There are a couple of unexpected differences in the output file (I'm diffing the output of "exiftool -a -G1 -s" to see what changed).
- The YCbCrPositioning tag has changed from "Co-Sited" in the JPG file to "Centered" in the MIE.
- The InteropIFD group isn't copied at all.
If I copy the MIE data back into the original JPG, YCbCrPositioning doesn't change (it stays correctly set to "Co-Sited"), but if I copy the MIE into a JPG with all the metadata stripped out, it does end up with YCbCrPositioning = "Centered".
I don't know if this is expected or not, or if it happens with any other tags, or if there's a more sensible way to back up all the metadata from an image.
This is all with exiftool 6.76 - apologies if this has changed in a later version, but I couldn't see anything relevant in the change log.
The files mentioned above are
here.
Cheers,
Scott