[vtkusers] bilinear, trilinear interpolation..

[David Gobbi]

On Sun, 1 Jul 2001, K. R. Subramanian wrote:

> David Gobbi wrote:
>
> > I just remembered another method for interpolation: you can
> > use vtkImplicitDataSet or vtkImplicitVolume to convert the
> > data into a function.
>
> Aha!  This perhaps will serve my purpose. So I can set the volume with the
> SetVolume (vtkImageData*) call and then query the volume at any point (x,y,z)
> and it internally interpolates for non-lattice locations, right?
>
> Will it just do linear interpolation? I remember in an earlier email
> that cubic was supported (perhaps for some other classes?)

Cubic interpolation is supported internally in vtkImageReslice, but
nowhere else (as far as I know).  Which is why I mentioned previously
that I'd like to move the interpolation code in vtkImageReslice into
its own imaging class.  Perhaps it could be called 'vtkImplicitImage'
subclassed from vtkImplicitFunction ;)

> Thanks, it amazes there is so much response on weekends -:) ?

It's a lot less than on weekdays!  The weather here is lousy today,
I suppose that can be my excuse.

 - David

> >
> >
> >  - David
> >
> > On Sat, 30 Jun 2001, Will Schroeder wrote:
> >
> > > The cells vtkPixel and vtkVoxel do interpolation. There are more general
> > > forms of these cells that do something similar, although less efficiently:
> > > vtkQuad and vtkHexahedron. Using EvaluatePosition() and EvaluateLocation
> > > you can go back and forth between parametric and world space. Also, there
> > > is a static function InterpolationFunctions that can be used (given a
> > > parametric coordinate pcoord[3], return the interpolation weights).
> > >
> > > Will
> > >
> > >
> > >
> > >
> > > William J. Schroeder, Ph.D.
> > > Kitware, Inc.
> > > VTK-Based Visualization Solutions
> > > 469 Clifton Corporate Parkway
> > > Clifton Park, NY 12065 USA
> > > will.schroeder at kitware.com
> > > http://www.kitware.com
> > > 1-518-371-3971 x102
> > >
> > >
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>
> --
> Dr. K.R.Subramanian                           Phone: (301) 402-0042
> National Institutes of Health                 FAX:   (301) 402-4080
> National Library of Medicine                  Email: krs at cs.uncc.edu
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>