To checks the destruction and secular changes of image data on a removable storage medium of an external storage device and an error in their read from the storage medium even without information on which information to be written to the external storage device is based.
When the image data are written from an HD 75 in a main body to a medium 76C of an external CD drive, the check sum of the image data is stored as management information on the CD (medium) 76C and when data are read out the CD 76C and written to the HD 75 to the contrary, whether the data on the CD has an error is checked by matching the sum of the image data expanded in an image memory 66 after the writing to the HD with the check sum as the management information stored on the CD.
HATTORI YASUHIRO
SHIMIZU YASUMITSU
OKAMURA TAKAO
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