Filter does not support casting from casting vector of 8-bit unsigned integer to 32-bit float

[francisr]

Hi,

I'm trying to run the affine registration example: https://simpleelastix.readthedocs.io/AffineRegistration.html I've downloaded the brain images from the page (png format), but when I try to run the example code, I get:

  File "./register.py", line 9, in <module>
    elastixImageFilter.Execute()
  File "/home/francisr/registration/venv/lib/python3.5/site-packages/SimpleITK-1.2.0rc2.dev1162+g2a79d-py3.5-linux-x86_64.egg/SimpleITK/SimpleITK.py", line 10996, in Execute
    return _SimpleITK.ElastixImageFilter_Execute(self)
RuntimeError: Exception thrown in SimpleITK ElastixImageFilter_Execute: /home/francisr/registration/SimpleElastix/Code/BasicFilters/src/sitkCastImageFilter.cxx:99:
sitk::ERROR: Filter does not support casting from casting vector of 8-bit unsigned integer to 32-bit float

[kaspermarstal]

Hi @francisr. You have to cast to a vector of 32-bit float (if that's what you intend to do) or use VectorIndexSelectionCastImageFilter() and choose which component of the vector image you want to extract and cast.

[JLrumberger]

Same problem, I have two images IF_itk_x4 = sitk.GetImageFromArray(IF_np_x4_norm, sitk.sitkFloat32) HE_itk_x4 = sitk.GetImageFromArray(HE_np_x4_norm, sitk.sitkFloat32)

and want to do affine registration:

elastixImageFilter = sitk.ElastixImageFilter() elastixImageFilter.SetFixedImage(HE_itk_x4) elastixImageFilter.SetMovingImage(IF_itk_x4) elastixImageFilter.SetParameterMap(sitk.GetDefaultParameterMap("affine")) elastixImageFilter.Execute()

and get the error:

---

RuntimeError Traceback (most recent call last) in 3 elastixImageFilter.SetMovingImage(IF_itk_x4) 4 elastixImageFilter.SetParameterMap(sitk.GetDefaultParameterMap("affine")) ----> 5 elastixImageFilter.Execute()

C:\ProgramData\Anaconda3\lib\site-packages\simpleitk-2.0.0+ggitdir.notfound-py3.8-win-amd64.egg\SimpleITK\SimpleITK.py in Execute(self) 11128 def Execute(self): 11129 """Execute(ElastixImageFilter self) -> Image""" 11130 return _SimpleITK.ElastixImageFilter_Execute(self) 11131 11132

RuntimeError: Exception thrown in SimpleITK ElastixImageFilter_Execute: C:\Users\Lorenz\Documents\libraries\SimpleElastix\Code\BasicFilters\src\sitkCastImageFilter.cxx:101: sitk::ERROR: Filter does not support casting from casting vector of 32-bit float to 32-bit float

I was able to solve this with your suggestion: selectCastFilter = sitk.VectorIndexSelectionCastImageFilter() selectCastFilter .SetIndex(0) selectCastFilter .SetOutputPixelType(sitk.sitkFloat32) HE_res = selectCastFilter .Execute(HE_itk_x4) IF_res = selectCastFilter .Execute(IF_itk_x4)