[Insight-users] Re: Watershed Labeled image, Mesh, Cell

Luis Ibanez luis . ibanez at kitware . com
Fri, 03 Oct 2003 14:27:06 -0400


Hi Zhao,

This is a very interesting operation, since it provides
a mechanism for moving from pixel-data to model-base
representations.

You may want to start by trying the VoronoiDiagram filter
http://www . itk . org/Insight/Doxygen/html/classitk_1_1VoronoiDiagram2D . html

Note that this implementation is specific for 2D.

You can create ITK Polygon cells with each one of the
watershed regions. What may be tricky is to linearize
the frontiers between regions, since I guess you will
not want to have a mesh node per pixel on the boundary
between two watershed regions.

---

Another possible approach (but that will require some work) could
be to use a Cellular Aggregate and let a colony of cells reproduce
on top your image, each cell being marked by the labels produced
by the Watershed.

After filling the image with bio cells, the colony could be
post-processed to transform all cells in the boundaries of
watershed into epithelial cells, then kill (induce apoptosis)
in any neighbor cell having the same label. This will result
in a colony with a single bio cell per label and links to all the
bio cells on the boundaries.

The Morphogenesis application in InsightApplication could
be an starting point for such approach.
http://www . itk . org/HTML/Morphogenesis . htm




Regards,


   Luis


-----------------------------
Zhao wrote:
> Hi Luis,
> 	
> 	I want to create Mesh and Cell structures from label image generated by WatershedFilter, with a meeting point of more than three regions as a Node, and watersheds between Nodes as Cells. Could you give me a generic indication of how to accomplish this using ITK? You can just tell me what ITK classes I should refer to except for Mesh and Cell. Thanks!
> 	An addiotnal question: form the Mesh and Cell point of view, is it possible to treate a watershed region as a Cell? A watershed region always has an irregular shape with vary number of edges forming it contor.
> 
> Best Regards,
> Zhao        
> 	
>