6 Undo and Redo

Probably the first thing you will notice is that ImageJ does not have a large undo/redo buffer. Undo (Edit▷Undo [z]↓) is currently limited to the most recent image editing / filtering operation. With time you will appreciate that this is necessary to minimize memory overhead. Nevertheless, with IJ 1.45 and later, Undo [z]↓ is, in most cases, undoable and can be applied to multiple images if Keep multiple undo buffers is checked in Edit▷Options▷Memory & Threads…↓

If you cannot recover from a mistake, you can always use File▷Revert [r]↓ to reset the image lo its last saved state. For selections, Edit▷Selection▷Restore Selection [E]↓ can be used to recover any misdealt selection.

In ImageJ the equivalent to ‘Redo’ is the Process▷Repeat Command [R]↓, that re-runs the previous used command (skipping Edit▷Undo [z]↓ and File▷Open… [o]↓ commands).