We extend photometric stereo to make it work with internet
images, which are typically associated with different
viewpoints and significant noise. For popular tourism
sites, thousands of images can be obtained from internet
search engines. With these images, our method computes
the global illumination for each image and the surface orientation
at some scene points. The illumination information
can then be used to estimate the weather conditions (such
as sunny or cloudy) for each image, since there is a strong
correlation between weather and scene illumination. We
demonstrate our method on several challenging examples.