An image sensor includes a pixel with a photosensitive region accommodated within a semiconductor substrate and a MOS capacitive element with a conducting electrode electrically isolated by a dielectric layer. The dielectric layer forms an interface with both the photosensitive region and the semiconductor substrate, the interface of the dielectric layer including charge traps. A control circuit biases the electrode of the MOS capacitive element with a charge pumping signal designed to generate an alternation of successive inversion regimes and accumulation regimes in the photosensitive region. The charge pumping signal produces recombinations of photogenerated charges in the charge traps of the interface of the dielectric layer and the generation of a substrate current to empty recombined photogenerated charges.