Install & Compatibility
Where this runs
tested against v5.4.6 · pip install
no network on importno background threads
Install × environment matrix
Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux
muslpy 3.10–3.95 runs
build_error
glibcpy 3.10–3.95 runs
installs and imports cleanly · install 16.9s · import 0.546s · 1433.6MB
1434MB installed
● package 1434MB
Code
Verified usage
Verified import paths — ran on the pinned version, not inferred.
itk
✓ import itk
✗ import itkRegistration
All modules are accessed via the 'itk' package.
Basic affine registration of 2D images using MeanSquares metric.
import itk
# Define image types
PixelType = itk.ctype('float')
FixedDimension = 2
MovingDimension = 2
FixedImageType = itk.Image[PixelType, FixedDimension]
MovingImageType = itk.Image[PixelType, MovingDimension]
# Read images
fixed_image = itk.imread('fixed_image.nii', PixelType)
moving_image = itk.imread('moving_image.nii', PixelType)
# Set up registration
RegistrationType = itk.ImageRegistrationMethod[FixedImageType, MovingImageType]
registration = RegistrationType.New()
registration.SetFixedImage(fixed_image)
registration.SetMovingImage(moving_image)
# Set metric (e.g., MeanSquares)
metric = itk.MeanSquaresImageToImageMetric[FixedImageType, MovingImageType].New()
registration.SetMetric(metric)
# Set transform (e.g., Affine)
transform = itk.AffineTransform[itk.D, 2].New()
registration.SetInitialTransform(transform)
# Set optimizer
optimizer = itk.RegularStepGradientDescentOptimizerv4.New()
registration.SetOptimizer(optimizer)
# Set interpolator
interpolator = itk.LinearInterpolateImageFunction[MovingImageType, itk.D].New()
registration.SetInterpolator(interpolator)
# Run registration
registration.Update()
# Get result
result = registration.GetOutput()
itk.imwrite(result, 'registered_image.nii')
Errors
Common errors & fixes
NameError: name 'FixedImageType' is not defined
Forgot to define the image type before using it in registration templates.
fixDefine FixedImageType = itk.Image[itk.F, 2] (or itk.D) before creating the registration object.
RuntimeError: Exception thrown in SimpleITK ImageRegistrationMethod_New
Mismatch between template types and actual image dimensions or pixel type.
fixEnsure FixedImageType and MovingImageType dimensions and pixel types match your images.
TypeError: in method 'New', argument 1 of type 'itkImageToImageMetricv4...'
Incorrect metric type template parameters.
fixUse metric = itk.MeanSquaresImageToImageMetric[FixedImageType, MovingImageType].New() with matching types.
Upgrade
Version history
5.4.6latest on PyPI · released Apr 23, 2026
Audit
Dependencies
itkrequiredCore ITK package is required.