[Insight-users] Question about SetNormalizeAcrossScale() in RecursiveGaussianImageFilter

[Martin T King]

Hi,

I have a question about SetNormalizeAcrossScale() in 
itk::RecursiveGaussianImageFilter.  According to the doxygen generated document 
of itkRecursiveGaussianImageFilter.h, setting SetNormalizeAcrossScale to ON 
would prevent larger sigmas from fading the image 1/[sqrt(2*PI)], whereas, 
setting this to OFF would preserve the constant integral of image intensity 
1/[sigma*sqrt(2*PI)].

However, according to the itkSoftwareGuide.pdf for ITK version 2.4 (November 
21, 2005), enabling this option to ON (as recommended for scale-space analysis) 
would preserve the maximum value of the input.  This normalization would be 
represented by 1/[sigma*sqrt(2*PI)].  These statements sound contradictory, as 
the ON normalization in the software guide seems to correspond to the OFF 
normalization in the doxygen generated document.

Could you clarify?

Thanks,
Martin