[Insight-users] Question about itkBSplineDeformableTransform

[Luke Bloy]

Hi,

I'm using BSpliceDeformableTransform for a registration problem, using a 
variation of a meanSquaresImageToImage metric. I'd like to speed it up 
by making use of the fact that not all parameters are important for 
transforming each voxel location. I believe that 
itkMattesMutualInformationImageToImageMetric makes use of this to speed 
up the computation of the derivative etc,but  I can't quite figure out 
howto make it happen.

Ideally, given a voxel index, I'd like to be able to to determine which 
parameters affect it's transformation. I think i can get this info from the
GetJacobian 
<http://www.itk.org/Doxygen310/html/classitk_1_1BSplineDeformableTransform.html#56d6093265189be09c75e684069ce92c> 
(const InputPointType 
<http://www.itk.org/Doxygen310/html/classitk_1_1Point.html> &inputPoint, 
WeightsType <http://www.itk.org/Doxygen310/html/classitk_1_1Array.html> 
&weights, ParameterIndexArrayType 
<http://www.itk.org/Doxygen310/html/classitk_1_1Array.html> &indices) 
method, but I'm not sure what it returns in weighs or in indices.

Any help would be greatly appreciated.

Thanks,
Luke