1. A method for determining specularity, the method comprising: identifying, by the one or more computing devices, a set of images including a geographic area; for each particular image of the set determining, by the one or more computing devices, an intensity value for the geographic area for that particular image to generate a set of intensity values; identifying, by the one or more computing devices, a specularity function based on the set of intensity values; and classifying, by the one or more computing devices, specularity of the geographic area based on the specularity function.