Two dimensional adaptive comb filter for IDTV with constant peak amplitude response

A recursive adaptive comb filter structure is proposed that is composed of an infinite impulse response (IIR) filter with a peak amplitude response that is independent of the feedback gain (k). This feature avoids signal overloading in the receiver and in the encoder when the selectivity of the filter is high (k factor is high). Two chrominance and two luminance filter responses, in the vertical/temporal plane, are described. When the frame and line k factors of the luminance filter are adjusted separately, asymmetrical responses are obtained. Similar results hold for the chrominance filter. The asymmetrical response improves the temporal or spatial vertical resolution of the TV picture