A control circuit includes a data reduction decoder and an interpolating filter, the data reduction decoder having an line memory for the video signal included in a scanning line. The interpolating filter cooperates with the line memory and includes a first adder, a subtracter, a first and a second multiplier, and a second adder. The control circuit controls the writing of digital signals of a field corresponding to any of the conventional television standards into a memory array and the readout of digital signals at an increased field rate, preferably at twice the field rate.