Google VisualRank for Image Search

Google researchers are claiming that a newly developed approach to visual search may do for image searching what PageRank did for text search. "The research paper, 'PageRank for Product Image Search,' is focused on a subset of the images that the giant search engine has cataloged because of the tremendous computing costs required to analyze and compare digital images. To do this for all of the images indexed by the search engine would be impractical, the researchers said. Google does not disclose how many images it has cataloged, but it asserts that its Google Image Search is the 'most comprehensive image search on the Web.'"