There are two tools used to change the current view; Zoom and Pan. These tools alter the way the image is presented; they do not change the image itself.
The Zoom Tool is used to magnify (or enlarge) the view, or to reduce (or shrink) the view.
Use the Left Mouse button to zoom in on the canvas. The Right Mouse button zooms out.
The individual zoom levels are predefined and are not customizable.
The Mouse Wheel used in conjunction with the Ctrl key duplicates the action of the Zoom Tool.
When the Zoom Tool is active, clicking and dragging a rectangle will maximize the specified area in the Editing Window.
When the Zoom Tool is active, pan the canvas by holding the Mouse Wheel down and dragging.
Pan H [temporary activation: hold the spacebar down]
The Pan Tool allows the user to scroll or pan an image.
This is particularly useful when navigating an image larger than the Editing Window (when zoomed in).
Click and drag the canvas to move it around within the Editing Window.
The functionality of the Pan Tool is available when any other tool is active.
Hold down the Spacebar and click and drag to pan the image.
Scroll the image vertically at any time using the Mouse Wheel.
Hold down the Shift key to swap the direction of scrolling to horizontal.
From version 4.0.10+ it is possible to scroll or pan an image past the edge of the editing window.
To disable Overscrolling, open the Settings dialog and untick the checkbox in the User Interface tab.
The amount of panning/scrolling is dependent on the view size of the image. Small images can be scrolled or panned until they are half off screen.
Images viewed at larger sizes can be scrolled or panned until the edge of the canvas meets the center of the Editing Window.
Images can also be panned with the keyboard arrow keys ↑←↓→ while the Spacebar is held down.
The amount of panning performed with the arrow keys and Spacebar varies inversely with the view size/Zoom amount.
Images viewed at high magnification (above 1000%) are scrolled by fractions of a pixel with each key press.
Images being viewed at low magnification levels are scrolled by multiple pixels per key press.
If both the Ctrl key and Spacebar are held down the amount of panning per arrow key press is increased by a factor of ten.
Centering an Image
Centering can be achieved by using the keyboard combination Ctrl + B twice.
The first combination zooms the image to the Window, the second combination restores the previous zoom level.
The same effect can be achieved using View > Zoom to Window twice.