[Insight-users] Is there any method in ITK to smooth an 3D object?

[Luis Ibanez]

Hi Rao,

It seems that you are staking slices by
doing 2D/2D registration.

You could perform smoothing with the Median
filter. Set the radius to the size of the
zigzag in your image.  For example, if one
slice is shifted by about 2 pixels with
respect to the next. then use a radius of
2x2x2. Note that the radius in the Median
filter is actually an array of integer
radii.

For details on the Median filter, please look
at the SoftwareGuide

   http://www . itk . org/ItkSoftwareGuide . pdf

Section 6.4.2, pdf-page 159, paper-page 185.

You could also try the anisotropic diffusion
filters that are discussed in Section 6.5.2.

You could play with varying the radius of the
Median, and/or by applying the filter several
time.

Keep in mind that any type of smoothing will
necessarily degrade your image. It is up to you
to determine how much information you are willing
to loose in order to get the smoothness.

Note also that you could delay the correction
of the zigzag effect until after you perform
tasks like segmentation.  It all depends on what
your entire processing is intended to achieve.

BTW, if the zigzag in the slices is more than
one pixel, this actually may be indicating
that your registration still needs some work,
probably fine tunning parameters, or using a
better interpolator (e.g. BSpline).



Regards,


  Luis



-----------------
Rao Jianguo wrote:
> Dear All,
> 
> My question is if we have 2D images roughly registrated. But the
> registrated 3D image still have some zigzags. Does ITK has a
> method to correct the zigzag?  Or a method to smooth it?
>  
> 
> Thanks,
>  
>  
> 
> Jianguo
> 
>