Robust digitization and digital non-uniformity correction in a single-chip CMOS camera

Analog circuitry, digitization and subsequent digital non-uniformity correction in a single-chip digital CMOS camera are described. The sensor array of 720 × 576 active pixels is followed by a simple circuit implementing correlated double sampling, sample-and-hold function and A/D conversion with minimum analog hardware. The non-uniformity introduced by parameter variations in the analog circuitry is digitally corrected, resulting in measured rest non-uniformity and noise of 0.4% rms of the saturation signal. This level of non-uniformity leads to image quality comparable to the CCD.