Write IPTC data to jpeg files - iptcembed()

[Markus Bulmer]

Hi,
I'm trying to do a photo album with php. The admins should be able to
write comments, descriptions etc. into the jpeg files via a web form. I
tried to implement this with the (still undocumented) function
iptcembed() and I didn't get it working properly. After hours of
debugging I found the following note in php.notes:

"This function [iptcembed()] currently only works for images that have
IPTC data embedded in them already."

Ok, that's exactly what I've found out myself so far but now my
assumption seems proofed.

Does anybody know a different way to write IPTC-data to jpeg-files that
do not aready have IPTC fields included? I haven't found anything in
Google yet... Any piece of source code may be helpful.

Thanks in advance,
Markus

PS.: There is an example at http://at.php.net/iptcembed that's exactly
where I started from. As mentioned before, this also works only if an
image already contains parsable IPTC data.

PPS.: Someone may wonder why I'm not using the EXIF fields - That's
quite simple, most EXIF fields are, according to spec, not to be
changed. IPTC can easily be imported into databases etc. etc.