[Therion] Scaling problems with backgrounds in th2 files

[John Stevens]

A method I used to copy from a previous survey was to export the centreline as a xvi file. Then take a jpg of the old survey and scale it so the pixel count matches that of the xvi file. 
The next step was to use both images as background images in the th2 file. A bit of adjustment of the position location to make them match then it was simple to copy the old survey. 

Now I cant align the images as the zoom function now changes the scales of the two images differently. If I use a jpg to trace over and zoom in to trace a detailed area the scaling goes off. The resultant lines are to the wrong scale and/or are misplaced.

Is there a way of fixing the scale of a background image so it scales properly. It seems to go wrong with the + – and scroll wheel.

John
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