1. A method of determining camera parameters and three dimensional locations of features from a plurality of images of a geographic area, comprising: detecting features in the plurality of images, wherein each of the images cover at least a portion of the geographic area; comparing the detected features between respective ones of the images to determine a plurality of matched features; selecting a subset of the plurality of matched features, respective matched features selected depending on a quantity of other matched features in proximity to the respective matched features; and determining the camera parameters and the three dimensional positions of one or more of the matched features using the selected subset.