An photon (energy) identifying radiation imaging device, for imaging x-ray, gamma ray and charged radiation in medical, dental and industrial applications. The imaging device includes a detector substrate and a readout substrate. The detector substrate has a plurality of detector pixels and the readout substrate has a plurality of corresponding pixel readout circuits. Each pixel readout circuit has circuitry for processing an input analog signal and also has one or more buffers for temporarily storing values corresponding to the signal of at least two individual incoming radiation events. The readout substrate includes a digital controller having digital processing units for carrying out off-pixel digital signal processing and data/rate reduction prior to readout.
