A Review of Computer-Assisted Photo Interpretation Research at USAETL (U.S. Army Engineer Topographic Laboratories)

A program in computer-assisted photo interpretation research (CAPIR) was initiated at the U.S. Army Engineer Topographic Laboratories (USAETL) in 1979. The primary objective was to develop and implement concepts to increase the productivity of the human photo interpreter tasked with extracting terrain data from aerial imagery. Early efforts focused on implementation of interactive software for direct capture of digital map data from stereo mapping and reconnaissance photography. The development of a hardcopy stereo workstation with integral computer graphic superposition has been essential to provide a suitable interactive, closed-loop environment for the photo interpreter. This paper provides a brief introduction to the problem domain of terrain analysis and outlines the evolution of the CAPIR program emphasizing the special requirements for an effective man-machine interface. The application of current CAPIR technology to typical terrain data capture problems is discussed with selected examples of technology transfer and examples of new commercial photogrammetric instrumentation incorporating graphic superposition capabilities. Opportunities to extend CAPIR concepts to softcopy terrain analysis based on adaptation of digital image processing technology are then presented. Digital image image source materials and potential softcopy processing advantages are discussed and key requirements for effective softcopy terrain analysis are summarized.