[Elastix Parameters --> ITK Transforms] Provide function to convert Elastix's TransformParameter.txt to ITK transforms

Context

• 3D Visualization software like 3D Slicer provide a larger number of visualization modules for different purposes.
• One of the modules, the Transform module allows loading of .tfm files. These files can be created by using for e.g. sitk.WriteTransform(sitk.BSplineTransform(3), 'BSpline.tfm'). This Transform module is quite handy as it allows for easy visualization of the deformed grids of BSpline.

Is there a roadmap to include these kind of Elastix -> ITK Transform helper functions in ITKElastix?

• Example 1: Convert Affine + BSpline into a Composite Transform

[N-Dekker]

@thewtex

Reference: https://github.com/SuperElastix/elastix/tree/develop/Testing/Data/Translation(1%2C-2)

Explanation: The current “develop” branch of elastix supports elastix transform parameter files that link to an ITK generated HDF5 or TFM file. For example, this is a supported elastix transform parameters file: https://github.com/SuperElastix/elastix/blob/develop/Testing/Data/Translation(1%2C-2)/TransformParameters-link-to-ITK-tfm-file.txt In this case, it links to the following ITK transform file: https://github.com/SuperElastix/elastix/blob/develop/Testing/Data/Translation(1%2C-2)/ITK-Transform.tfm

(Such an elastix transform parameters file may be used as input for both Elastix (as initial transform parameter file) and Transformix.)

At the moment, four ITK transform types are actively tested as input to elastix: Translation, Affine, Euler, and Similarity. I’m still busy preparing to add tests for BSpline.

[dzenanz]

Writing an ITK transform into .tfm file should be no different from writing into .h5.