Problems (scrolling, calibration…) when creating maps from big PNG images

Although I am quite an intensive internet user and forum reader, this is my first time writing in some internet forum. Oruxmaps deserves the happening
First of all, I would like to thank the creators and developers of oruxmaps for this great software. It has already offered me lot of great times in the mountains and I think that oruxmaps does deserve the best support of all of us.
 
I just wanted to share 2 problems that I have been facing for some days when trying to create maps with oruxmapsdesktop out of some Tobacco maps of Alps that I have in PNG image files. Finally, after lot of tries, I have manage to solve these two issues, and I would like to share this with the rest of the Oruxmaps users in case it could be useful for someone:
 
Issue 1:
 
Oruxmapsdesktop collapses when trying to create maps with all the possible multilayers activated (50%, 25%, 12,5%, 6,25%). I guess that this problem was due to the big size of the PNG image files I was using (50MB-100MB).
Solution: to disable some of the layers. In my case, it was enough to disable the 6,25% layer for avoiding the collapse of oruxmapsdesktop software.
 
Issue 2:
 
Once I had created some map for oruxmaps android app and I had pasted the corresponding folder in my mobile, there where various problmes for using this map in the mobile app. The main issue was that when scrolling the map horizontally with my finger, the map moved vertically, and viceversa. Besides, the calibration of the map was significantly moved from its correct position, although correct datum and projection had been used, as well as correct x,y points and coordinates.
Solution: surprisingly, after lot of tries everything was solved once I converted the original PNG images (quite big files, as I already mentioned) into JPG files. Then the whole process for creating the maps with oruxmapsdesktop worked fluently and the maps I obtained did scroll normally on the mobile app and had the right calibration.
 
I don't know about the exact relation between the problems I faced and the solution methods I used. Probably PNG format and big size of image files had something to do with it... However, it worked in my case and I hope that it helps other people for solving similar problems when creating maps.