A vertical impulse detecting circuit 104 detects the difference between a level of data of a present horizontal line of an input composite picture signal and a level of data of each of a horizontal line a plurality of lines ahead and a horizontal line a plurality of lines behind. Either an output signal of a three-line chrominance signal separating circuit 100 or an output signal of a horizontal chrominance signal separating circuit 101 is selected as a chrominance signal (CC) that is supplied to a subtracter 105 according to an output signal of the vertical impulse detecting circuit 104. <IMAGE>