An active pixel sensor comprises a photodiode providing a photodiode output current indicative of an intensity of light incident the photodiode and an integrator circuit electrically coupled to the photodiode. The integrator circuit is configured to provide a pixel voltage representing an integration of the photodiode output current when the photodiode is exposed to light and dark leakage current through the photodiode when the photodiode is not exposed to light. The integrator circuit is configured to set a reverse bias voltage on the photodiode and respond to at least one control input to set the reverse bias voltage to a first level. The active pixel sensor comprises a feedback loop configured to receive the pixel voltage and control the integrator circuit to adjust the reverse bias voltage to substantially reduce the dark leakage current through the photodiode to a desired level.