Articles Tagged with “Rdf”

16/07/2008: Extending hCard with RDFa

hCard is an HTML-based format for describing contacts (people, organisations, etc) on web pages. It allows you to mark up which elements represent their name, their address, their birthday and so forth.

While hCard offers many useful properties that can be used to describe contacts, some are considered beyond the scope of the hCard specification. This is where RDFa comes in…

09/03/2008: The Semantic Web

One of my current interests is the semantic web — that is, the push to move from publishing text on the Web to publishing structured data, which can actually be understood by computers (in so far as a computer can truly “understand” anything). By publishing information so that computers can understand it, you make the Web into a huge mine of interconnected data, free to be queried by everyone.

As an example of what I mean, searching for the keyword “train” on Google brings up results related to:

• trains, as a form of transport
• the band Train
• IT training courses
• toy trains

In the semantic web, the search engine and my computer would inherently understand the difference between these concepts, so if I wanted to know about the new Train album, I wouldn’t get any result related to locomotives!

What I’m particularly interested in is ways of embedding semantic data in ordinary web pages, so that we have a single web that can be…

10/05/2007: EXIF is Cool

If you’re not aware of EXIF, here’s what it is:

EXIF stands for Exchangeable Image File Format, and is a standard for storing interchange information in image files, especially those using JPEG compression. Most digital cameras now use the EXIF format.

That is, many images, including most of the JPEGs you get off modern digital cameras include a huge barrage of interesting information about the picture, such as:

• the date and time the photo was taken;
• the longitude and latitude where it was taken;
• whether or not the flash was fired; and
• what model of camera was used.

Pretty nifty, eh? But how to get all this information out? Well, PHP offers some fairly good EXIF functions. I rather like Masahide Kanzaki’s EXIF2RDF tool and am happy to announce that version 0.2.0 of demiblog will include a version of this for its photoblogging functionality. demiblog is very focused on providing good metadata, and EXIF2RDF will help the photoblogging parts to keep their end of the bargain!