[Therion] Resizing or scaling a replacement background image

[Bill Gee]

I have Inkscape but have never used it for cave cartography.  I do not 
have the Therion plugin for it.  The regular xTherion interface is 
familiar and generally suitable, so I have never felt the need to go 
through another learning curve.

===============
Bill Gee

On 4/4/26 00:54, Axel via Therion wrote:
> Moin,
> scaling (multiple) backgrounds are no problem if u use Inkscape with the 
> Therion plugin (one of the reasons I startet using it)
> I know it has other issues and misses some features u use, but it might 
> be a solution here...
> 
> Axel
> *Gesendet: *Freitag, 3. April 2026 um 19:45
> *Von: *"Bill Gee" <bgee at campercaver.net>
> *An: *"Therion Mail List" <therion at speleo.sk>
> *Betreff: *[Therion] Resizing or scaling a replacement background image
> Hello everyone -
> 
> I am not sure how this should be handled, or if it even CAN be handled ...
> 
> A few weeks ago we went to a section of a cave where the original sketch
> has some problems. Rather than resketch the entire section, we took the
> original sketch and made corrections directly on it.
> 
> Now I want to update the Therion map. Six months ago I used the
> original sketch as the background of a .th2 file, then drew as much as I
> could figure out. Since the update is on the same piece of paper, I
> figured I could just replace the original drawing background with a
> scanned image of the updated sketch. It did not work.
> 
> The new scanned background comes in about 1/5 as big as it needs to be.
> The original elements I drew do not match up, so I cannot draw the new
> stuff on it.
> 
> 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? Is there a way to stretch the new background so it
> fits under the existing drawing?
> 
> It might be easiest to ask for a rescan. The new scan might still not
> line up. Is there a way to shift the background? I think there is. I
> have managed to do it a few times by accident. No idea what keys I hit
> when that happens. I have to close the .th2 without saving, then open
> and start again.
> 
> -- 
> ===============
> Bill Gee
> 
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