Canon 10D User Guide (en)

Performing Automatic Dust Erasure Processing
The Dust Delete Data that is appended to images shot with the camera 
that can attach this data, can be used to automatically erase dust spots. 
In the main window, select an image appended with 
Dust Delete Data.
Select the [Tools] menu   [Start Stamp tool].
The copy stamp window appears.
When the image has redrawn itself, click the [Apply 
Dust Delete Data] button.
Dust spots are erased in a single operation.
Click the [OK] button to return to the main window.
The [
] mark 
 is displayed on an image from which dust 
spots have been erased.
The dust-erased image can be reverted to its original condition 
at any time
A dust-erased image is displayed or printed as a dust-erased image. 
However, since the dust on the image is not actually erased, you can 
always revert to the original image by clicking the [Undo] button in the 
copy stamp window or performing the “Re-Editing an Image” 
Checking dust erasure in the copy stamp window
Check dust erasure in the copy stamp window. Images before dust 
erasure are displayed in other windows and you will be unable to 
check them.
Printing dust-erased images
You can print as a dust-erased image by printing it in DPP.
The [Apply Dust Delete Data] button cannot be clicked
Even with an image that has Dust Delete Data attached to it in the 
camera, if there is no dust to remove by DPP from the image, the 
[Apply Dust Delete Data] button will be disabled.
To erase dust spots that cannot be erased with the automatic 
dust erasure processing
In automatic dust erasure processing, dust spots are erased based on 
information relating to dust saved in the Dust Delete Data. However, 
there may be cases where you will not be able to erase dust spots 
depending on the type of dust. If this occurs, erase those dust spots 
using the repair function 
 or the copy stamp function 
The image becomes a dust-erased image when converted and 
The dust-erased RAW image actually becomes a dust-erased image 
when converted to a JPEG or TIFF image and saved 
About dust-erased images