You can undo single or multiple actions as you edit an image. For example, you can undo brushstrokes, color adjustments, or effects that you have applied to the image. You can also redo single or multiple actions to reapply commands that you have undone.
You can also revert to the last saved version of the image.
The History palette lets you undo and redo actions selectively, regardless of their sequence.
Important! The Undo control does not undo the following actions: renaming files, saving files, opening and closing files, emptying the Clipboard, making changes that are program-wide and not specific to the current image (such as changes to color settings and preferences), or using commands that do not change the image pixels (such as zooming or scrolling).
Undo and redo controls on the History palette
You can undo multiple actions, as well as specific actions, by using the History palette. The History palette lists all actions performed on the active image. The most recent action is at the top of the list, and the first action performed is at the bottom of the list. Unlike the Undo and Redo commands, the History palette lets you undo or redo actions selectively, regardless of their sequence.
By default, the History palette lists the 250 most recently executed commands on the active image. You can set the Undo preferences and specify a higher or lower number of commands.
The table below lists the Undo/Redo controls on the History palette.
Undo to Here
Undoes the selected action and all subsequent actions. Clicking this button is equivalent to clicking an item’s eye icon. The undone actions are denoted by a blank box .
Redo to Here
Redoes the selected action and all undone actions preceding it. Clicking this button is equivalent to clicking an item’s yellow-X eye icon.
Undo Selected
Undoes a selected action. Clicking this button is equivalent to holding down Ctrl and clicking an item’s eye icon. Note: Undoing a selected action may interfere with subsequent actions and produce unintended results.
Redo Selected
Redoes a selected action. Clicking this button is equivalent to holding down Ctrl and clicking an item’s red-X eye icon.
Clear Selectively Undone Commands
Converts all selectively undone actions into commands that can no longer be undone or redone. You are prompted to confirm the performance of this action.
Show Non-Undoable Commands
Shows or hides the non-undoable commands. When shown, non-undoable items are grayed out.
Empty Command History
Converts all History palette items into non-undoable commands. You are prompted to confirm the performance of this action.
If you want to undo multiple actions, repeat the EditUndo command.
The Undo command undoes multiple actions in the order in which they were performed. To undo actions selectively, you can use the History palette.
If the action cannot be undone, the Undo command is unavailable.
You can also undo an action by clicking the Undo button on the Standard toolbar, or by pressing Ctrl + Z.
To redo an action
Edit workspace
• Choose EditRedo.
The Redo command redoes multiple actions in the order in which they were undone. To redo actions selectively, you can use the History palette.
Only actions that have been undone can be redone.
You can also redo an action by clicking the Redo button on the Standard toolbar, or by pressing Ctrl + Alt + Z.
To revert to the last saved version of an image
Edit workspace
• Choose FileRevert.
To undo and redo actions by using the History palette
Edit workspace
• Choose an action on the History palette, and then perform one of the following actions.
To
Do the following
Undo an action
Click the Undo/Redo button for the selected action, or click the Undo to Here button . The undone actions are denoted by a blank box .
Redo an undone action
Click the Undo/Redo button for the selected action, or click the Redo to Here button . The selected action and all preceding actions are redone and no longer appear as blank icons. Note that selectively undone actions (denoted with a gray X) that precede the action you clicked are not redone. These actions can be redone only with the Redo Selected command.
Selectively undo an action
Hold down Ctrl, and click the Undo/Redo button for the selected action, or click the Undo Selected button . Selectively undone actions are denoted by a gray X.
Redo a selectively undone action
Hold down Ctrl, and click the Undo/Redo button for the selected action, or click the Redo Selected button .
To set Undo preferences
Edit workspace
1 Choose FilePreferencesGeneral Program Preferences.
2 From the left pane, click Undo.
3 Make sure that the Enable the undo system check box is marked.
Note: This check box must be marked if you want to undo actions in images that are currently open. If the check box is not marked, you cannot undo any actions in an open image after you click OK in the Preferences dialog box.
4 Mark or unmark the following check boxes:
• Limit undo/redo disk usage to n MBytes of storage per open image — lets you specify the amount of hard disk storage available for Undo/Redo operations by typing or setting a value in the control. The storage space needed depends on the current image size and the type of operations you’re performing. If you have a large amount of unused disk space, you don’t need to mark this option.
• Limit undo/redo to n steps per open image — lets you modify the default value of 250 steps. Decrease the value in the control if your unused disk space is less than 500 Mbytes.
• Enable Fast Redo — lets you set the Redo command to work at optimal speed. Do not mark this option if you want the Undo command to work at optimal speed.
5 Type or set a value in the Non-undoable steps in the History Palette control.
This value specifies the number of non-undoable steps (steps that cannot be undone or redone) that are retained after the Undo/Redo limit has been reached. The default value is 10.
Non-undoable steps cannot be undone or redone. However, they can be reapplied to the current image or to other open images, saved to a Quickscript or to a regular PspScript file, or copied to the Clipboard.