Patent ID: 6201583
Filing Date: 2001-03-13
Classification: H04N

Abstract:
An image signal input apparatus for inputting to a processing unit an image signal formed by superimposing a brightness signal on a color subcarrier wave having a generally sine waveform, the apparatus comprising:a brightness signal extracting unit that extracts the brightness signal from the image signal,an output unit that outputs the extracted brightness signal to the processing unit, anda sampling unit that samples the image signal at a sampling frequency to produce a sampled image signal, wherein the brightness signal extracting unit extracts the brightness signal from the image signal based on the sampled image signal andthe brightness signal is superimposed on the color subcarrier wave using a quadrature two-phase modulation method, an amplitude modulation method or a phase modulation method;the sampling unit samples the image signal at the sampling frequency that is a multiple of a frequency of the color subcarrier wave; andthe brightness signal extraction unit extracts the brightness signal by determining a mean value of the sampled image signal.