1. A reporting pixel structure comprising: an image sensor; means for measuring a response of the image sensor to a received electromagnetic radiation; means for providing a report of a state of the image sensor output relative to a trigger level to an exposure controller; and means, responsive to an input signal from the exposure controller, for terminating exposure of the image sensor to the received electromagnetic radiation, wherein the received input signal is generated by the exposure controller in response to a plurality of reports received from a plurality of reporting pixel structures.