Undo Raster Edit
Undo Raster Edit will revert an Image back to its original form
(both on-screen and source) from changes made by: Image Cut, Image
Crop, Remove Speckles, Trace Line or Trace Polyline. It will not
remove any polylines created by Trace Line or Trace
Polyline.
Pulldown Menu Location: Raster > Undo Raster Edit
Keyboard Command: rasundo
Prerequisite: an Image that has been edited