Automated metric calibration of colour digital cameras

Abstract Consumer‐grade digital cameras have become commonplace and with calibration there is significant potential for their use in photogrammetric applications. This paper describes a new method for automatic camera calibration, which is suited to colour digital cameras. Two innovations are central to the developed process. The first is exploitation of RGB colour attributes in the design of automatically detected and identified coded targets. The second is a new approach to initial value determination for relative orientation, which then supports fully automatic initial network exterior orientation and subsequent bundle adjustment with self‐calibration. Accuracy aspects are also touched upon and the impact of chromatic aberration is discussed. Finally, an example of the automatic calibration process, which is implemented in the iWitness system, is presented for the case of multiple zoom settings of a consumer‐grade digital camera.