1. A method of determining a geometric parameter of a region from an image, wherein the image is collected to develop a navigation database, the method comprising: determining calibration values corresponding to a camera mounted on a vehicle; capturing a plurality of images of geographic features, the plurality of images captured by the camera mounted on the vehicle; identifying a single image from the plurality of images; and determining a geometric parameter of a region in the single image based on the determined calibration values and no images other than the single image, the geometric parameter being a real-world distance.