That seems to work in the same way as copying from the TIFF to the JP2. Surprising that I didn't think of trying this :) Apparently either there are too many choices or the one I was using was not correct for what I was trying to achieve.
It seems that exiftool is more powerful than I gave it credit for.
On Mar 23, 2011, at 11:39 AM, Dave Rice wrote:
> exiftool -tagsfromfile xmp.xml test.jp2
> instead of
> exiftool '-xmp<=xmp.xml' test.jp2
> Dave Rice