1. A method for detecting pedestrians in images, comprising: identifying, by a computing system comprising one or more electronic devices, a pedestrian within an image obtained from a camera positioned relative to a vehicle; determining, by the computing system, an estimated support location for the pedestrian within the image; determining, by the computing system, a supplemental portion of data correlated with the pedestrian, the supplemental portion of data obtained from a sensor other than the camera; determining, by the computing system, an estimated location of the pedestrian within three-dimensional space based at least in part on (i) the estimated support location for the pedestrian within the image, (ii) a known relative location of the camera to the vehicle, and (iii) the supplemental portion of data; obtaining, by the computing system, map data descriptive of a geographic area surrounding the vehicle, the map data including relative locations of ground surfaces proximate to the vehicle; determining, by the computing system, a revised estimated location of a pedestrian within three-dimensional space based at least in part on the estimated location and the map data; and providing, by the computing system, at least a portion of the image corresponding to the pedestrian and the estimated location of the pedestrian within the three-dimensional space to an object classification application.