DEFECT CORRECTION IN SOLID STATE IMAGING

The base bandwidth of any optical image that falls upon an imager is customized so that its uppermost spatial frequency is less than half the sampling frequency associated with the imager, thereby creating a power-vacant frequency window in the signal output of the imager. Since the edges of dead and hot pixels correspond with very high spatial frequency components, the very existence of a dead or hot pixel will result in signal power within the aforementioned window of the sampled output of the imager . . . and the extent of such power will be directly dependent on the magnitude of the discrete optical image that falls in the vicinity of the dead or hot pixel. Apparatus according to the invention detects the existence of power at a frequency of one-half the imager sampling frequency (i.e. at the center of the aforenoted power-vacant window); thereafter, such power is transformed into a correction signal for properly timed algebraic addition to the baseband signal output of the imager.