[vtkusers] how to get outline from CT images

[Goodwin Lawlor]

A quick outline:
1. Segment your ct image to a set of binary images (use vtkImageThreshold,
vtkImageIslandRemove)
2. Use vtkMarchingSquares to extract 2d outlines (maybe pre-smooth with
vtkImageGaussianSmooth)
3. Use vtkStripper to create polylines from the unordered lines from MS

Cad package format is a tricky one... vtkSTLWriter doesn't spit out
polylines. If you have AutoCad you can write a VB script to read the
polyline coords and insert them into a scene as a closed spline.

Check which VTK writer/exporter writes out polylines and then see if your
CAD package can read the format

HTH

Goodwin
----- Original Message -----
From: "ljhfdy4" <ljhfdy4 at sina.com>
To: <vtkusers at public.kitware.com>
Sent: Monday, April 22, 2002 11:51 PM
Subject: [vtkusers] how to get outline from CT images


> Hi, friends:
>
> I have a question about how to get the outline from CT images. What I want
to do is extracting the outline of a special tissue like bone or skin from
one slice of CT (threshold may needed). In my idea the outline should be
polyline, but I am not sure which functions can do this work exactly. Also
how can i save the extracted polyline into a format the CAD packages can
read? If impossible, image format is ok too.
>
> Thanks a lot for your help.
>
>
> Ljh
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