[question] how to replicate a ridig registration done with ANTs / niftyreg

[neuronflow]

I am exploring whether we can replace an ANTs / niftyreg registration step in our pipelines with sitk. Which parameters would I need to replicate the functionality of:

reg_aladin \
    -rigOnly \
    -ref $fixed \
    -flo $moving \
    -res $transformed \
    -aff $matrix \
    -pad 0

ANTs we call with the following parameters:

if transformationalgorithm == "rigid":
        # rigid ants_transformation
        transform_rigid = "-t rigid[0.1]"
        metric_rigid = "-m Mattes[" + fixed_image + "," + moving_image + ", 1, 32, Regular, 0.5]"
        convergence_rigid = "-c [1000x500x250, 1e-6, 10]"
        smoothing_sigmas_rigid = "-s 3x2x1vox"
        shrink_factors_rigid = "-f 8x4x2"

Thanks for your help!