2018.02.08 18:45 "[Tiff] TIFFTAG_RICHTIFFIPTC : registered as TIFF_LONG but commonly stored as TIFF_UNDEFINED", by Aaron Boxer

2018.02.08 20:20 "Re: [Tiff] TIFFTAG_RICHTIFFIPTC : registered as TIFF_LONG but commonly stored as TIFF_UNDEFINED", by Bob Friesenhahn

Originally, there was one manufacturer that got it wrong, used LONG while the data is of mixed datatype, and therefore only makes sense as BYTE or UNDEFINED on the TIFF level. Adobe chose to duplicate that mistake, so as

If it helps any, IPTC officially deprecated and disowned this format perhaps 20 years ago. :-)

Bob
--
Bob Friesenhahn
bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/