How to write Title/Description data to the different metadata types?

[Spike817]

The metadata editing page in the wiki indicates that Aves can create and/or modify Title/Description metadata in Exif, IPTC, and XMP for JPEGs.

By default, when I edit a photo's Title/Description it looks like it is stored only in the XMP metadata. That is fine and I can see this data in Windows File Explorer and Exiftool. However, I'm currently doing some GIS stuff in QGIS and while Exif data is very easily read... XMP data is not.

So, what I'm wondering is... How do I get my Title/Description edits in Aves to write to the respective Exif tags instead of the XMP ones?
Or more optimally, how can I go about writing Title/Description data to both Exif and XMP?

[deckerst]

Related code here:

aves/lib/model/entry/extensions/metadata_edition.dart

Line 228 in a9f88cb

Future<Set<EntryDataType>> editTitleDescription(Map<DescriptionField, String?> fields) async {

  // write title:
  // - IPTC / object-name, if IPTC exists
  // - XMP / dc:title
  // write description:
  // - Exif / ImageDescription
  // - IPTC / caption-abstract, if IPTC exists
  // - XMP / dc:description

For description at least it should already be written to both Exif and XMP.
In which Exif field specifically would you store the title?

[deckerst]

By the way, if you know what you're looking for, you can also use the Info page search in Aves, which is sometimes useful for items with many/messy fields.

[Spike817]

If I use the "Edit title & description" tag in Aves and give a jpeg a description... Should it not appear in the Exif IFD0 tab tagged as Image Description just as it is in your screenshot there?

[deckerst]

Right, it should. But I've just tried it in practice, and only the XMP field was written, not the Exif one, so it seems there's a bug.

[deckerst]

After digging, I see that it's intended, not a bug.

In Aves v1.7.9, I changed it so:
editing description writes XMP dc:description, and clears Exif ImageDescription/UserComment``

Rationale here. Basically, the Exif field is problematic with non-ASCII content, so it's best not to use it.

[Spike817]

Thanks deckerst! I sppreciate the work you do.

I see how that would be problematic for some of our non-english users.

Having an option to at least write to ImageDescription / UserComment if needed would be nice in my opinion. But XMP appears in Exiftool, Windows File Explorer, and Aves easily enough — so it's nothing necessary.