Question about the Pending Metadata Write-back collection

[DavidOfMA]

My database has about 8,000 images in the Pending Metadata Write-back collection. In each case I checked, what IMatch wants to write is XMP::Lightroom\HierarchicalSubject.

Where did this come from? I don't even use Lightroom, and I haven't done anything to these files that I can think of that would create metadata. If this metadata tag is irrelevant, can I purge the Pending Metadata Write-back collection?

Thanks,
David

[jch2103]

Short answer (I'm writing from my tablet): this tag is part of Metadata Working Group compliance. You'll find the tag useful in dealing with hierarchical keywords,  etc.  IM5 uses it for handling keywords. I'd definitely counsel against deleting contents.

[DavidOfMA]

Okay. What's puzzling, then, is why only 8,000 of the 100,000 image files in my database have this pending metadata.

[Mario]

IMatch stores hierarchical keywords in this tag. Please see the IMatch help on keywords for details.
When IMatch imports a file, it will update/create this tag by importing existing legacy IPTC/XMP keywords, using your Edit > Preferences > Metadata settings and your thesaurus. If this causes a change in existing hierarchical Keywords, the file will be marked as pending write-back. Else not.

[DavidOfMA]

Ah, that explains the 8,000 files with pending metadata. I must have IPTC information in them that was converted on import into IMatch 5. I'd prefer to keep the XMP data in sidecar files and have been unable to find a way to globally specify that in IMatch 5, though I see that it's possible to specify it for each file extension individually. Is there a way to specify globally that I want to use sidecar files? Or, is that now a bad idea? 

[Erik]

I'm not sure it's a great idea, but ultimately it depends on what software you use outside of IM.  For instance, some software may never look at a sidecar file for a JPG file, even if it's there and you have kept XMP out of the JPG to begin with.  There are a lot of threads about sidecar use.

It does look like you may have to specify sidecars by extension for files that commonly use embedded XMP data.  However, it should be a one time effort, and it can be confined to the formats that are relevant to you and only those that typically have XMP embedded.

I would strongly urge reading the help file on the Metadata 2 panel as there are a lot of relevant cautions there because it does open up a possibility of having XMP records in XMP files AND embedded do to other software writing XMP or what XMP data may be there to begin with.

[DavidOfMA]

Thanks. I have read that part of the Help, but I'm so unfamiliar with XMP that I couldn't get a clear sense of what the best thing to do would be. At the moment, my use of metadata outside IMatch is almost nonexistent. Perhaps I'm best off sticking with the IMatch defaults until I have reason to do otherwise.

[Mario]

Perhaps I'm best off sticking with the IMatch defaults until I have reason to do otherwise.

That's a good idea. The defaults have been chosen to work with the standard applications used for working with digital images, in typical RAW processor or Adobe workflows and to be compliant with the Metadata Working Group recommendations.

JPEG, DNG, TIFF, PSD, DNG and some other formats must have embedded XMP data, else it will not be found/used/updated by many other applications.

[DavidOfMA]

Thanks. I'll turn metadata updating on and let it happen according to the defaults.