Mouse

Top

In Zoom mode

Left Click        

Increases the apparent size of objects in the viewport (Zoom-In).

Right Click        

Decreases the apparent size of objects in the viewport (Zoom-Out)

Stretches the chosen area up to the sizes of a Display Window.Click and move mouse to select the rectangle.

In Scroll mode        

Navigate the image with a left click and mouse movement.

In Select mode        

Navigate the image with a left click and mouse movement.

Click and move mouse to select the rectangle.

SHIFT key allows to select multiple regions. Pressing ALT the selection maintains aspect ratio.