Automatic interior orientation of digital aerial images

A fully operational automatic interior orientation (AUTO-IO) for digital aerial images based on a modified Hough Transform for rough localization of fiducial marks and least-squares matching for precise measurement is introduced in this paper. For cameras with fiducial mark identification symbols, e.g., as used in Leica RC30 cameras, the program is capable of determining the orientation of the photos. Results are presented using images taken by Leica and Zeiss cameras, which were scanned on different scanners in various resolutions to demonstrate the potential and robustness of the automatic IO is implemented on a Helava/Leica DPW770 Digital Photogrammetric Workstation and is used in a digital production environment at swissair Photo+Surveys Ltd., Switzerland.