PURPOSE: To decide an optimum vector without increasing a hard scale by deciding the frequency of a two-dimensional frequency detecting circuit and detecting a dynamic vector in a block.
CONSTITUTION: When a composite video signal is inputted from a terminal 1, two frames are delayed by frame memories 2 and 3 and inputted to a dynamic vector detecting circuit 6 in a block. One of original signals is sent to a two-dimensional frequency detecting circuit 4. A deciding circuit 5 decides whether or not one period of a frequency is half or below of the length in the horizontal and vertical direction of the block and the signal is outputted to the circuit 6. At the circuit 6, the minimum value of the dynamic vector is outputted to a signal line (a). At a dynamic vector deciding circuit 7, the optimum dynamic vector of a group or zero is outputted as the dynamic vector.