| 摘要 |
PURPOSE:To reduce the noise component at a contour part of a picture by subtracting a retarded video signal from which only a low frequency component is extracted by a low pass filter from an original video signal. CONSTITUTION:An output of a de-emphasis circuit 7 is subjected to 1H delay by a 1H delay circuit 13 comprising a CCD and only the low frequency component is extracted by an LPF 14. An original luminance signal Y and a retarded luminance signal YD are supplied to a subtraction circuit 17 having a line noise cancel section 8 and an edge noise cancel section 16 in common. The line noise cancel section 8 shows a Y comb-line filter characteristic with respect to a small amplitude signal being a difference signal DELTAY and the noise component of the original luminance signal Y is eliminated thereby. The circuit acts like a noise limiter circuit used conventionally, not as a line noise cancel circuit with respect to the high frequency component.
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