Noise reducing system for video signal

摘要

A noise reducing system for a video signal, comprises a vertical pre-emphasis circuit supplied with an input video signal which is to be transmitted, for pre-emphasizing the input video signal and transmitting a pre-emphasized video signal to a transmitting system, and a vertical de-emphasis circuit supplied with a pre-emphasized video signal which is pre-emphasized by the vertical pre-emphasis circuit and is transmitted through the transmitting system, for de-emphasizing the pre-emphasized video signal. The vertical pre-emphasis circuit has a non-linear pre-emphasis characteristic for relatively emphasizing a high-frequency component of the input video signal in a vertical spatial frequency of a picture compared to a low-frequency component of the input video signal, with the degree of emphasis being reduced as the level of the input video signal increases. The vertical de-emphasis circuit has a non-linear de-emphasis characteristic for relatively attenuating a high-frequency component of the pre-emphasized video signal in a vertical spatial frequency of the picture compared to a low-frequency component of the pre-emphasized video signal, with the degree of attenuation being reduced as the level of the pre-emphasized video signal increases.