Provided is a motion estimation device in which an amount of pixel data transferred from an external frame memory to an internal reference local memory is reduced. By the motion estimation device, it is possible to reduce a memory capacity and a size or processing of a circuit controlling the pixel transfer. In a reference memory control unit and an internal reference memory, a height of a area to be updated is set to L pixels, where L is power of 2, a logical address segments, whose size is suitable for address calculation, are allocated to picture space, and FIFO management is performs. In another application, an assistance memory is added, and another element other than the assistance memory performs the FIFO management for rectangular areas in an image of a conventional width. As a result, the address calculation is simplified, which makes it possible to reduce an embedded circuit for the reference memory control unit and the internal reference memory.