PURPOSE: To prevent the deterioration of various characteristics of the main track video signal, by avoiding giving the 1H delay to the main track video signal and then producing a vertical contour signal.

CONSTITUTION: The video signal applied to an input terminal 10 is turned into a direct video output signal. This output signal is converted into a digital video signal by an A/D converter 12 and via a low pass filter 23. However, the video signal within a horizontal flyback time receives no A/D conversion, and the video signal containing the video component receives the A/D conversion to be stored in a field memory circuit 14. The digital video signal is written by means of the circuit 14 to perform the storage and readout. Thus the video signal of the main track produces a vertical contour signal with the digital video signal in a different field.