Fractional-readout oversampled image sensor

A method of operation within an integrated-circuit image sensor having a pixel array, the method comprising:

• after a first exposure interval that constitutes a first fraction of a frame interval, reading out of the pixel array first signals representative of total photocharge integrated within respective pixels during the first exposure interval;
• after a second exposure interval that constitutes a second fraction of the frame interval, reading out of the pixel array second signals representative of photocharge integrated within the pixels in excess of a threshold level, including removing the photocharge in excess of the threshold level from the pixels and leaving residual photocharge within the pixels;
• and
• after a third exposure interval that constitutes a third fraction of the frame interval and transpires after the second exposure interval, reading out of the pixel array third signals representative of a combination of at least the residual photocharge and photocharge integrated within the pixels during the third exposure interval.