Yesterday Google announced in the Webmaster Central blog the added expansion for images within XML Sitemaps.

By expanding your XML Sitemap to include images in the new format, this will allow Google to easily learn which images you consider important. With image related queries being performed at Google every day, this extra step may help you to benefit from a bit of increased image related traffic.

For images that are accessible only via JavaScript or other difficult to spider methods, expanding on your XML Sitemap may help to ensure that Google can properly index them.

The following is a snippet of code, with an example of an image inclusion:

Code for Images in Google XML Sitemap

More information on adding images to your XML sitemap can be found at Webmaster Tools Help.

Also be sure to check out “Optimizing for Google Images” for more information on how to get your images ranked well by Google.