A webmaster is upset that his images aren't being indexed from his site. He posted a complaint in the Google Webmaster Help forums, in which we learn two things:
(1) This webmaster was blocking Google from indexing those images with robots.txt file. This actually happens way too often.
So if you want your images indexed, first make sure you allow Google to index them and then make sure the crawlers can process the links to them.
Forum discussion at Google Webmaster Help.