Last winter I reviewed a Flickr search tool called Retrievr. It allows you to make a drawing and then finds Flickr photos based on what you drew. I found it worked best when using large swathes of color.
Now there’s a company called xcavator that searches Flickr based on specified points within a photograph you choose. The demo is available at http://www.xcavator.net and is integrated with Flickr; the search sets (photographs) are predefined and very limited at the moment.
When you first go to the site you’ll be asked to review either a little movie that explains how xcavator works or see an HTML overview. The movie’s okay; it walks you through the process of finding an interesting picture from the predefined sets (there are only a few of them and this is annoying), then clicking on “points” around the picture to delineate what’s important about the picture. As you click on points the picture sets refresh, narrowing down to show only those pictures which are similar to the pictures and points you’ve picked.
I tried it, opening up the flowers photoset, picking a rose, and then clicking on various parts of the rose. xcavator matched the color, but I couldn’t get the photomatch to work as well for finding actual roses. In experimenting I discovered that I did better when I started with a photo of a single flower (as opposed to lots of flowers) and when I clicked on multiple points — half a dozen or so — instead of just a few. As you find photos you like you can click and drag them into a “Faves” strip at the bottom of the screen; double-clicking on a photo there will take you to its Flickr page.
If you enjoyed Retrievr at all try this tool. The fact that what it searches is so limited is frustrating, but you should be able to find at least one pre-defined set of photographs that’s worth experimenting with.