Continuing the discussion from Creating a displacement field image from a numpy array:
Hello!
I am trying to warp an image. The image is built from an array, and I would like to build the displacement field from another array as well.
(This post is very similar. This and this may be related). The difference is that I am trying to do this (1) without reading files and (2) setting each voxel (pixel) value with for loops (something like ImageIterator), but using pure arrays. My hair is getting loose 
.
import numpy as np
import itk
img_shape = (5, 101, 101)
fixed_image = itk.image_from_array(
np.zeros(img_shape).astype(np.float32))
array_from_fixed_image = itk.array_from_image(fixed_image)
VoxelType = itk.F
ImageDimension = len(img_shape)
ImageType = itk.Image[VoxelType, ImageDimension]
VectorVoxelType = itk.F
VectorDimension = 3
VectorTypeDim = itk.Vector[VectorVoxelType, VectorDimension]
VectorImageType = itk.Image[VectorTypeDim, ImageDimension]
DisplacementField = itk.image_from_array(
np.ones((3, *array_from_fixed_image.shape),
dtype=np.float32),
is_vector=True)
interpolator = itk.LinearInterpolateImageFunction[
ImageType, itk.D].New()
# This statement failed
warpFilter = itk.WarpImageFilter[
ImageType, ImageType, itk.Image[itk.F,4]].New(
Interpolator=interpolator,
OutputSpacing=fixed_image.GetSpacing(),
OutputOrigin=fixed_image.GetOrigin(),
DisplacementField=DisplacementField,
Input=fixed_image)
moving_image = warpFilter.GetOutput()
The error that I get is:
>>>
Traceback (most recent call last):
File "/home/edgar/.local/lib/python3.10/site-packages/itk/support/template_class.py", line 525, in __getitem__
this_item = self.__template__[key]
KeyError: (<class 'itk.itkImagePython.itkImageF3'>, <class 'itk.itkImagePython.itkImageF3'>, <class 'itk.itkImagePython.itkImageF4'>)
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "<string>", line 17, in __PYTHON_EL_eval
File "<string>", line 26, in <module>
File "/home/edgar/.local/lib/python3.10/site-packages/itk/support/template_class.py", line 529, in __getitem__
raise itk.TemplateTypeError(self, key)
itk.support.extras.TemplateTypeError: itk.WarpImageFilter is not wrapped for input type `itk.Image[itk.F,3], itk.Image[itk.F,3], itk.Image[itk.F,4]`.
To limit the size of the package, only a limited number of
types are available in ITK Python. To print the supported
types, run the following command in your python environment:
itk.WarpImageFilter.GetTypes()
Possible solutions:
* If you are an application user:
** Convert your input image into a supported format (see below).
** Contact developer to report the issue.
* If you are an application developer, force input images to be
loaded in a supported pixel type.
e.g.: instance = itk.WarpImageFilter[itk.Image[itk.SS,2], itk.Image[itk.SS,2], itk.Image[itk.Vector[itk.F,2],2]].New(my_input)
* (Advanced) If you are an application developer, build ITK Python yourself and
turned to `ON` the corresponding CMake option to wrap the pixel type or image
dimension you need. When configuring ITK with CMake, you can set
`ITK_WRAP_${type}` (replace ${type} with appropriate pixel type such as
`double`). If you need to support images with 4 or 5 dimensions, you can add
these dimensions to the list of dimensions in the CMake variable
`ITK_WRAP_IMAGE_DIMS`.
Supported input types:
itk.Image[itk.SS,2]
itk.Image[itk.UC,2]
itk.Image[itk.US,2]
itk.Image[itk.F,2]
itk.Image[itk.D,2]
itk.Image[itk.SS,3]
itk.Image[itk.UC,3]
itk.Image[itk.US,3]
itk.Image[itk.F,3]
itk.Image[itk.D,3]
itk.Image[itk.SS,4]
itk.Image[itk.UC,4]
itk.Image[itk.US,4]
itk.Image[itk.F,4]
itk.Image[itk.D,4]