[IGSTK-Users] Question on Mesh representation

[Ofer Eliassaf]

Hi Patrick,

First of all thank you for your reply.

Now for the answers and questions...:
I created a mesh using the marching cubes method.
The marching cubes gets a binary image and construct a mesh out of this image.
This image was in the image coordinate system (i.e. pixel in the input
0,0,0 represents
 pixel 0,0,0 in the binary image).

I then wanted to display the output mesh in my GUI but the mesh and the image
were not aligned.

I understand that there is something here that I miss - regrading the
image coordinate
 system?

>From your question I understand that I should go over the mesh point by point
and apply a transform on my points?
How can I get this transform?

I understand that applying transform on the igstk::mesh directly is
influencing only display3d and not display2d, am I right?


Thanks,
Ofer





2007/6/26, Patrick Cheng <cheng at isis.georgetown.edu>:
> Hi Ofer and Yoav,
>
> 1. You might find this thread in Insight-User list very helpful.
> http://public.kitware.com/pipermail/insight-users/2003-September/005006.html
>
> 2. If the mesh is being given in the image coordinate system, then the
> image slice should overlaid with mesh. When you segmented the image to
> get the mesh, did you use the physical point (take origin and spacing of
> the image into consideration)?
>
>
> Patrick
>
> Ofer Eliassaf wrote:
> > Hi there,
> >
> > I am new to igstk. I wrote a program for liver segmentation.
> > I am using the igstk for representing my CT images using NeedleBiopsy
> > example.
> > I wrote my algorithmic code in itk and my algorithmic output is a mesh.
> > I have 2 question regarding igstk::mesh:
> >
> > 1) Is there a way to transfer my itk::mesh into igstk mesh in a quick way
> >    by using a constructor or something like that?
> >    So far I am copying my itk::mesh point by point - triangle by triangle.
> >    This is a overhead to me.
> >
> > 2) When I am showing my igstk::mesh in my windows it is not synchronized
> >    with the CT image. I want it to be one on top of the other so the
> > user will be able to
> >    see the segmentation result.
> >    (I am using  igstk::View2D classes as suggested in the needle biopsy
> >      and what i get so far is that the mesh is shown in a different
> > place inside
> >      the display window).
> >
> > Thank you very much,
> > Ofer
> >
> >
>
>
>


-- 
Regards,
Ofer Eliassaf,
ofer.eliassaf at gmail.com