[Insight-developers] Derivatives of Recursive Gaussian dx scaling?

[Bradley Lowekamp]

Hello,

So I have been taking a very close look into the Derivative calculations of RecursiveGaussianImageFilter ( and related Laplacian, gradient, and Hessain ) along with GaussianDerivativeOperator (also related functions ). Why doesn't RecursiveGaussianImageFilter divide by spacing^order internally. Currently, the recursive Laplacian, Gradient and Hessian filters divide by it internally. The reason why I am asking is because currently the GaussianDerivativeOperator and related functions are missing this scaling factor. I am not sure if it should go into the Operator on in the functions, so I wanted to ask why this similar filter was implemented the way it was to assist with this design decision.


Also what is the future of the GaussianDerivativeOperator? Normally is would just be a matter of moving from review into Common/BasicFitlers, However with the ITKv4 it may make since to do a little consolidation as well. The GaussianDerivativeOperator and the GaussianOperator contain a good bit of redundant code, so the GaussianDerivativeOperator could replace the later with a different set of defaults.

Thanks,
Brad





========================================================
Bradley Lowekamp  
Lockheed Martin Contractor for
Office of High Performance Computing and Communications
National Library of Medicine 
blowekamp at mail.nih.gov


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