Patent ID: 8767098

Claim:
An image sensor for generating image data, the image sensor comprising: a pixel array including a plurality of pixel cells arranged into rows and columns for generating analog image data; a bit line coupled to at least one of the pixels within a column of the pixel array; and readout circuitry coupled to the bit line to readout the analog image data during a sampling time, the readout circuitry including: preprocessing logic coupled to the bit line for preprocessing the analog image data to reduce noise, wherein the preprocessing of the analog image data includes, generating multiple samples of the analog image data during the sampling time; limiting values of the multiple samples by: replacing the multiple samples that have a value that exceeds a programmable upper threshold with the programmable upper threshold, and replacing the multiple samples that have a value that is less than a programmable lower threshold with the programmable lower threshold; pre-conditioning the multiple samples by applying a weighting factor to each of the multiple samples in response to when a respective sample was generated during the sampling time; and determining and outputting a median value of the multiple samples, wherein the sampling time is a signal level sampling time of a correlated double sampling (CDS) period, and wherein the readout circuitry is configured to readout analog image data during the signal level sampling time and during a reset level sampling time of the CDS period, wherein the preprocessing of the analog image data includes preprocessing a reset level and preprocessing a signal level.