Image memory

An image memory has a random access memory array (1) capable of being randomly accessed; a serial access memory array (2) partitioned into n power of 2 (n > 1) divisional areas cyclically and serially accessed in asynchronism with the random access memory; data transfer unit (3) for transferring data between the random access memory array and the serial access memory array; a determined unit (4) for determining a row of data to be transferred from the random access memory array to each of the divisional areas; and a designating unit (5) for designating at least one of a top serial access address and a last serial access address respectively of each divisional area, wherein the data transfer unit (3) executes data transfer from the random access memory array to the serial access memory array in accordance with outputs from the determining unit (4) and the designating unit (5).