[Insight-users] gradientRecursiveGaussianImageFilter

[Martin Urschler]

hello all,

I was looking at the GradientRecursiveGaussianImageFilter to find the 
reason why the standard rigid registration allocates lots of memory. I 
get an out of memory exception when registering two 512x512x231 images 
(I have to say that I'm holding some more images in memory, however the 
registration method seems to allocate more than 1GB RAM for gradient 
calculation, which seems to me like being too much).
Could anyone explain to me, what the mini pipeline consisting of 
NrDimensions ZeroOrder gauss images and one FirstOrder gauss image 
(derivative) is used for? Naively I would say one only needs the 
derivative filter for each dimension.

thanks,
Martin