[gdal-dev] Thin Plate Spline

[Jan Hartmann]

Hi,

I'm rubber-sheeting old, deformed maps using the thin plate spline 
option of gdalwarp (-tps). My impression was that the control points 
would be transformed to exactly their georeferenced locations, but in 
the georeferenced image the control poimts don't quite align with the 
gcp-coordinates I specified. I'm only using five points per map, so 
could this be the problem? If so, how many points do I need to get the 
control points on their exact location? Or are there other ways to 
achieve this?

Jan