PURPOSE: To reduce crossmodulation distortion from a luminance signal component to a chrominance signal due to quantization noise and to prevent the deterioration in DG/DP characteristic by separating an analog video signal into a luminance signal component and a chrominance signal component, converting them into digital signals through the use of an A/D converter circuit and adding the signals.

CONSTITUTION: An analog video signal fed to an input terminal 1 is inputted to a Y/C separation circuit 4 via a low pass filter 3 and separated into a luminance signal component Y and a chrominance signal component C and they are fed respectively to A/D converter circuits 5, 6. Outputs of both correction circuits are added digitally by an adder circuit 7 and the result is fed to an output signal to an output terminal 2. The chrominance signal component C does not include a DC component but changes over bipolar regions. Thus, when the input video signal is A/D-converted while being separated into the luminance signal component Y and the chrominance signal component C, it is required to take consideration that the DC component is correctly digitized. Thus, a non-signal level of the A/D converter circuit 6 is biased so that the level is set to a midpoint of a full scale and the digitized signal is outputted as the complement of 2.