1. A method for processing digital image data taken from a three-dimensional topographic area including terrain and a right of way including a first and a second object to establish a clearance surface to define clearance violations within a boundary area, the method comprising: locating waypoints to define a centerline and the boundary area to be analyzed; determining vegetation coordinate points in the scene from the digital image data; determining ground coordinate points from the digital image data; constructing a clearance surface segment within the boundary area between the first and second object, the clearance surface segment determined from the location of the first and second object and clearance criteria; using the clearance surface segment to define a violation region.