An image sensor includes a plurality of pixels, a plurality of sense circuits, and a count circuit. Each sense circuit is configured to read out electrical signals from at least one pixel associated with the sense circuit in order to generate data representing whether or not photons have been received by the sense circuit. The count circuit is in communication with a sense circuit selected from the plurality of sense circuits. The count circuit is configured to provide integration results for the pixels associated with the sense circuits based on the data received from the sense circuits.