PhotoRDF and rdfpic
an application of RDF to holiday pictures
Bert Bos, W3C
EU Workshop Semantic Web technologies,
22-23 Nov 2000
Luxembourg
The program rdfpic
A program to help a person describe pictures
- shows picture and a form side by side
- remembers form entries in a pop-up menu
- allows to repeat form fields automatically
- can create as well as modify descriptions
Designed for describing a series of related photos
(e.g., a holiday trip)
rdfpic technical
rdfpic currently only supports JPEG
metadata is stored as RDF
- stores metadata in JPEG "comment" chunks
- reads/writes local files or URL (HTTP GET & PUT)
- form fields derived from RDF schema (config file)
- new schemas can be added on the fly
With HTTP, reads image + RDF, but writes
only RDF
The PhotoRDF format
PhotoRDF is built on top of RDF
3 schemas:
- Dublin Core: creator, date, coverage, etc.
- simple form: no sub-fields
- Technical: camera, film, etc.
- Content: keywords for the DC subject field
- "portrait", "landscape", "macro", etc.
Interpretation of Dublin Core fields
Dublin Core fields generic for all creations
Interpretation for photography:
- Creator = photographer
- Date = date + time picture taken
- Relation = occasion or title of series
- Coverage = place where picture was taken
Type is always "image"
Format is always "image/jpeg"
Role of Jigsaw server
Jigsaw server used to show integration with HTTP
- HTTP PUT to save pictures remotely
- HTTP content-negotiation:
- Same URL for image and metadata
- Header "Accept: image/jpeg" to get JPEG
- Header "Accept: text/rdf" to get RDF
- Image and metadata also have different URLs
Goals
For both rdfpic and PhotoRDF
- balance: useful metadata vs time to create it
- easy to use, no RDF knowledge req'd
- demo of W3C technologies:
But most of all:
- a way to scan & index our holiday pictures...
during work hours :-)
Conclusions & future work
- captures typical photo-album descriptions
- easy to create thumbnail pages automagically
- draws attention, gets reactions
Future:
- integration with (metadata stored by) digital cameras
- RDF search engine
- other picture formats (PNG, SVG?)
Links