In each of the memory cell arrays in the memory banks, a memory cell row corresponding to each of the word lines extending in a column direction of each of the memory cell arrays store pixel data of each pixel block of first and second rows set in a horizontal way in a search area within a search frame of picture signal. The pixel data of a predetermined pixel block is selectively captured into each of the data buffer through the sense amplifiers and the switches. Selector sequentially extracts pixel data as candidate blocks based on the pixel data of two pixel blocks held in each of the data buffers. The matching circuit matches the pixel data as the extracted candidate blocks against the pixel data as the input reference block using the block-matching process to obtain a motion vector relative to the reference block.