Image Registration Method Displacement 1 Example: Composite transform order

Beginner Questions
1

Hello,
Regarding one of the examples on the SimpleITK documentation website: Image Registration Method Displacement 1 — SimpleITK 2.0rc2 documentation
In this example, an affine + displacement registration is done, but at the end, the composition transform is written as:
compositeTx = sitk.CompositeTransform([outTx1, displacementTx]), in which outTx1 is the affine transform.
As the sitk.CompositeTransform applies the first added transforms last, shouldn’t it be compositeTx = sitk.CompositeTransform([displacementTx, outTx1]) , to apply the affine first (given that we even initialised with the displacement registration with the affine by applying R.SetMovingInitialTransform(outTx1))?
Thank you in advance for your time and help.

2

Hello,

Please see the following documentation on how the transforms are applied to understand the ordering: Registration Overview — SimpleITK 2.0rc2 documentation

3

Thank you @blowekamp!

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