PURPOSE: To improve the performance for detecting the movement of a chrominance signal by using a signal limited only to a band of the chrominance signal, further obtaining the chrominance signal in which a luminance signal component is removed from a band controlled signal by a comb-line filter and obtaining the difference between frames of an absolute value.
CONSTITUTION: A composite color television signal is inputted from an input terminal 1, converted into a digital signal by an ADC2 to take out the signal of the band of the chrominance signal by a BPF3, further, a signal in which the change of the level of the chrominance signal is corrected is outputted from an amplifier circuit 4 for ACC and the demodulation of the chrominance signal is carried out in a demodulation circuit 5. Then, when it is added to a signal delayed by 1H by a 1H memory 7 is an addition circuit 8, the luminance signal in the band of the chrominance signal is removed. The input signal of the memory 7 is delayed by 1 frame in a frame memory 6, a comb-line processing is performed by the output of a 1H memory 10 and an addition circuit 11 and the chrominance signal is extracted. Then, respective absolute values are taken in absolute value circuits 9 and 12, the difference is obtained in a subtraction circuit 13, the absolute value is obtained in an absolute value circuit 14 and further smoothed in a smoothing circuit 15 and the conversion of a bit is performed in a non-linear shape in a converting circuit 16.