Using Xara Photo & Graphic Designer 17, with photo documents, the perspective correction feature naturally leaves some uncorrected edge that needs trimming. How do I trim it? If I save the photo it is not automatically trimmed to leave only the good part.

To explain a little further: At the end of the perspective correction there is an inner border (the good part) and an outer border (the original photo). I thought I might have to manually clip, shoving the outer border to match the inner, but as soon as I click on the outer one the inner one becomes invisible, so this is not possible.

I expected some simple device like double-clicking inside the corrected portion but if there is a simple device I haven't managed to find it. The help file information ends with the use of the perspective correction button, as if the outer part were trimmed automatically (I think perhaps it used to be but it is not now).