Author Title will be shorten in version

[Rene Toepfer]

How can I switch off that the Author Title at IPTC Metadata will be shorten in JPG which is a version? I have a DNG as master (detailed settings see attachements). The Author Title in DNG is empty but in JPG, exported from Capture1, it is correct and has a length of 40 characters. If I change, e.g. keyword, at the DNG and propagate it to the files (menu: Commands|Meta-Date write back|For selected files), the Author Title gets shorten to 32 characters.


I have no Metadata template used neither for DNG nor JPG.

[Mario]

Do you still rely on the legacy IM3 IPTC format? That was declared as discontinued 15 years ago.
When I recall the old stuff correctly, the author has a length limit of 32 characters?

If you fill in metadata which exceeds the length limits in legacy IPTC, clipping will occur. In the IPTC data and, when IMatch is forced the reload the file for some reason, also during ingest (not after normal write-back).
If you must support IM3 IPTC in your files, you must stay within the limits of that legacy format. It was abandoned 15 years ago for good reasons...

I recommend you remove the legacy IPTC metadata from the file (there is an ExifTool Command Processor preset for that). I, and I'm sure many users, did that 10 years ago and never looked back.

[Rene Toepfer]

Thanks for your explanation, than I do not have to look more in detail for a mistake by me. I am talking about IPTC Metadata:Creator (Item 4 in your Metadata Pulldown).


Meanwhile I have tested with Metadate template (ore manual) and a length of more than 32 characters is not an issue (I used 40 characters for testing). It will be also exported into JPG and shown correctly with exiftool.

[Mario]

Does the target file contain legacy IPTC metadata (there is also modern IPTC/IPTCExt data in XMP which has no length limits at all).

[Rene Toepfer]

If the JPG is exported from C1, it has more than 32 characters in Author Title. I have checked it with exiftool.

[Mario]

Legacy IPTC or XMP IPTC?
The author can have a maximum of 32 characters in legacy IPTC (See: https://de.wikipedia.org/wiki/IPTC-IIM-Standard, at the bottom)

[Rene Toepfer]

If I export an image from Capture1 the characters at "Authors Position" (so it is called in Exiftool and shown at the bottom of the command line) exceeds 32, see attachements 2021-02-21_10-39-23__dsc07243__2k_ohne_logo_5.jpg and 2021-03-18_12-00-10.png. Therefore, I assume it is XMP IPTC. In IMatch it is called "Author Title". If I do as per my initial post, IMatch shorts it to 32 characters - even it shows more then 32 characters directly afterwards importing them.

[Mario]

Use the -G1 switch to show the tag name. A bare untagged field list does not explain anything.
Also, ZIP images before uploading. The community software re-encodes all uploaded images and usually strips metadata. I will look at the file once you did it.

You can save us all a bit of time.
You can tell yourself if the file has legacy IPTC data via the "List Metadata" template in the ExifTool Command Processor or by just running the Metadata Analyst app on the file.

The ExifTool Command Processor
The Metadata Analyst

It is not uncommon for other software to don't apply the limits required by the old IPTC standard. Many don't care.

If the file has legacy IIM3 IPTC data, my first reply from above applies.

[Rene Toepfer]

Thanks for taking care of this issue!
If I run exiftool with -g1 switch it prompts "Authors position" in full length is in XMP-photoshop:Authors Position and the short version in IPTC:By-line Title. The ExifTool Command Processor prompts the same. The output of the exiftool I have enclosed as TXT in the ZIP too.

IPTC:By-line Title: 12345678901234567890123456789012
XMP-photoshop:Authors Position: 1234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890

[Mario]

So, your file contains legacy IPTC data.
It you must keep it for some reasons, you need to respect the limits. IMatch has to migrate metadata between XMP and legacy IPTC.

As I said in my very first post above and explained many times in this community over the years, best solution is to get rid of legacy IPTC. It has been discontinued 15 years ago. Applications don't create it anymore. IMatch maintains it when it finds it, but the limits apply.
Your author tag will be shortened by ExifTool to the allowed 32 char limit. And when IMatch has to map the legacy IPTC data back to XMP when it some some reason has to re-ingest the file, the 32 chars will be mapped back to XMP.

Either get rid of the legacy data or disable MWG-compliance in IMatch. IMatch then no longer maps between EXIF/GPS/IPTC and XMP.

[Rene Toepfer]

Thanks for your support with this query.
C1 writes Legacy IPTC in parallel to XMP and Legacy IPTC cannot be switched off. I have followed and tested your advice to delete the legacy IPTC afterwards exporting from C1. Now everything works as expected.

[Mario]

As per the official rules and recommendations of the IPTC committy: Applications MUST not create legacy IPTC data anymore. Applications SHOULD maintain/update existing legacy IPTC if found in an image.
This is what IMatch has implemented.