[Insight-users] Scales Type parameters

[Jordi Romagós Figueras]

Hello everybody,

First of all I apologize for my English, this is my first post in Internet.

I’m using itk for mammography images registering , and I’m trying the
different kinds of Optimizers, Metrics and Transformations.

Now, all works with example images (for example
BrainProtonDensitySliceBorder20.png with rotations and translations). But
with mammography images doesn’t work, I discovered is due for Scales Type
parameters of Transformer that I put on Optimizer (Regular Gradient) or in
Metric (Normalized Mutual Information).

I found one example in one PowerPoint put 1.0 for angle parameters and
1/1000 in the others parameters, this works fine with the example images
like BrainProtonDensitySliceBorder20. Then, after trying various values for
mammographies images I found works “well” with 1/1000000 for non angle
parameters. My question is about Scales Type Parameters, I don’t understand
what relation must have.

I use Affine Transform and Rigid (Centered and not Centered) Transform.

Thanks, Jordi.

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