Crop allows the user to use the mouse to size and position a crop-rectangle. The anaglyph and interlaced modes are displayed in a single window, side-by-side and above/below in two windows and adjustment and Chromakey in three windows.

Crop-rectangles are displayed over the images in all windows and they move in unison.
After selecting this option and using the guide-lines, position the cross-hairs at the desired top-left position for the crop-rectangle and then hold-down the Left mouse button.
KEEPING THE BUTTON DEPRESSED drag the cross-hairs to the desired bottom-right position for the crop-rectangle and release the button.
The rectangles positions may then be altered by positioning the 'move' cursor over either one and dragging the mouse with the left button depressed.
On releasing the button, the images will be immediately cropped.