PURPOSE: To fetch a plurality of data with one scanning and to process the data in a short time, by splitting the screen into an arbitrary number of longitudinal blocks and processing the data in block unit.

CONSTITUTION: The video signal S1 such as TV video data is fed to the comparator 12, the threshold value from the microcomputer 10 is fed to another input via the D/A converter 11, and the video signal binarized is output from the comparator 12. The signal binarized is fed to the shift register group 13, and the screen is sequentially fetched to the shift registers 13-1W13-4 according to the movement of the scanning point of one block splitting the screen into longitudinal blocks, and the video data fetched is transferred to the memory 27 in the computer 10 corresponding to the entire screen. The block designation signal and the line designation signal are fed to the control section 14 from the computer 10, the video data in one block is sequentially located to the memory 27, this operation is sequentially made for every block.