Semi-automated 3-D Building Extraction from Stereo Imagery

The production of geospatial information from overhead imagery is generally a labor-intensive process. Analysts must accurately delineate and extract important features, such as buildings, roads, and landcover from the imagery. Automated feature extraction (AFE) tools offer the prospect of reducing analyst´s workload. This paper presents a new tool, called iMVS, for extracting buildings and discusses user testing conducted by the National Geospatial-Intelligence Agency (NGA). Using a semi-automated approach, iMVS processes two or more images to form a set of hypothesized 3-D buildings. When the user clicks on one of the building vertices, the system determines which hypothesis is the best fit and extracts the building. A set of powerful editing tools support rapid clean-up of the extraction, including extraction of complex buildings. User testing of iMVS provides an assessment of the benefits and identifies areas for system improvement.