You can use various GIS programs and I think there are some older posts here about creating Custom Maps (mainly for Garmin, but these can work with Oruxmaps)
In the past I have used MOBAC or OK Map Creator which I find a little easier to use than some of the GIS programs.
With OKMap Creator you can calibrate the your jpg map with known reference points, and it will georef the map and save it as a raster map. If you use Oruxmaps OKMap creator will output to Oruxmaps format, but will only get 1 zoom level.
If you use Oruxmaps Desktop or Mobac, you can use the OKMap Created file and use it to create a map with multiple zoom levels
I was going to type up instructions but found
billw's post while looking for the Oruxmap download page at the Oruxmap forums which pretty well explains the process with OKMap Creator. See here
https://www.oruxmaps.com/foro/viewtopic.php?t=5098I haven't used my old version of OKMap Creator for a while, and my old laptop's internal power supply died and I can't get it fixed. Shame as the laptop had all my old Map creating software that now doesn't work on 64bit Windows 10.
BTW, what maps do you have for Nepal? I had some of the 1:25k maps compiled from 1:50k aerial done in 1992. The other maps I bought in Kathmandu were 1:75k. I haven't found newer maps since the earthquake.
I have previously used some Garmin maps from these fellas who did some good maps for Annapurna, Everest, Helambu/Langtang
http://www.nepal-trilogy.de/index.php/e ... s-gps.html Good mapset but some waypoints are in German, and the last update was in 2015. Garmin maps don't display the best on Oruxmaps, but they give some idea if you want to give these maps a crack.
They look better on Garmins, but this is what they look like on Oruxmaps.
- Nepal Trilogy Maps (Medium).jpg (233.28 KiB) Viewed 18009 times