2003.11.17 00:45 "[Tiff] TIFF, v3.6.0. Fetching "custom" tags", by Chris Losinger

2003.11.17 14:23 "[Tiff] TIFF, v3.6.0. Fetching "custom" tags", by Frank Warmerdam

i'm trying to read data in tag 34665 (EXIF data). In 3.5.7, i used the tags/xtiff extension to read this non-core tag, and it worked fine.

But, since the v3.6.0.html page states:

"Custom tags can be set and fetched normally using TIFFSetField() and TIFFGetField(), and appear pretty much like normal tags to application code. "

I assume I can get rid of the tags/xtiff stuff and LibTiff will happily read and store any tags that it finds, even non-core tags, like 34665.

But, it doesn't seem to be working. When reading the TIFF dir, i get warnings about "unknown field with tag 34665 (0x8769) encountered", and when i call TIFFGetField, nothing is returned. It looks like v3.6.0. is behaving pretty much exactly like 3.5.7: complain about strange tags, then ignore them. But that's not what the documentation says is supposed to happen.



Could you provide a pointer to a file with this tag I could experiment with?


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