Automated, Targetless Photogrammetric Measurement: Potential and Limitations

Abstract

Close-range photogrammetry is now a widely adopted tool for a host of 3D measurement tasks across areas as diverse as industrial metrology, forensics, and heritage recording. Whereas with industrial and engineering applications the utilization of targets is nearly universal, the adoption of newly developed automated, targetless orientation and object reconstruction is becoming more widespread in other application domains. This naturally poses the question of why so-called structure-from-motion (SFM) or feature-based matching (FBM) techniques for automatic photogrammetric measurement have yet to be employed to any significant extent in large-scale metrology, despite the obviously appealing prospect of dispensing with artificial signalization, be it through physical targets or projection schemes. This article begins by reviewing the development of targetless, automated photogrammetric measurement, which has been given extra impetus through the introduction of drones as camera platforms.