trying to determine if a file can accept a keyword

[ChrisA]

using win10: VBA

I have three files to which I would like to add some keywords. I'm trying to identify in advance whether these can be added or not.

In two of them in the file explorer, right clicking on the file, selecting properties and going to the details tab there is a description section where the keywords can be manually added. The third file does not have such a section so so far as I can see, I will not be able to add keywords to this file.

Of the first two files, one already has some keywords and the keywords property is only listed when it is populated.

So I thought perhaps there is property which indicates that things like keywords can be populated.

I've taken a look at all the properties that Exif outputs and there is one common property that looks relevant - [ExifIFD] SubjectArea   - in the first two files. both have the value 2015 1511 2217 1330. The third file does not have this property. The file that does not have a description section does not have this property

Is this a reliable way of determining if a keyword can be added - rule would be something like 'if subjectarea exists then OK to add keywords.

Or is there a better way?

I'm just experimenting with attempting to add a temporary keyword, then read back - if result matches, then OK to add keywords, but this seems a bit heavy handed

[StarGeek]

SubjectArea is a region definition, normally used to mark faces. The first two numbers indicate the center point of the region and the second two numbers specify the width and height of the area surrounding that center point.

See the Windows Metadata post for a list of what tags Windows reads to fill the Properties window.

As you can see, there are multiple tag locations that Windows will read to fill its various properties, and it is entirely dependent upon the file type. And in some files, even if it exists, Windows may not read it. PNG files are an example of this, though this has supposedly changed with a recent update to Windows 11 (but not 10).

Additionally, the locations for keywords are unlikely to exist directly from a camera. It's something that will almost always be added during post-processing. So it's not something you would be able to check and see if it exists before adding.

IMO, the best place to add keywords is XMP:Subject. This can be added to most common file types, including JPEG, PNG, GIF, WebP, RAW camera images, AVIF, HEIC, and MP4/MOV. But not all programs will necessarily read it. Once it is in the file, it can always be copied to different tags with exiftool if you figure out a better location.