We are storing images as files with names/paths, metadata, etc. in
PostGIS (as our images are often associated with a location, being
things like field specimen images, or seabed pictures we use PostGIS to
store & query the location info, and UMN Mapserver as the engine driving
a map based image selection tool - www.atlasmd.com)
Atlas originally used Firebird RDBMS for image data, but was migrated to
PostGIS to fully support OGC compliant spatial functionality.
The additional step we have implemented to ensure a two way link between
the images & the data is to write the db primary key to an EXIF field in
each image as it is uploaded. This means that given an image, we can
access it's data from the DB, (by looking up the key which is embedded
in the image) instead of the usual approach which only permits a link
the other way.
Cheers,
Brent Wood