[Insight-users] Mutual Information Error

[Luis Ibanez]

Hi Jordan,


This message is typically produced when the Transform is such that
the Moving image is mapped outside the extent of the Fixed image.

The lack of overlap between the Fixed image and the mapped Moving
image makes impossible to compute the Metric, and therefore an
Exception is thrown.


Please post to the list the characteristics of your two images.

      - Number of pixels along each dimension
      - Pixel spacing
      - Origin



You can get spacing and origing very easily by just invoking


      fixedImageReader->GetOutput()->Print( std::cout );
      movingImageReader->GetOutput()->Print( std::cout );

    [after having invoked the Update() methods of the readers]




It is very likely that the origin of your images is such that
initializing the Transform as an Identity is not appropriate.



In that case, you may want to use the Transform Initializer, as
illustrated in the ITK Software Guide


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


Chapter 8,



    Regards,



        Luis



--------------------------
Jordan Soet wrote:

> I'm working the mutual information metric on 3D ultrasound images, and 
> as a quick test I tried using ImageRegistration11 on it with the 
> dimension changed to 3 (and the parameters for the transform changed as 
> well). However, when I try and run it I get the following error:
> 
> $ ./ImageRegistration11.exe I0000005.hdr I0000006.hdr
> ExceptionObject caught !
> 
> itk::ExceptionObject (0xa05c370)
> Location: "Unknown"
> File: 
> /home/Jordan/InsightToolkit-2.0.1/Code/Algorithms/itkMattesMutualInformationImageToImageMetric.txx 
> 
> Line: 623
> Description: itk::ERROR: 
> MattesMutualInformationImageToImageMetric(0xa0528a0): Too many samples 
> map outside moving image buffer: 0 / 10000
> 
> I'd guess that it's something to do with the regions, however, the 
> images are the same size, and I didn't change anything from the example, 
> so I don't know what the matter is... Does anyone know what the problem is?
> 
> 
> Thanks,
> 
> Jordan
> _______________________________________________
> Insight-users mailing list
> Insight-users at itk.org
> http://www.itk.org/mailman/listinfo/insight-users
> 
>