In an image data conversion device having an image data memory for storing and outputting picture element data to provide reproduced images according to a DMA transmission system, address output means provides address data to specify memory addresses in the image data memory means in a predetermined order. Conversion means, in response, applies to a memory address to the image data memory means which may be different from the memory address specified by the address data, so that, for instance, the addresses of picture element data are directly changed in the DMA transmission.