[Insight-users] WaterShed Segmentation of grayscale images

[Joshua Cates]

Hi Neha,

The same pipeline can be used for scalar images.  Simply use the scalar
versions of the same filters.  (i.e. instead of the vector anisotropic
diffusion, use the regular anisotropic diffusion.  Instead of the vector
gradient magnitude, use the regular gradient magnitude.)  As Luis pointed
out, denoising is important to reduce the complexity of data in
uninteresting regions of your image.  Anisotropic diffusion is handy in
this context because it preserves the location and strength of gradient
edges in the image, which are used to define watershed regions.

Josh.

______________________________
 Josh Cates			
 Scientific Computing and Imaging Institute
 University of Utah
 Email: cates at sci . utah . edu
 Phone: (801) 587-7697
 URL:   http://www . sci . utah . edu/~cates


On Tue, 11 Nov 2003, Neha D wrote:

> 
> Hi All,
> 
> I want to use watershed segmentation on raw gray scale images.
> 
> currently i am studying this filter usage in software guide of ITK. In that, example uses vector image as input and applies diffusion filter and gradientMaginitude Filter.
> 
> Pipeline is used as follows:
> 
> caster->SetInput(reader->GetOutput());
> 
> diffusion->SetInput(caster->GetOutput());
> 
> gradient->SetInput(diffusion->GetOutput());
> 
> watershed->SetInput(gradient->GetOutput());
> 
> colormapper->SetInput(watershed->GetOutput());
> 
> writer->SetInput(colormapper->GetOutput());
> 
> For Grayscale RAW images of unsigned  short as input image, 
> 
> what filters do I need to use? Also, why do we need to use diffusion filter? What is diffusion of color images? Do I need to use that filter for grayscale images?
> 
> Any input on this is appreciated.
> 
> Thanks,
> 
> Neha
> 
>  
> 
> 
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