[vtkusers] fitting curve to points

[philipp.batchelor at kcl.ac.uk]

Is the target curve somewhat convex (and 2D)? you could convert the
coordinates to
polar coordinates around the centroid, and then sort the points by polar
angle? even otherwise it might give a good start...or maybe I'm missing
something.
P

On Wed, 18 Jun 2003, Dean Inglis wrote:

> Hi Goodwin,
>
> thanks for the suggestion, but the trick will be to
> deal with the spatial ordering of the points otherwise
> fitting to the points as is gives a zig-zag pattern
> and not a loop.  I'm thinking of starting with a
> perfectly circular loop having the same number of points
> and then transforming (somehow???) them to the target(?)
> centerpath points: maybe vtkLandmarkTransform ?
>
> Dean
>
> -----Original Message-----
> From: Goodwin Lawlor [mailto:goodwin.lawlor at ucd.ie]
> Sent: Wednesday, June 18, 2003 2:22 PM
> To: dean.inglis at on.aibn.com; vtkusers at public.kitware.com
> Subject: Re: [vtkusers] fitting curve to points
>
>
> Have a look at:
>
> /Filtering/Testing/Tcl/closedSplines.tcl
>
> or here on the web:
> http://public.kitware.com/cgi-bin/cvsweb.cgi/VTK/Filtering/Testing/Tcl/close
> dSplines.tcl?rev=1.3&content-type=text/x-cvsweb-markup
>
> HTH
>
> Goodwin
> ----- Original Message -----
> From: <dean.inglis at on.aibn.com>
> To: <vtkusers at public.kitware.com>
> Sent: Saturday, June 14, 2003 5:53 PM
> Subject: [vtkusers] fitting curve to points
>
>
> > I have extracted the center path from a binarized image of
> > the cross section of a leg bone using
> >
> >                              -> vtkImageGradient  \
> > vtkImageEuclideanDistance ->|                      |->
> vtkImageNonMaximumSuppression
> >                              -> vtkImageMagnitude /
> >
> >
> > then extracted the points with
> >
> > vtkImageNonMaximumSuppression -> vtkThresholdPoints
> >
> > I would like to fit a closed polyline to the points,
> > but the points from vtkThresholdPoints are not in a
> > spatially sequential order.  Any ideas how to do this?
> >
> > Dean
> >
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