Set the zoom level
Zoom In: [CTRL +]
Zoom Out: [CTRL -]
Canvas Navigation
Zoom:
Canvas View Modes.
Map View - view and paint only on the segmentation map.
Dual View - view both the segmentation map and output image. Paint on either.
Image View - view and paint only on the output image
Undo and Redo:
Undo or Redo your action.