PURPOSE: To reduce the line flicker of a color difference signal in both of a moving image and a still image.

CONSTITUTION: A memory 26 stores a luminance signal and a memory 28 stores a point sequential color difference signal. Both the memories 26, 28 are respectively provided with one-frame storage capacity. The weighted means of a signal read out from the memory 28 and a current signal is found out by an adder 30 and a 1/2 divider 32 and written in the memory 28. A memory control circuit 52 generates an one-line preceding reading control signal 52a and an one-frame preceding reading control signal 52b to the memories 26, 28 in accordance with horizontal and vertical synchronizing signals. A selecting device 54 controls a switch 56 in accordance with the input of a moving image or a still image. At the time of inputting a moving image, signals before one line are read out from the memories 26, 28, and at the time of inputting a still image, signals before one frame are read out.