[mapserver-users] help with converting tiff to a shp file

[Sandor Csaba]

Hi, this is not a Mapserver question I think. You have to transform the 
tiff using some image referencing software like ArcView Image Analysis or 
cheaper Stretch Image extension (or any other) before entering it to a 
Mapserv application. This will make an affine transformation (rotate, skew 
and pan) to the image based on the control points you define (image 
coords->map coords) and also create the corresponding world file. Naturally 
some remaining error will be present.

I do not know of any piece of software that does this in runtime, though it 
should not be too complicated to code an affine trafo, but this way you 
have to process the image on the fly which might take quite a while 
thinking of normal resolution scanned arial images or satellites (some 
hundreds of MBs).

I can do the transformation for you like, but please before sending me 
100MB tiff through email please let me know beforehand.

Csaba

At 19:24 2002. 08. 27.t Converted:  -0400, woodbri at swoodbridge.com wrote:
>Or another way to think about the problems is:
>How could you come up with a world file for the tiff, if you know the
>lat/long of the end points of the four runways. So if you know the
>lat/long of eight pixels in the TIFF what would you have to do to
>make a world file?
>
>Anybody have a clue?
>
>-Steve
>
>On 27 Aug 2002 at 16:55, Grant Marblestone wrote:
>
> >
> > I have a tiff (top image) of an airport, and thanks to steven
> > woodbridge, i also have a shp file with the runways of this airport.
> > I wish to convert the tiff to shp using perhaps the shp file i have
> > of the runways to line it up. Anyone here have any experience with
> > this and an easy way to do this? I know it wont be exact but i am
> > hoping to get as close as possible this way.
> >
> > Thanks for any input you can provide,
> >
> > Grant


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