XMP EXIF 2.21?

[blue-j]

I have a file (attached) that claims to be using EXIF 0221 (2.21) - but is XMP EXIF.  I don't believe XMP EXIF existed until 2.31, but I am prepared to be schooled.  I researched the heck out of this before coming to the forum.  Does anyone know the bottom line here?

- J

[Phil Harvey]

I have XMP specifications back to at least January 2004 which include the exif schema namespace.  This would be somewhere around the time of Exif 2.2.1 or so, but I don't see the problem with using this schema to represent Exif of any version.

- Phil

[blue-j]

Good to know!  Any EXIF metadata for XMP spec prior to 2012 is not easy to come by.  I see you point to the XMP spec itself though?  Will check!

- J

[Phil Harvey]

Yes.  The 'exif' schema was originally defined in the XMP specification.  The Exif-for-XMP specification added the 'exifEX' schema.

- Phil

[blue-j]

There is literally no resource known to me that gathers any sort of historical knowledge about metadata aside from your platform (especially your amply commented source code).  I wonder if this is just a measure of software competition, topic dryness, or what.  As a relative newcomer (am I?) trying to suss all this out, there is really no central repo out there better than ExifTool.  I say this after reading specs and dealing with these matters for, well, several years now!

- J