Imaging theory for X-ray pixel detectors

In this paper we discuss the physical processes from the first interaction of an X-ray photon to the spatial distribution of charge carriers at the electrodes of a pixel detector. The implications of these processes on the achievable position and energy resolution have been investigated with simulation calculations and with measurements employing the Medipix detectors. As the next generation detectors will be capable of energy resolution we present two methods of energy exploitation in X-ray imaging, i.e. energy weighting and material reconstruction.