An on-chip hot pixel identification and correction approach in CMOS imagers

The appearance of hot pixels significantly degrades the image qualities over the image sensor lifetime. In this paper, a robust readout circuitry is proposed to on-chip detect and mask the hot pixels in image sensors. Conventionally, hot pixels modeled as salt and pepper noise are corrected by an low pass filter which is applied to the entire image. However, this results the loss of overall image sharpness. The proposed approach provides the exact hot pixel positions before correction. It does not require extra non-volatile memory to store the map of the hot pixels. In addition, this method allows identification of new hot pixels generated during the sensor lifetime.