Photoshop Album is one of those rare applications that make meta tagging so easy that even "normal people" can use it. Now, let's say I want to create a taxonomy and share it with other users, is there a way to do it so that a) they don't need to re-create those tags, and b) they're going to use my controlled vocabulary in order to avoid alternate spellings and other discrepancies? I could even throw in some fun such as nice, well chosen thumbnails for all those tags. (Don't you love an app than lets you choose your own thumbnails to visualize metatags? And you should see the feature in action, it's very graceful.)

The goal is to keep everyone on the same page to feed a common database. Is there an explicit intersection between desktop photo management tools and the semantic web (say, an ontology created with Protégé)? Any leads are appreciated, and this question is not limited to Photoshop Album, so if this is possible with, say, iView MediaPro (which supports so-called "catalog sets") or ACDSee, I'm eager to hear about it (in the comments for everyone to enjoy), thanks.

I should point out that the Fotonotes/Fotowiki approach is interesting, and I love how Flickr lets you annotate pictures (though I didn't try it myself yet), but my idea is to structure things as much as possible, so the two approaches are in my opinion complimentary rather than swappable.

05/25/04 update: after more research, the problem with most desktop apps is that, though they do read EXIF data, they don't contribute additional tags to it but rather keep the metadata in their internal database. This is of course totally backwards from an interop perspective. What I want is something similar to ID3 tag editors in the digital music world, so that all the categorization work done on the desktop can be used in other tools and online as well. This review at Amazon is apparently good homework (again, Amazon.com, review permalinks please):

"The great weakness of ACDSee 6 is its disjointed metadata management capabilities. ACDSee uses two separately-maintained mechanisms for metadata management; a proprietary internal database that centrally stores image thumbnails, notes, keywords, category and ranking information; and the EXIF standard (used by most digital cameras) that embeds metadata information inside pictures themselves. [...]

The independence of ACDSee's internal database and EXIF support subsystems guarantees duplicative work effort for consumers who want to preserve their metadata in both subsystems. ACDSee does not make this easy. The program does not allow metadata to be transferred between the subsystems, so information must be entered twice. While the program supports batch operations (such as assigning the same Image Description to multiple photographs, e.g. Grandpa's Birthday) for ACDSee's internal database, batch operations are not supported for EXIF metadata. EXIF metadata entries must be painstakingly made on a per picture basis in ACDSee. Fortunately, ACDSee users can turn to freeware programs like Exifer, an EXIF and IPTC metadata editor, to make up for shortcomings in ACDSee's EXIF metadata capabilities.

It is too bad that ACDSee does not support IPTC metadata. Photo-sharing sites such as Fotki.com use IPTC Object Name (e.g., Office Christmas Party 2003) and Caption (e.g, Brian, his wife Maya, his workplace mistress Ciara) entries automatically. At these services, users of ACDSee end up potentially triplicating data entry - in ACDSee's internal database, in EXIF metadata, and then on the Internet.

Still, most of ACDSee's competitors do worse at supporting metadata standards. Microsoft Digital Image Library 9.0.603 imports the EXIF Image Description field as the program's Caption field, but all subsequent changes to captions are kept inside Digital Image Library's internal database only, and not exported back to the picture itself. Similarly, Adobe's PhotoShop Album 2 transparently supports the use of the EXIF Image Description field as the program's Caption field, but all notes are kept inside PhotoShop Album's internal catalog only. Jasc's Paint Shop Photo Album 4.03 can recognize EXIF metadata, the program does not make use of it. Users must instead rely on the Paint Shop Photo Album's internal database, which like its competitors, may be subject to breakage if a filename is changed outside the program. Photodex's CompuPic Pro 6.22 can only read (but not edit) EXIF metadata, and does not have internal notes or keywords facilities."

06/02/04 update: Brilliant Labs:

"One of BrilliantPhoto's main strengths is that is stores all of the descriptive information you enter for your photos (caption, keywords, etc.) in the meta-data of the actual photo file. I use the Information Interchange Model (IIM 4.1) standard from the IPTC to store this information so that it can be accessed by other programs."

06/03/04 update: this is very handy: Annotation Metadata in Digital Image Files (pdf).

07/14/04 update: Picasa (just acquired by Google) will save EXIF tags to the files themselves in its forthcoming 2.0 release.

08/23/04 update: Folksonomy: social classification, I am sharing this with you, The Cognitive Cost of Classification.

10/20/04 update: Peter Merholz: Metadata for the Masses.

12/30/04 update: Adam Mathes: Folksonomies - Cooperative Classification and Communication Through Shared Metadata.

01/09/05 update: Ian Irving: Folksonomies on Slashdot: revised, restated and summarized.

01/15/05 update (clearly drifting from photos to a broader stream about easy distributed categorization or whatever tags are about): Technorati tags, taggregator.

29/01/05 update: Cheap Eats at the Semantic Web Café.

02/09/05 update: Stewart Butterfield on Flickr.

9/19/05 update: Ian Davis on why tagging Is expensive.

06/28/06 update: now that I'm looking into this again for a simpler, lighter project, I find that BrilliantPhoto is gone (was on the block on eBay for a while).

09/23/07 update: free programs to write EXIF tags into pictures include IrfanView (with a plugin) and Itag while Imatch looks like a solid and inexpensive solution for more sophisticated needs such as batch editing.