Carl Bialik from WSJ writes "Retrievr gives budding artists an impractical but addictive way to find photographs on Flickr: a search engine powered exclusively by mouse-made doodles. From the article: 'Retrievr, Mr. Langreiter says, "doesn't look at specific forms." Art history buffs might like to think of it as photo-search by way of Impressionism. The Retrievr engine dissects a photo like a gallery connoisseur who lost his bifocals: It focuses on regions of colors rather than specific shapes and lines. "It is, actually, a simple scheme," says Mr. Langreiter. Retrievr creates and stores a compact representation of each photo in its database. The system pulls only the most important features — broad shapes, blocks of color and spatial relationships between different colored areas — out of detailed images to create shorthand approximations of every photo. (The storage mechanism extracts the 120 "strongest" features from an image to create something called a "wavelet transform," which contains much less data than the photo itself and facilitates lightning-fast searches.)'"