PURPOSE: To realize the interpolation processing of picture data at a high speed synchronously with a TV sweep frequency with comparatively simple configuration.

CONSTITUTION: Interpolation data interpolating between data for adjacent two picture elements are stored in advance to 1st, 2nd and 3rd ROMs 10a, 10b, 14 respectively and the 1st and 2nd ROMs 10a, 10b use source data by adjacent two picture elements in the column direction for a read address and the 3rd ROM 14 uses source data by adjacent two picture elements in the row direction or adjacent interpolation data in the row direction for a read address. Then the interpolation data outputted from the ROMs 10a, 10b, 14 and the source data are arranged sequentially for each row by a data arrangement output means 6 and the arranged data are outputted.