The disclosure relates to a microelectronic image sensor device comprising: at least one detector formed by at least one photo-detector element, at least one integration capacitor associated to the photo-detector and capable of providing at least one analogue signal capable of varying at least according to a current provided by the detector, and analogue/digital conversion means for equalising charges comprising: a comparator, injector means capable of modifying the analogue signal by one or more injections, respectively of a given quantity of charge, into the capacitor, command means for charge injector means capable of modulating the given quantity of charge injected according to the intensity of said current.