Abstract: A method for reading a pixel, the method includes: (i) generating a first signal responsive to light sensed by the pixel during a first exposure period; (ii) comparing a first threshold to a first value of the first signal; (iii) writing a second value to the pixel; wherein the second value equals the first threshold if the first value exceeds the first threshold; wherein the second value equals the first value is the first signal is below the first threshold; (iv) generating a third signal responsive to the second value and to light sensed by the pixel during a second exposure period; (v) reading the third signal; and (vi) calculating a digital detection signal in response to a value of the third signal and in response to a first threshold.