US Patent 7388609 Dynamic identification and correction of defective pixels

Rather than storing a table within a digital camera or other optical device of defective pixels within its image sensor, defective pixels are dynamically identified by comparing the output values of individual pixels under test with those of neighboring pixels. If the neighbors are all above or below the pixel under test by a defined threshold amount, the output of the pixel under test is replaced with a value calculated from the outputs of neighboring pixels.