  A multi-imaging strategy is proposed and experimentally tested to improve the
accuracy of photon counting with an electron multiplying charge-coupled device
(EMCCD), by taking into account the random nature of its on-chip gain and the
possibility of multiple photo-detection events on one pixel. This strategy is
based on Bayesian estimation on each image, with a priori information given by
the sum of the images. The method works even for images with large dynamic
range, with more improvement in the low light level areas. In these areas, two
thirds of the variance added by the EMCCD in a conventional imaging mode are
removed, making the physical photon noise predominant in the detected image.

Astrophysics