PURPOSE: To control the write address of each color image data for the following page prior to the transfer finish of each color image data for once page by alternately switching the write address arrangement and read address arrangement of each color image data of an image memory.

CONSTITUTION: A CPU 1 first sets '0' as mode in a flip flop (FF) 8, and then transfers a printing data to a video RAM 5. When the data for one page is stored, '1' is set as mode to the FF 8, and the transfer of the video data is ON. While no video data is transferred in mode 1, the CPU 1 accesses the video RAM 5 and writes the data of Y, N, C, BK to the same address of the address written in the video RAM 5, whereby the Y, M, C, BK data of one picture element are stored in order in the memory. When the CPU 1 finishes to write the following page data after the printing for one page is finished, the CPU 1 sets '0' as mode in the FF 8, and starts the data transfer of the following page.