[Therion] Resizing or scaling a replacement background image

[bruce at tomo.co.nz]

> I think the reason is that the original background and the new background
were scanned at different resolutions.  I did not scan them. 
The old background image is 2550x3300 pixels and the new is 908x1200 pixels.

>What do you suggest?  ...
Rescan the original with the same settings originally used (preferred), else
use a tool to resize the image, as suggested by others (likely to not be
perfect).

The new scan might still not line up.  Is there a way to shift the
background? 
It likely will not.  Double right-click and drag allows you to move the
background image. 

Bruce