Question about some warnings

[andiandi]

Hi,

I used the following line to write filename to image description :

exiftool "-Imagedescription<filename" path

and I got these four warnings for some images :

Warning: Invalid CanonAFInfo data

Warning: [minor] Fixed incorrect URI for xmlns:MicrosoftPhoto

Warning: [minor] Maker notes could not be parsed

Warning: IPTCDigest is not current. XMP may be out of sync


I would like to know if this can cause some issues or if it can change/corrupt something, or if I can/should ignore this ?

[StarGeek]

Warning: [minor] Fixed incorrect URI for xmlns:MicrosoftPhoto

You can completely ignore this. It won't affect how any program reads the data.  At some point, Microsoft changed how they wrote the URI in Microsoft XMP tags. The difference is simply a extra slash.  I believe it originally was
xmlns:MicrosoftPhoto='http://ns.microsoft.com/photo/1.0/'
and then Microsoft changed it to
xmlns:MicrosoftPhoto='http://ns.microsoft.com/photo/1.0'

Warning: IPTCDigest is not current. XMP may be out of sync

This means there's a Photoshop:IPTCDigest tag in the file and it does not match the data in the file. From the notes on the IPTCDigest entry on the Photoshop tags page
     this tag indicates provides a way for XMP-aware applications to indicate that the XMP is synchronized with the IPTC.
I believe the idea is that if the XMP data and the IPTC IIM data are out of sync, then the program is supposed to give the IPTC data priority.

If you want, you can make sure the IPTC data and the XMP data are in sync and then run
exiftool -IPTCDigest=new file.jpg
to update the digest.

Personally, I just remove this tag.  It's extra work to keep it up to date with little return for the work.

Warning: Invalid CanonAFInfo data

Warning: [minor] Maker notes could not be parsed

The CanonAFInfo warning indicates there there's a problem with the Canon autofocus data.  This along with the MakerNotes warning indicate that the Canon MakerNotes data in the file has probably been corrupted.  This can happen when a poorly written program tries to edit the metadata of a file.  If the file is a RAW file, such as a CR2, then there might be some problems but for a jpeg, it shouldn't affect anything.

[andiandi]

Alright thanks, it should be OK for my case.

[wywh]

Personally, I just remove this tag.  It's extra work to keep it up to date with little return for the work.

You meant the IPTCDigest tag, right?

That Photoshop:IPTCDigest tag seems to cause potential date errors in some apps so I am considering removing it to be future-proof.

(For some strange reason not all .jpg files having different Photoshop:IPTCDigest vs File:CurrentIPTCDigest have that date error in misbehaving apps. And it seems that at least iOS .jpg files do not have either tag at all. Maybe the old Lightroom 6.14 or some step in my workflow is the root of this error.)

https://exiftool.org/forum/index.php?topic=13437.msg72551

Anyway, although currently all my .jpg files seem to display a correct date I plan to fix them:

1. Backup and move all images with such warning to a folder:

exiftool '-Directory=./Warning' -if '$ExifTool:Warning' .

2. Then nuke the Photoshop:IPTCDigest from all .jpg files in that folder:

exiftool -m -P -overwrite_original_in_place -Photoshop:IPTCDigest= .

Question: does that sound reasonable?

I also tried to delete File:CurrentIPTCDigest but somehow it does not succeed:

exiftool -CurrentIPTCDigest= .
Warning: Sorry, CurrentIPTCDigest is not writable

- Matti

[StarGeek]

You meant the IPTCDigest tag, right?

Yes, sorry if I wasn't clear on that.

(For some strange reason not all .jpg files having different Photoshop:IPTCDigest vs File:CurrentIPTCDigest have that date error in misbehaving apps. And it seems that at least iOS .jpg files do not have either tag at all. Maybe the old Lightroom 6.14 or some step in my workflow is the root of this error.)

Lightroom is probably adding it.  Or some other similar image management program

Question: does that sound reasonable?

Yes, though I just remove it in place.
exiftool -if "$IPTCDigest" -IPTCDigest= /path/to/files/

If I could, I would drop using IPTC IIM data altogether, but my image viewer of choice doesn't support XMP, even though it's been requested for over a decade.

I also tried to delete File:CurrentIPTCDigest but somehow it does not succeed:

That's because it doesn't actually exist in the file.  It's calculated on the fly.  It's there simply to compare to IPTCDigest.  Most of the File group tags aren't deletable.

[Phil Harvey]

Re IPTCDigest...

The MWG recommendation is to ignore the XMP if the IPTCDigest exists and does not match the CurrentIPTCDigest.  So it is probably best to delete IPTCDigest in most cases.

- Phil