The History palette is available in Home Deluxe and Business versions only. See the feature comparison chart here.
Hint: Users with any licenses (Home/Home Deluxe/Business) can use the Undo/Redo / commands and the History Brush tool .
The History palette shows the list of every change made to a file. By clicking on an item in the list, you can revert the file to a previous state.
You can hide/show this panel by clicking on its title.
At the top of the palette, near a thumbnail of the image, there is information about the file: its name, size (in pixels), color mode, profile, and date and time of creation.
The history of changes is arranged in a linear fashion. This means that if you return to any intermediate state and apply an action, all actions on the list after it will be permanently removed, except for the control points (which will be placed at the top of the list). Selecting Open from the list returns the file to its initial state, as it was when loading to the program (before changes were applied).
All changes made are shown with their corresponding icon. Any successive changes made by the same tool (two or more) are arranged in a group; the number of elements in a group is shown by a grey number to the right of the icon. The list of elements in a group can be collapsed and reopened by pressing the "+" to the left of the tool’s icon.
The following buttons are at the bottom of the History palette:
To rename a checkpoint, double left-click on the checkpoint’s name, enter a new name and press Enter.
You can save the checkpoints with the current state of the image to a file with the .akvis extension.