Abstract: A document input from a scanner is used as input image data and is stored in image memory in page number order. A control unit prints the input image data and receives instruction data showing the cutting edge when cutting on the center line of the printing paper from the input unit. The control unit stores the addresses at which the input image data are stored in an array A; the image processing unit sorts the addresses stored in the first or second half of the array A, based on instruction data shown by the instruction data discussed above, in descending order by page number. The image processing unit alternates and stores in an array B addresses stored in the first or second half of the sorted array A, and in the first or second half of the unsorted array A. The print processing unit prints the input image data, in the order stored in the array B, on both sides of printing paper, and attains printing results as shown in FIG. 1.

Abstract: A document input from a scanner is used as input image data and is stored in image memory in page number order. A control unit prints the input image data and receives instruction data showing the cutting edge when cutting on the center line of the printing paper from the input unit. The control unit stores the addresses at which the input image data are stored in an array A; the image processing unit sorts the addresses stored in the first or second half of the array A, based on instruction data shown by the instruction data discussed above, in descending order by page number. The image processing unit alternates and stores in an array B addresses stored in the first or second half of the sorted array A, and in the first or second half of the unsorted array A. The print processing unit prints the input image data, in the order stored in the array B, on both sides of printing paper, and attains printing results as shown in FIG. 1.