[Therion] Resizing or scaling a replacement background image

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