Design problems makes it unusable

I really want this plugin to work. It’s unusable if the original image is large, however. It presents a full-size pixel-per-pixel image on which you’re supposed to place a crop rectangle. That image is so large, however, that you cannot make the crop rectangle large enough to surround the area you want to use as the thumbnail. To make this plugin usable, the displayed image must be scaled to fit in the edit window. Scroll bars on the edit window are just unacceptable.