2007.02.05 12:04 "Re: [Tiff] tag for tags", by Toby Thain

On 4-Feb-07, at 6:58 PM, Chris Cox wrote:

Huh?

The IPTC tags and XMP tags are separate from the Photoshop info.

I was assuming that the right way to do this (going from memory here, haven't referred to docs) would be to use the TIFF tag defined for PS IRBs to store the wrapped IPTC?

Both are stored exactly as their public specifications say they should be.

The Photoshop info can hold a second copy of the IPTC data, depending on how it was edited previously (to resolve conflicts).

So that's why I saw a nexus between the IPTC and File Info keywords?

Photoshop will also attempt to read and preserve EXIF metadata tags ("maker note" tags cannot be preserved, and many EXIF tags have to be updated).

Yes, there are multiple metadata standards, but I don't see why you think it's hidden.

Attempted humour :)

--T

Yes, the multiple standards can make things confusing, especially when there are conflicts between different data blocks.

But if you're writing the file, you can pick one (prefereably something simple, flexible and extensible like XMP) and stick with it.

PS. (yes, I'm actually advocating an XML standard - you can stop laughing now)

-----Original Message-----

From: tiff-bounces@lists.maptools.org on behalf of Toby Thain

On 4-Feb-07, at 6:15 PM, Alessandro Zummo wrote:

On Sun, 4 Feb 2007 18:07:20 -0200

is there any standard tag to hold tags (keywords) that have been used to describe an image?

Interoperability with PS' File Info interface might be the de facto standard. Photoshop stores them in a puzzle wrapped in an enigma and an IPTC stuffed in an IRB and legitimised by an Adobe specific

>>> tag so

on... you can find more details in Adobe's docs.

 sounds nice :)

 maybe we can define and register a tag?

Well it won't be interoperable with anything else. There are 1,001 metadata editors already out there, some more research might be worthwhile.

Chris Cox might chime in with Best-Practices-du-jour for Hiding Keywords in TIFF. :)