The invention provides a convenient way of generating image signals on a progressive scanning basis. Multiple image pickup devices used for an interlaced scanning drive and generate chrominance signal DGi on the interlaced scanning basis with an interlace field and chrominance signals DRi and DBi on the interlaced scanning basis with opposite interlace field. Scanning converter receives the chrominance signal Dgi, DRi and Dbi. The scanning converter then performs an interpolation based on the chrominance signals DGi, DRi, and DBi to generate corresponding chrominance signals DGp (DGp-E, DGp-O), DRp (DRp-E, DRp-O), and DBp (DBp-E, DBp-O) on a progressive scanning basis. Signal processor receives the resultant chrominance signals DGp, DRp, and DBp. The scanning converter sums the chrominance signals DGp, DRp, and DBp belonging to a predetermined number of frames to obtain a new set of chrominance signals.