I want to make a modern relief map with DEM and an old scanned map. So, I want warp the scanned map it to fit modern data. But I want to do it inversely: warp modern data to fit an inaccurate old map. The point is that when I georeference the old map and save the GCP table (*.points), I rewrite the file extension to *.csv format so that it can be edited. For example, I have already tried to exchange the x/y pixel coordinates with the geographical coordinates and rewrite the file extension to *.points. In such cases, the file can be used, but the end result is always complete madness. I tried quite a few combinations.
How do I apply the GeoTIFF elevation model to the old map? How do I tell QGIS not to bend the scanned image to the DEM, but the DEM to the scanned image?
