Last week I gave a joint IAM seminar with Jon Hare, as part of the IAM 2006/2007 seminar series.
The seminar was officially called “Bridging the Semantic Gap in Multimedia Information Retrieval: Top-down and Bottom-up Approaches”, although we decided that what we really were talking about was “The Ups and Downs of Image Retrieval”.
It was basically a follow up on the paper we presented at the Mastering the Gap workshop at the European Semantic Web Conference last year.
We described the two basic approaches to image retrieval (semantic-based and content-based) and introduced the issue of the semantic gap in image retrieval, in particular by looking at the user requests to real picture libraries and archives. We then went to describe how semantic web techniques might be used to overcome some of the issues, although it’s challenging when dealing with real archive data. Finally, Jon showed his amazing semantic space technique, which allows users to search collections of unannotated images using text keywords.
The slides are available in PDF (5.7M) and because of the movies/demos we used in the presentation as a Quicktime interactive movie in two sizes: large (118M) and small (13M).
The seminar itself was recored and podcast on the IAM seminar feed, but I don’t think it’s visible outside of ECS. We’ll try to get it put somewhere sensible soon.
I’m a geek and it’s awesome! I’m going to the London Hack Day event next month, guess I need to find a come up with something nice to hack up…
There’s a load of stuff I’ve been thinking about and planning to tinker with, but I think it would be great to participate in something new and unique that I wouldn’t be just be able to do on my own.
I’m really looking forward to it now!
After working in the “semantic web meets cultural heritage” domain for a number of years, there are many useful resources and tools I’ve become familiar with. I thought it would be useful to share some of these - hopefully it will be helpful to someone out there!
### Ontologies
The CIDOC CRM is an extremely rich core ontology for describing cultural heritage documentation. I know a fair bit about it, having used it in the Sculpteur and eCHASE projects but it’s best to look at the official CIDOC CRM site for more details.
Whilst I don’t think the VRA Core model is as powerful as CIDOC CRM, it seems to be more accessible and easier to get to grips with. The W3C Multimedia Semantics Incubator Group describe how VRA Core can be used in cultural heritage documentation in their report on Image Annotation on the Semantic Web.
### SKOS: Simple Knowledge Organization System
SKOS provides an OWL ontology for modeling knowledge organisation systems such as controlled lists/vocabularies/thesauri. It provides the means to describe thesauri concepts and their relationships (e.g. labels, alternative labels, broader and narrower concepts, concept schemes and so on).
The best starting point is the SKOS Core Guide, that shows you how to go about modeling a thesaurus scheme in SKOS.
### Geonames
Geonames is a fantastic resource that provides information on locations in semantic web format (i.e. RDF). For example, check out Southampton in RDF! Their website has a nice Google Maps interface, but the really great thing is the Geonames web service that lets you match a query string (e.g. “Southampton, England”) to a specific place. I’ve used this service to add rich geographical information (e.g. latitude and longitude) to cultural archives that only had ambiguous text entries for place information.
### D2R Server
D2R Server provides a mapping mechanism to publish relational databases on the Semantic Web. The databases are exposed as RDF, and can be queried using SPARQL.
### Semantic Web Frameworks
There are loads of semantic web development frameworks, and there are a number of useful resources describing them too! Check out:
- Developers’ guide to semantic web toolkits by Chris Bizer
- Semantic Web Tools on the ESW Wiki.
Ones I’ve found particularly interesting are:
- ActiveRDF, which lets you build semantic web applications using Ruby on Rails.
- Semantic Media Wiki, which lets you define and extract machine processable (i.e. RDF) information within Wiki content. This is an extension to the popular MediaWiki system used by Wikipedia.
### Miscellaneous RDF Stuff
If you need to read/write RDF by hand, use N3 rather than RDF/XML - it’s a lot easier!
Also, if you need to write any code to generate RDF data, consider using NTriples. Each triple goes on a separate line, so you don’t need to worry about setting up the RDF/XML document structure correctly.