Articles Tagged with "Metadata"

14/01/2008: GPS & Cameras

We are now starting to see the arrival of GPS chips in cameras. Why? Well, so that photos can be tagged with their latitude and longitude. Then when you upload your photos to a computer, they can be plonked onto a map — nifty little trick, and I’m sure people will come up with plenty of other neat ways of using this extra data.

But just wait until Galileo (the European Space Agency’s rival to US-based GPS) goes live. Galileo will provide far higher resolution co-ordinates, potentially narrowing your position down to within a few inches. Combine that with the gyroscopes already build into many higher end digital cameras, which are able to determine the orientation of the camera, and online geotagging — the practice of marking up information on the web with geographic co-ordinates — and you end up with a camera which doesn’t just take pictures, but knows which famous landmark you’ve decided to take a snap of!

09/01/2008: X-Blog-Name

OK, so the Trackback specification includes the ability for a pinging page to specify its article title and blog name when it sends a trackback ping. However, these fields are optional. When not present, typically the recipient of the ping will then make an HTTP request back to the pinger to determine the article title from the page’s <title> element. But there is no standardised way of determining the blog name — or more generically, because Trackback can be used by sites other than blogs — the name of the “collection of web pages”.

The following informal specification suggests a method of determining the name of the collection of documents to which a given HTML document belongs. It also provides a clear way for you to mark your own HTML documents as being part of a particular collection.

Determining the Collection for a Given Document

Attempt to find the name of the collection…

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!