Panning
When the image is larger than the image window, you can pan the image by assigning
the pan tool to either mouse button. Click the mouse button on the image and drag it.
Also, a panning window displaying the full image is displayed top left in the image
window. Click on it with the left mouse button to display that part of the image.

Panning window with visible part in orange rectangle

Panning tool assigned to the left mouse button