Abstract: An object of the invention is to provide an image memory system capable of efficiently reading out image data also in case of consecutively reading out image data from an image memory along a direction other than the direction in which a burst access can be performed. In case that a bit-map image is partitioned into square or rectangular blocks and image data of pixels contained in one block are made to correspond to one row space, row spaces respectively corresponding to two blocks being adjacent to each other with a common side between them are made to belong to different synchronous DRAMs without fail and all of row spaces respectively corresponding to four blocks having commonly one vertex are made to belong to different banks.