PURPOSE: To easily obtain a TV system converter which has an electronic beam function and a TV system exchange function by performing the scanning line conversion processing and the picture image conversion processing in a mode in accordant with the magnification of an electronic beam.

CONSTITUTION: The input terminals N of the changeover switches 6, 7 and 14 are selected for acquisition of the NTSC system image signals. In this case, the output data of an A/D converter 4 are written into a and field memory 8 in an NTSC system and then, read out in the reference signal timing of the NTSC system. Meanwhile, an input terminal P is selected for acquisition of the PAL system image signals. The weighting coefficients are previously and separately prepared in both NTSC and PAL systems for interpolation required between a scanning line and a picture element. Then, the input terminals P or N of the changeover switches 25-50 and furthermore an input terminal NOR (NORMAL) or ZOOM are selected for acquisition of a desired weight coefficient.