Abstract: A partitioned image processing device executes image processing of large size drawing data using an image memory of small capacity to provide substantially the same processed result as that obtainable by using an image memory with a large memory capacity. An image data input device for inputting the image data; an image memory for storing the image data; and an image processing device for performing the image processing of the image data read in the image memory are provided. The image processing device is designed to partition the image data read-in from the image memory into partitioned regions; to read the partitioned regions of the image data in the image memory so that the portions of the image data in the adjacent partitioned regions partly overlap with each other, and to execute the image processing of each of the partitioned regions.