PURPOSE: To enable simple and quick processing, by size reducing or magnifying a digital video information toward the 1st direction and then storing it, and size reducing or magnifying it toward the 2nd direction.

CONSTITUTION: A processing circuit 20 takes a given synchronism with a synchronizing signal LSA, fetches daga Sij with the clock A, and performs conversion as data mkl. A memory device 21 once stores the output information D(mkl) of the processing circuit 20 with the clock B synchronized with the synchronizing signal LSB. A processing circuit 22 takes a given synchronism with the synchronizing signal LSC and fetches the data D(mkl) with the colck C and makes conversion as Omn. The information D(Omn) thus processed is synchronized with the synchronizing signal LSD and transmitted to the next stage with the clock D.