[Insight-users] periodic boundary conditions and recursive gaussian filter

[Luis Ibanez]

Hi Jan,



    Yes, It is possible   :-)


    But, It is not implemented.



This is a non-trivial task. In order to implement periodic
boundary conditions you will have to get familiar with the
computation of the coefficients for the IIR filters that are
used in the Recursive Gaussian Filter.

Note that it is not as simple as enlarging the array and
tricking the filter by suffing the replicated values, because
this filter is not using a finite support for a convolution
kernel. This filter actually approximates an infinite support
kernel.


This can well be a semester project for a student
in a signal processing class.


---

About the Doxygen question, what happens is the our use of
Generic Programming makes harder for Doxygen to figure out
all the inheritance relationships.


One way of getting a full list of derived classes is by using
SourceNavigator

          http://sourcenav.sourceforge.net/

This nice application builds a full database of a software
project and helps you browse the code by finding all the
variables, types, functions, classes and header relationships.




     Regards,



       Luis




-------------------
Jan Ehrhardt wrote:

> Hi,
> 
> is it possible to get periodic boundary conditions for the 
> RecursiveGaussianImageFilter (or more general for
> RecursiveSeparableImageFilters) ?
> Specifically, I want to calculate the gradient (with a gaussian 
> derivative) of an image with periodic boundary conditions in z-direction 
> and neumann conditions in x/y-direction. In the next step, I want to 
> apply gaussian smoothing to a N-dimensional vector-field with periodic 
> boundary conditions in z-direction and neumann conditions in x/y-direction.
> 
> One idea is to reimplement RecursiveSeparableImageFilters and to enlarge 
> the array given to FilterDataArray (..). But how many values I have to add?
> 
> Another small problem: the doxygen documentation don't lists all  
> subclasses in the inheritance diagramm. How can I get a list of _all_ 
> subclasses e.g. of the ImageToImageFilter ?
> 
> Thanks,
> 
> Jan
> 
> 
> 
> 
> _______________________________________________
> Insight-users mailing list
> Insight-users at itk.org
> http://www.itk.org/mailman/listinfo/insight-users
> 
>