PHOTOGRAMMETRY USING CONVENTIONAL DIGITAL CAMERAS AND FREE SOFTWARE

Abstract

The main purpose of the article is to show a working methodology based on free software to obtain orthophotos with conventional digital cameras and make photogrammetric methods available to any person interested in obtaining good accuracy metric data from photographs. Architectural photographers will also find a correct way to make perspective corrections to their photographs. Considerations about shooting conditions are explained concerning focal length, aperture, focus and hyperfocal distance concept. Optical aberrations are analized, also basics of camera calibration and image correction process using free software are exposed. Software download links are provided. The article concludes with several examples applying the methodology described and showing details about obtained accuracy.

Keywords

• fotogrametría
• calibración
• restitución
• corrección perspectiva