Noise filter

摘要

A recursive digital filter is disclosed for removing noise from an incoming television signal. The filter couples the incoming television signal to a subtracter without substantial attenuation of the television signal. The subtracter also receives at an input an attenuated difference signal comprising a selected amplitude of the difference between the incoming signal and an earlier received signal which has been delayed for an interval corresponding to one television frame. The subtracter subtracts the attenuated difference signal from the incoming signal and develops an output in which noise is substantially reduced.