As previously reported in [1], the NCP retina is a programmable smart sensor, in which images can be thresholded or haiftoned, and then processed in binary form by a micrc>-grained array processor. It is shown here that the observation of the current drawn by the NCP retina on its power supply can provide valuable global information on the observed scene. More generally, it yields an appealing solution to the generic output problem affecting artificial retinas Keywords: smart sensor, artificial retina, mixed analog digital, robot vision structure is shortly reviewed in section II. The NCP retina can process images to recognize shapes and track targets.