figure 2. Automatically generated annotated map of europe.
figure 3. 3D model of a scene (right) generated from photographs (left).
figure 4. Metadata for a photo downloaded from flickr.
types of information such as 3D structures or representative views. This observation suggests interesting parallels
between image collections and other
domains where link structure appears,
such as between people in social networks or between pages in the World
Figure 6 presents an example of a visual connectivity network for a set of images of Trafalgar Square. We compute
a measure of visual similarity between
every pair of images and connect those
above a threshold. Many photos are
not connected at all; they generally are
images of people or objects and not of
the square itself. A clustering algorithm
finds tightly connected components
of the network. This produces three
groups of images, each corresponding
to a different frequently photographed
scene from the square (marked by a
dotted blue line in the figure).
Mapping the World
In addition to the images themselves,
modern photo-sharing sites such as
Flickr collect a rich assortment of nonvisual information about photos. Many