FourEyes is an interactive, power-assisted tool for segmenting and annotating images. Click on some regions, give them a label, and FourEyes extrapolates the label to other regions on the image and in the database. This could be implemented by choosing a single image feature like color or texture and forming, say, a Gaussian model of the label in that feature space. However, that naively assumes that one model will be suitable for all kinds of labels in all kinds of imagery. Instead, FourEyes has a "society of models" among which it selects and combines models to produce a labeling. This selection process is guided solely by the examples given by the user.
The figure above is an example of FourEyes extrapolating the labels "building," "car," and "street" from a few examples of each (highlighted in red). Click for a full screen shot. Also check out a country-scene example and the new Photobook-6 interface.