Painting the Web

Mining Your Photos

In earlier chapters, we peeked beneath the hard surface of our photos. In this chapter, I want to cover mining your photos for information and then using that information effectively.

When you use most of the photo editors I covered in Chapter 3, you're given the option to edit metadata associated with each image. This metadata includes title, description, photographer, keywords, and a whole lot of other information. This is then added to the information that most cameras add to the photo, such as aperture, ISO, and other relevant data. Each photo becomes a miniature filesystem, with data that can be accessed, edited, and restored.

Figure 15-9. Generated bar graph, with the mouse cursor over the Technology category

Tip

If you're really interested in what you can store in a photo, check out Stepic, a Python tool that supports steganography: storing information in photos. Stepic is available at http://domnit.org/2007/02/stepic.

Most of the online photo sites, such as Flickr, can read this data and do something with it. For instance, the sites will pull out title, keywords, and description, and use this data to annotate the photo at the site so you don't have to. The keywords typically get built into tags for external search, and if present, they'll also list the EXIF camera information, which is really handy for people wondering about the camera settings for a photo.