| 摘要 |
PURPOSE:To attain digital signal processing with a the number of bits lower in degree than that in a case a digital signal processing is applied to the full frequency band of a brightness signal by separating the higher band of the brightness signal, and applying noise reduction processing by means of digital signal processing only to the said higher band. CONSTITUTION:A brightness signal is separated into the higher band including much noise components and the lower band by a high-pass filter circuit 14 and a low-pass filter circuit 15. And the noise is supplied to a noise reduction processing circuit 13 along with the higher band of brightness signal. The circuit 13 A/D converts the said components, then lets a field memory circuit 20a store the data in the unit of field. Based on the output of the circuit 20a, a noise detector circuit 19 detects the noise included in the brightness signal by making use of the field correlation. The detected noise is subtracted from the brightness signal by a noise subtracter 18, and D/A converted by a D/A converter 17. An output from the circuit 13 is added with thc lower band part of the brightness signal separatcd by the circuit 15 by an adder 24.
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