Operational Procedure for Automatic True Orthophoto Generation

Orthophoto imagery is a valuable layer in a GIS because it provides a generic, inexpensive, and accurate base map. However, in cities with tall buildings it is difficult to create a seamless database of orthophoto imagery. Traditional methods for orthophoto rectification disregard buildings. In this paper, we describe a fully automated process, developed by ASI, that creates true orthophotography,” i.e. seamless imagery without building lean. In particular, we present a new mosaicking method, which automatically chooses the “best” imagery. We also present an automatic method for optimal seaming, which reduces the visibility of the seam line. Examples from Lower Manhattan, New York City, are presented.