Can the cropper cropbox show a 'bleed' area?

[catalano]

Is there any way to add say a 20px semitransparent border to the cropbox such that the resulting cropped image includes the outer area of the border? Attached is an example of what I'm trying to achieve. This was done by adding a 20px border to the cropper-view-box class. Unfortunately the resulting crop is not to the outside of the border. Also, in order to even get this to work I had to modify one of the functions in the script to subtract 20 from the translate calculations otherwise the crop box would be offset by the border size. I tried doing the same thing with an inset box-shadow but it just doesn't display. Can anyone suggest a way to achieve this? FWIW, the intended use is for a user to upload/crop an image for print purposes but allow them to insure that the key areas of the photo are in the 'safe' area.