Drag slider to '+' end to zoom in to, and '-' end to zoom out from the image shown
in the central panel.
Central panel
Displays region from the active plane. Use the thumbnail images to the left and
the 3D navigation cube to move through the 3D volume. The radio buttons to the left can be used to change
the orthogonal view shown. The zoom slider on the right can be used to adjust the level of zoom. Left
clicking on the image will shift it to the center of the panel.