[Qgis-user] georeference intersecting lines of highway

[Greg Troxel]

Garth Fletcher via QGIS-User <qgis-user at lists.osgeo.org> writes:

> I think you have to know the projection used for the printed map, and
> then set that layer's CRS to match.
> Then you can convert ("warp") it to your preferred (project) CRS.
>
> The problem is that different projections distort the map in different
> ways, for example conical vs mercator projections.
> In such cases if you simply import a conical projected map, say of
> Massachusetts, as a raster into your transverse mercator project, say
> for New Hampshire, the result will be doubly distorted...

A fair point.

I was thinking of large-scale maps and conformal projections, which are
probably more forgiving.