Noise reduction circuit

Abstract

Abstract PURPOSE:To eliminate surely color blur in vertical direction when the S/N ratio of a chrominance signal is improved by opening a feedback loop of a noise level setting circuit to increase the noise reduction effect at vertical non-correlation. CONSTITUTION:A correlation switch 6 is provided to an output stage of a subtractor 12 and also an output of the correlation switch 6 is fed to a 1H delay element 9 and an adder 14. Thus, a noise component SN in a chrominance signal SC is eliminated at vertical correlation, the S/N ratio of the chrominance signal SC is improved and the correlation switch 6 is operated at vertical non-correlation, the feedback loop of the noise level setting circuit 8 is opened and a noise component SN' is not added to a video signal SI on a main line, then no color blur in vertical direction is generated.

Inventors

• 👤 Ichitaro Sato
• 👤 佐藤　市太郎

Bibliographic Details