[vtkusers] ImageReslice and Interpolation Can anyone help?

[Janny Dong]

David,

Thanks a lot for your quick and helpful replies. So if I use axial view, the
output image slice is on x-y plane so that it's a 2D image, and the slice
position is the origin of the image, correct?

Janny

On 6/14/07, David Gobbi <dgobbi at atamai.com> wrote:
>
> Hi Janny,
>
> If you are trying to display a single 2D slice, then the axial view is
> the only view that will show an image.  The other views will just
> display a vanishingly thin line.
>
> I have attached an image that goes a small ways towards explaining the
> reslice orientation matrices.  The first two columns of the matrix
> describe the orientation of the slice plane.  The third column must
> always be set to the cross product of the first two columns.  The fourth
> column is set to a point that you want the slice plane to pass through.
>
> The matrix is the geometrical transformation from the reslice output
> image coordinate space to the input image coordinate space.  Describing
> the columns in terms of slice orientation and position are just a useful
> mathematical trick that can be used to fill in the matrix values.
>
> - David
>
>
>
> Janny Dong wrote:
> > Hi David,
> >
> > Yours is probably the quickest reply I've got so far through this
> > list. Thanks again! Now I know how vtkProbeFilter works. Looks like I
> > have to figure out a way to interpolate my data outside VTK. I am
> > considering getting all the data available and then use
> > vtkImageReslice, since it provides several choices of interpolation
> > method.
> >
> > Could you explain a little bit of the Matrices for axial, coronal,
> > sagittal, oblique view orientations part in your example code?
> >
> > //static double axialElements[16] = {
> >   //         1, 0, 0, 0,
> >   //         0, 1, 0, 0,
> >   //         0, 0, 1, 0,
> >   //         0, 0, 0, 1 };
> >
> >   //static double coronalElements[16] = {
> >   //         1, 0, 0, 0,
> >   //         0, 0, 1, 0,
> >
> >   //         0,-1, 0, 0,
> >   //         0, 0, 0, 1 };
> >
> >   static double sagittalElements[16] = {
> >            0, 0,-1, 0,
> >            1, 0, 0, 0,
> >            0,-1, 0, 0,
> >            0, 0, 0, 1 };
> >
> >   //static double obliqueElements[16] = {
> >
> >   //         1, 0, 0, 0,
> >   //         0, 0.866025, -0.5, 0,
> >   //         0, 0.5, 0.866025, 0,
> >   //         0, 0, 0, 1 };
> >
> >
> > I don't quite understand the four different view orientations. Last
> > time I tried axial view and got the first image in my email. I got a
> > blank scene with other view orientations.
> >
> > Thanks,
> > Janny
> >
> >
>
>
>
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