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!