[Gdal-dev] Convert data from Projected to Modified system...

[jason]

Bear with me since I am by no means a GIS person or the like.  We have data in a
known projected system (ie: stateplane, think thats right) and we need to
transform it to a cartesian system (modified?).

I know the x/y offsets, scaling and rotation to go from the old to the new system.

The data is in a TIFF format and I was hoping to be able to use gdal or
mapserver to reproject it and dump out a new file in which only the coordinates
have changed and the shape of the TIFF etc accordingly.

I presume via gdal I can specify something like "+k=1.000202
+x_0=-1398448.885932 ..." and so on.  I am not sure this is possible but if I am
on the right track I am unsure precisely how to apply the known transformation
parameters via this method and was hoping someone might be able to point me onto
some documentation or examples as to how this can be done.

Thanks.