MODELLING OF CHROMATIC ABERRATION FOR HIGH PRECISION PHOTOGRAMMETRY

Abstract

Chromatic aberration appears for almost all lenses for imaging based on white light. The effect degrades image quality for both b/w and colour cameras. This paper discusses the possibilities of modelling chromatic aberration with self-calibrating bundle adjustment for high-precision photogrammetric 3D point measurement using all three channels of a true colour image. After a survey on common types of digital colour sensors, wave-length dependent imaging errors of usual lenses are discussed. Consequently, different options for the correction of the occurring effects are derived. The resulting effect on image and object accuracy is verified by various test field calibrations using different combinations of digital colour cameras and lenses. For standard imaging configurations in close-range photogrammetry, a significant enhancement of inner precision by a factor of 1.7 can be proven. It can be shown that the length measurement error for standardized imaging configurations can be improved slightly whereby final results are still on investigation.