[Insight-users] Image to Image Metrics

[Luis Ibanez]

Hi Sven,

Thanks for clarifying your question.

Unfortunately you are facing here the essential difficulty of
image registration: There is no analytical way of finding
maxima or minima for the values of the ImageMetric.

We are therefore left with the option of running optimizers
that will explore the parametric space.

You may want to look at the Multi-Resolution examples in the
directory:


         Insight/Examples/Registration



     Regards,


        Luis


------------------
Fischer, Sven wrote:
> Hi Luis,
> 
> Thank you very much for your reply. I had a look at the example. But it's not exactly doing what I want. If I understand correct the Insight/Examples/Registration/MeanSquaresImageMetric1.cxx example calculates the metric values for different transformations. But I only need the maxima or minima. I can see approximately where they are when I look at the plot, but I can't find the exact position. 
> 
> I want to use multi-resolution. And it seems to me that the optimizer finds an optimum at coarser resolution that is away from the one I want to find. So I want to use several starting points when I go to higher resolution.
> 
> Sven
> 
> 
> -----Ursprüngliche Nachricht-----
> Von: Luis Ibanez [mailto:luis.ibanez at kitware.com] 
> Gesendet: Mittwoch, 23. Juli 2008 14:34
> An: Fischer, Sven
> Cc: insight-users at itk.org
> Betreff: Re: [Insight-users] Image to Image Metrics
> 
> 
> Hi Sven,
> 
> You may want to look at the example:
> 
>     Insight/Examples/Registration/MeanSquaresImageMetric1.cxx
> 
> This will plot the values of a metric for a range of the
> transform parameters (in this case, a simple translation).
> 
> You will find this example described in the ITK Software Guide
> 
> 
>       http://www.itk.org/ItkSoftwareGuide.pdf
> 
> 
> Note that for transforms with larger number of parameters
> it is harder to sample the cost function (image metric)...
> 
> 
> --
> 
> What Transform are you using ?
> 
> 
>      Please let us know,
> 
> 
>           Thanks
> 
> 
>               Luis
> 
> 
> --------------------
> Fischer, Sven wrote:
> 
>>Hi all,
>>
>>
>>  *I want to look at several maxima or minima of some Image to Image
>>  Metrics, like GradientDifferenceImageToImageMetric or
>>  MattesMutualInformationImageToImageMetric. Does someone know how I can
>>  get these values and the position? Thank you in advance.*
>>
>>
>>  *Regards,*
>>
>>
>>  *Sven*
>>
>>
>>------------------------------------------------------------------------
>>
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> 
>