What about using imagemagick to resize the new image? magick new_sketch.jpg -resize 2550x3300! fixed_sketch.png Henry On Fri, 3 Apr 2026 at 18:53, Bill Gee <bgee@campercaver.net> wrote:
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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