We want to be able to define a region by dragging the mouse across the image. That is, record (x,y) on mouse down, and (x,y) again on mouse up. The FF toolbar lets one define a rectangular region in this manner. However, we also want to define circular regions (by dragging from center to circumference). Unfortunately, in normal image viewing, moving the cursor with the mouse button down is used to pan the image.
Is there a way to accomplish this?