[Insight-users] boundary of image

[Luis Ibanez]

Hi Chen,

The ITK implementation of morphology operations
also decompose the processing of the boundary
regions. This is done by the SmartNeighborhood
iterator.

So, the difference in preformance is not due to
boundary processing.



About your speed comparison:

1) In what platform are you compiling ITK ?

2) Did you enable the "Release" option in
   CMake when configuring ITK ?

   Enabling "Release" will add the flags for
   code optimization, given that most of ITK
   is templated code, there is a dramatic speed
   difference between code compiled for debug
   and code compiled for release.



Regards,


  Luis


-----------------------

Chen Fu wrote:
> Hi!
> I recently compare the morphology operation in vtk,
> itk and matlab. To my surprise, vtk and itk is much
> slower than matlab. 
> I believe the problem is the boundary processing. In
> vtk and itk code, every pixel must take 8 compares to
> confirm whether it is inside the image boundary. But
> in matlab, the boundary is preprocessed by extending
> the size of image, so get rid of such compares. I will
> try to do some modify of itk code to enhance its
> performance, but i am not very clearly how to do
> extend the image in itk's pipeline architecture. 
> Maybe somebody can give me some hints?
> 
> 
> =====
> Remote Scensing Satellite Ground Station
> Chinese Academy of Science
>