High dynamic range photogrammetry for synchronous luminance and geometry measurement

Abstract

This study developed high dynamic range photogrammetry for synchronous acquisition of luminance of targets across a scene and their three dimensional coordinates XYZ in the field. The high dynamic range photogrammetry deploys a single digital camera. A Canon Rebel T2i fitted with four Sigma lenses was used and calibrated in a laboratory. Photogrammetric coordinates, transformation equations, two lens radial distortion models, a 3D angular measurement tripod head mounted on a portable platform, and a measurement protocol were developed. The high dynamic range photogrammetry was validated in a laboratory experiment. The average errors of 1.8– 6.2% for luminance mapping seven grey checkers and 12.9–24.3 mm for measuring their XYZ coordinates are deemed acceptable in practice. The high dynamic range photogrammetry would supplement light and geometry measurement and stimulate many applications.