Key and Button Summary

Arrow keys to move a reference point (end or corner) one pixel in the reduced image.
Shift plus arrow keys to move 5 pixels in the reduced image (coarse step).
(only with Snoop) Ctrl plus arrow keys to move one pixel in the full image (fine step).

Cursor in the image subwindow:

Middle mouse button to capture and drag a reference point (end or corner).
Right mouse button for main menu.

Tab key to change the movable reference point (end or corner).

Cursor over the color scale:

Numeric key pad +/- to adjust gray/color scale ceiling.
Shift key plus key pad +/- to adjust the scale floor.
In either case, the + key brightens the image.

Cursor in the cut subwindow:

Middle mouse button for hairline cursor.

Cursor in the zoom subwindow:

Numeric key pad +/- to extend or shrink the magnified spot.

Cursor in the surface subwindow:

Left mouse button to rotate.
Middle mouse button to translate.
Right mouse button to zoom.