To eliminate write errors by writing X-ray images which are so digitized that the write errors are substantially removed on a compact disk.
After an image process is completed, a 1st microprocessor 130 instructs image processing software to store digital representation on a 1st computer-readable storage medium 150 and then sends the signal stored on the 1st storage medium 150 to a 2nd microprocessor 140 after all images are completely stored. The 2nd microprocessor 140 instructs the 1st storage medium 150 to transfer data to a 2nd computer-readable storage medium 170. Finally, the 2nd microprocessor 140 instructs the transfer of the data in the form of a bit stream which is continuous and uninterrupted from the 2nd storage medium 170 to compact disk writers. Each writer writes the same data sequentially on two disks.