How does one rank in the Google Image Search Engine? A Cre8asite Forums member asks this question and a bunch of good advice is dispensed.
For one, filename, alt text, and surrounding text is important.
EGOL says that while on-page elements are important, rankings are also driven by searcher interest in the image. The more times it's accessed for a particular search phrase, the more likely it is relevant for the search.
The Google Webmaster Central blog shares some useful tips: don't put the bulk of your text in images, take advantage of ALT tags (but don't overload it), and look at the image-to-text ratio on your page.
Other resources: Search Engine Placement using Google Image Search and Optimizing Images for Search Engines.
Forum discussion continues at Cre8asite Forums.
This post was composed on September 24 and has been scheduled for publication on September 27.