Noise reduction circuit of a video signal.

摘要

A noise reduction circuit for a video signal recording and/or reproducing apparatus comprises a high pass filter (4) for extracting high frequency signal component form the input luminance signal, a limiter circuit (5) for limiting the high frequency signal component, a multiplier (7) for determining the degree of preemphasis and/or deemphasis by multiplying the limited signal, and summing and subtracting circuits (2, 3, 19, 20) respectively for adding and subtracting the high frequency signal component processed by the limiter circuit and the multiplier to and from the original luminance signal. The limiter circuit has an amplitude characteristic which changes a gradient so as to have a characteristic curve of at least three different gradient slopes interconnected in succession with an increase in amplitude of the signal supplied thereto.