[Proj] Rectification of maps

Frank Warmerdam warmerdam at pobox.com
Thu Sep 22 09:30:59 EDT 2005

On 9/22/05, Thomas Flemming <tf at ttqv.com> wrote:
> Hello,
> I often have maps with unknown projection information but printed lat/lon
> grids. Or papermaps, which have strong deformations so that after scanning the
> projection does not fit anymore.
> Is there a way in proj to calculate x-y/lat-lon by defining a couple of known
> referencepoints ?


It seems like what you would want is a rubber sheeting transform
of some kind based on a bunch of reference points.  Two reference
points wouldn't give you much information.  PROJ.4 does not
address this issue.  I do have such a capability in GDAL -
underlying transformations based on reference points and a way
of applying it to resample rasters.

Best regards,

I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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and watch the world go round - Rush    | Geospatial Programmer for Rent

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