Pythonic interface to ITK filters

A new patch is available to add a more Python interface to ITK filters in ITK 5:

This auto-generates a procedural, snake_case interface to ITK filters, i.e. anything that inherits from itk.ProcessObject. Instead of the Object-oriented interface,

median_filter = itk.MedianImageFilter[ImageType, ImageType].New()
result = median_filter.GetOutput()

we can just call

result = itk.median_image_filter(input_image, radius=radius)

This leverages the work by Gaetan Lehmann many years ago in the Python wrapping, which was recently updated and improve by @fbudin. Here the filter is implicitly updated and its output is returned if there is a single output, or the indexed outputs are returned as a tuple if there are multiple. The type of the filter is determined by the input_image type. Parameters that could be set on the object with SetParameterName can be specified with keyword arguments also in snake case, e.g. parameter_name.

@glemaitre @cdeepakroy


This is actually looking great and what I had in mind at that time.
It seems that you are in SciPy so you might use the feedback of some Python user :slight_smile:

@glemaitre excellent. Yes, I am at the SciPy conference, and I will see if I can get some feedback.

If anyone in the community is at SciPy, I would be happy to meet with you. :handshake:

How does this relate to SimpleITK’s python interface. I have been using that to avoid writing C++ code. Is this the supported interface going forward?

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We continue to work on and support SimpleITK. I’d suggest using which ever interface suits your needs better.

Okay, I’ll ask the question slightly differently then, what are the major differences between SimpleITK and ITK’s pythonic interfaces?

  • For the procedural functions, SimpleITK has custom function names created per image filter that are CamelCase, e.g. sitk.Median versus the snake_case version of the corresponding ITK filter, e.g. itk.median_image_filter
  • Parameters for SimpleITK are often custom positional or camelCase, where parameters for ITK are the snake_case keyword arguments that correspond to the SetParameterName methods.
  • SimpleITK supports image filters. ITK’s Pythonic functions are anything that inherits from itk.ProjectObject, i.e. mesh filters, point set filters, path filters, image filters …
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