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June 2010
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2010.06.12 15:52 "Re: libtiff and IPTC tag", by Lee Howard
Andreas, If you would please file this on Bugzilla that would help keep this issue on the to-do list. Attaching a proposed patch would help it get resolved sooner. Thanks, Lee. Andreas Kleinert wrote: > Hi all, > > I'm using libtiff 3.9.2. in SView5 (.NET version) - in > parallel, for some special cases, I've got some additional > custom TIFF parser included in the same codebase. > > I've encountered again a TIFF image where libtiff gives the > following error/warning (i.e. debug log output): > > <long filename>: wrong data type 7 for "RichTIFFIPTC"; tag ignored > > I would expect, that libtiff handles that case gracefully, > i.e. under > > http://www.awaresystems.be/imaging/tiff/tifftags/iptc.html > (greetings to Joris van Damme - whenever I google for some > tifftag, this is one of the first page hits... ;-) > > it is written for that tag > > Type UNDEFINED or BYTE > > and there even is a statement included > > Often times, the datatype is incorrectly specified as LONG. > > A required tag type fix from BYTE (1) to UNDEFINED (7) should > not be a reason to reject this tag, IMHO (I have some doubts > regarding interchangeability with LONG, but that is type 4, > and as long as we just read bytes, there won't occur any > endianess isssue for sure). > > However in tif_dirinfo.c within TIFFFieldInfo it is defined that > libtiff expects LONG for TIFFTAG_RICHTIFFIPTC (custom field)... > > Other descriptions of this issue (via Google): > http://www.imagemagick.org/discourse-server/viewtopic.php?f=1&t=12872 > http://www.google.com/support/forum/p/Picasa/thread?tid=43cace71df6d6150&hl=en > http://forums.cgsociety.org/archive/index.php/t-769395.html > > There also were some statements found, that the original RichTIFF spec > defined it as BYTE. > > *** > > For now I'll add a workaround using my internal parser. > > For the future it would be good to either have libtiff being > more error tolerant, or having some kind of "strict" vs. > "sloppy" parsing (maybe there is such switch yet, and I > overlooked it). > > *** > > Sample image can be provided by email if needed. > > Best Regards, > Andreas > > >