BUG: adding or removing keywords does not work with HEIC

[benwar]

Adding or removing keywords via -keywords+=... or -keywords-=... does not seem to work with HEIC files.  Exiftool reports the files as unchanged.

It works for JPG files without a problem.

[StarGeek]

If you take a look at the Supported File Types table, you'll see that HEIC does not support IPCT IIM/Legacy. 

Use Subject instead.

[benwar]

For HEIC, keywords is in XMP. However, only setting works - adding or removing does not. The same applies to XMP files.

[StarGeek]

Keywords in XMP is XMP-pdf:Keywords. If you take a look at the table for XMP-pdf, you'll see that the tag is a simple string, not a list type tag.  So you can set it or remove it as you would other string tags such as Description, but you can't alter it with list type tag commands.

[benwar]

Understood.  Thanks for the quick replies!