An image sensor includes a plurality of self-resetting pixels including: a mechanism converting detected electromagnetic energy into a proportional electric current; an integrating capacitor including a mechanism for fast charging to a first electric level and for controlled discharging to a second electric level; a mechanism for comparing the controlled discharge; a loopback mechanism, allowing automatic repetition of fast charging and controlled discharging cycles and counting of number of cycles occurring during a determined integration time; a mechanism measuring a residual electric charge present in the integrating capacitor on completion of the integration period; and a calibration mechanism using the measurement mechanism to measure and compensate for operating and production dispersions specific to each pixel.