Metadata of the XMP sidecar is written incorrectly


I have the following setup:
all metadata is written (to an XMP sidecar) using Photo Mechanic Plus.
Sometimes I work with Capture One (v 14.2), sometimes with Photolab 4.3.1 on a Windows 10 computer.
All exported Jpegs contain the correct metadata and are also displayed correctly by Photo Mechanic Plus.
All exported jpegs contain the correct metadata and are also displayed correctly by Photo Mechanic.
When uploading to an online image database (piwigo), the metadata of the Photolab-Jpegs are not read. With the C1 generatet Jepgs there is no problem. It seems to be due to special characters (like ä, ü or `). If I delete them, the metadata will be read, or if I overwrite all metadata again with Photo Mechanic.
Photolab seems to produce a format problem (unicode, mac roman etc.).
Does anyone have any further experience with this?
And maybe even a solution?

Thanks and greetings

I’ve tested this on my Mac with Lightroom, Capture One and PhotoLab 4.

They use different tags and tag groups as you can see in the screenshot.

  • C1 writes IPTC Keywords, XMP Subject and XMP Hierarchical Subject tags
  • Lr writes IPTC Keywords and XMP Subject tags (blue lines above)
  • PL writes XMP Subject and XMP Hierarchical Subject tags

All exported files show the keyword “Türen” correctly in Apple Preview.
My guess is, that piwigo reads IPTC only, therefore missing the keyword written by PhotoLab 4.

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It is always potentially problematic when managing metadata between applications. DXO needs to work on the mapping of PL4 metadata…


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Thanks for your testing.
Image programs, the Finder or Explorer display the IPTC metadata correctly. Only piwigo does not read the PL4 files anymore, they all remain empty. This seems to be a piwigo problem, but it is noticeable that PL4 seems to write the metadata, especially the special characters, in a different format than all other programs.



PL4 seems to have a problem writing the IPTC metadata on export.
The IPTC metadata was generated by Photo Mechanic Plus in an xmp sidecar file.
The metadata of the exported Jpeg looks ok at first sight, but they are no longer read by other programs. The problem seems to occur with special characters (ä, ö or `).
Has anyone had similar experiences?
Thanks and greetings

See here for possible answer

Other programs is a bit vague. I’ll try to be more explicit. PhotoLab 4 does export the headline and caption information (can be read by some applications) in jpegs but is not readable by WordPress when the photos are uploaded. Re-encoding the jpegs with Photo Mill X in my case does make the headline/title and caption/description readable by WordPress.

Whatever PhotoLab 4 is doing which makes its metadata less compatible on export, DxO should stop doing/fix right away. This is a serious inconvenience and cost me more than a half a day of my life to sort out. I resent that half-day lost to DxO carelessness and many other photographers may do the same. Leaving bugs like this in PhotoLab wastes accumulated customer goodwill pointlessly. Of course, I have quite a bit of goodwill to DxO but for them to squander that goodwill seems silly.

This thread seems to be a duplicate thread. Perhaps @sgospodarenko would be kind enough to merge it. @bildbaendiger, better not to create duplicate threads and they muddy the discussion.

Hello Alec,

you are right, that is my fault, sorry.
The first entry was not released for 2 days, so I thought it was lost. When I then wrote the 2nd, both have been unlocked at the same time. I was also more detailed in the first post. (i have the problems with PL4 metadata when uploading to piwigo).


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Done! :slight_smile:

Svetlana G.

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