your images in another software which understands XMP face regions.

IMatch contains a work-around for this Apple bug. I see these files in the wild still today, so probably Apple has never fixed it.
I don't have Apple products. But maybe you can tell them that the XMP this phone writes is non-standard and incomplete and will mess up workflows everywhere?

[mopperle]

Apple will take care a shit about it. And that's the reason why I am on the move away from Apple.