[Insight-users] Determining itk::RegularStepGradientDescentOptimizer->SetScales()

[Jan Schreiber]

Hello ITK-Users, 

I am performing registration on 2D x-ray images, using
MattesMutualInformation, Similarity2DTransform, AffineTransform and
RegularStepGradientDescentOptimizer. 

Does anyone know a good way to determine the values for the SetScales()
function?
Is there a methodical way to compute these values or to estimate them
from samples?

I played around with some values I took from the examples with the
result that it works for some images but not for others (e.g. different
image size)

Thanks in advance, 
Jan