[Insight-users] Gaussian of masked images

[Luis Ibanez]

Hi Kai,

Do you want to exclude some pixels from being input to the Gaussian ?

or to you want to exclude some pixels from receiving the result of
the Gaussian computation ?

The first one may not be a very formal operation...

What is the purpose of excluding those pixels ?


Please let us know,


    Thanks


     Luis


-------------
Kai Li wrote:

> Hi Luis,
>    Thanks for your information, but what I exactly want is a filter for
> "masked" image. This may looks weird you. What I meant is that some pixels
> in a, say, grey image do not take part in the computation of the Gaussian.
> 
> Thanks,
> Kai
> 
> On Fri, 2 Jul 2004, Luis Ibanez wrote:
> 
> 
>>Hi Kai,
>>
>>If you are using large Gaussians you will find more
>>efficient to use the LaplacianRecursiveGaussian filter
>>
>>http://www.itk.org/Insight/Doxygen/html/classitk_1_1LaplacianRecursiveGaussianImageFilter.html
>>
>>This filter internally uses IIR filters and therefore
>>its computation time is independent of the size of your
>>sigma.
>>
>>You will find examples on the use of this filter in the
>>files
>>
>>
>>   Insight/Examples/Filtering/
>>        LaplacianRecursiveGaussianImageFilter1.cxx
>>        LaplacianRecursiveGaussianImageFilter2.cxx
>>        ScaleSpaceGenerator2D.cxx
>>
>>
>>
>>
>>   Regards,
>>
>>
>>     Luis
>>
>>
>>
>>-------------
>>Kai Li wrote:
>>
>>
>>>Hi,
>>>  I'm in a situation where Laplacian of Gaussian(LoG) of masked images has
>>>to be computed. I'm wondering if ITK has already provided something to
>>>archieve this.
>>>
>>>  The method that I can come up with at this point is to use a
>>>Difference-Of-Gaussian operator that can compute the Gaussian derivatives
>>>for each pixel and mask the kernel of the operator dynamically for each pixel.
>>>This method seems OK but not efficient for the computation in large
>>>scale(sigma).
>>>
>>>  Any suggestion is highly appreciated.
>>>
>>>Kai
>>>_______________________________________________
>>>Insight-users mailing list
>>>Insight-users at itk.org
>>>http://www.itk.org/mailman/listinfo/insight-users
>>>
>>
>>
>>
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