2006.08.25 18:43 "RE: [Tiff] IPTC tag", by Chris Cox

What I posted will always work if the file is written correctly (and does - we have zero failures for non-corrupt files). If you mistakenly byteswapped the IPTC tag - then Photoshop will not be able to read it, because the data is not written correctly. If Libtiff is byteswapping IPTC tags - then LibTIFF needs to fix that bug ASAP and stop writing corrupt files. Also, any software that tries to re-byteswap IPTC tags is incorrect and needs to be fixed (but I've never seen or heard of that).

Chris

-----Original Message-----
From: tiff-bounces@lists.maptools.org on behalf of Joris
Sent: Fri 8/25/2006 6:30 AM
To: Phil Harvey; tiff@lists.maptools.org
Subject: Re: [Tiff] IPTC tag

I have found at least one utility (Nikon Capture) that won't read IPTC information unless the format LONG, and as you mentioned this is the way it is written by Adobe. So I don't think any IPTC support would be very useful unless it reads and writes as LONG too.

I just don't buy that sort of reasoning anymore... In my other post, I think I've clearly shown that the scheme Chris Cox mentions is the reading strategy implemented in Photoshop, misses out on some files very likely otherwise suspected to contain valid IPTC data (all files written by LibTiff, with byte order different from machine byte order and IPTC data written as longs, plus all files with IPTC data written as longs by any library at all, and subsequently byte order reversed by tiff handling software (like simple page concat!) an oneven number of times, plus...).