Just a little update again with the progress of this morning. Using GDAL I got the geo-referenced background image loaded into gPoly. Until now it works quite good, but I think I will have to optimize the code a bit more to work better with bigger background images. Also I will have to add some functionality to make the image geo-referenced if it is not so already, not everybody has access to GeoTIFF files I guess. So there is still enough to do…