[Insight-users] Re: Registration Slice to Volume

[Luis Ibanez]

Hi Albert,

I second Rupert's opinion here.

It would be more natural to use the Slice as the fixed image.
Even though that may sound counter-intuitive.

You may want to read the introduction section of the
"Image Registration" chapter in the ITK Software Guide:

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


where this issues are discussed.


    Regards,


       Luis


-----------------------
Rupert Brooks wrote:
> Hi Albert,
> 
> To help a bit more i think we would need to know more specifically
> what problems you have with the metric.
> 
> I'd say that the slice has to be the fixed image, otherwise there will
> be problems computing the derivative in the direction normal to the
> slice.  I'd also recommend using a different interpolator.  The
> Nearest neighbor can pose problems for registration as it leads to a
> very rough cost function.  A linear interpolator is also far from
> ideal, but usually manages to work anyway.
> 
> Rupert B.   
>     
> 
>> Jul 2, 2007 (yesterday)
>> Registration Slice to Volume
>> from ITK by Albert Gubern
>> Hi,
>>
>> I'm trying to do Registration slice to volume. Firstly and to make it
> 
> as easy as >possible, I extract a slice (fixedImage) of the volume 3d
> (movingImage). I want the >registration say me the z of the slice into
> the volum 3D .
> 
>>
>> Slice is casted to volume of only one slice to have two image with
> 
> the same >dimension.
> 
>>
>> typedef itk::Image<unsigned char,2> ImageType;
>> typedef itk::Image<float,3> FixedImageType;
>> typedef itk::CastImageFilter< ImageType, FixedImageType > 
>> CastFilterType2D;
>> caster2D->SetInput( filter->GetOutput() ); //filter->GetOutput() is
> 
> the slice 2D
> 
>>
>> Moreover, I've tried it with a TranslationTransform,
>> MeanSquaresImageToImageMetric and
>> NearestNeighborInterpolateImageFunction but I have problems with
> 
> metric.
> 
>>
>> I think that this is the way to make it, but I am not sure if I have
> 
> to make a >different cast or if I have to choose another metric.
> 
>>
>> I'll thank if someone can help me, say me where can be the mistake or
> 
> which >metric and interpolator I have to use.
> 
>>
>> Cheers
>>
>> -- 
>> Albert
> 
>