I have a vtkImageData called img that I want to use the vtkImageReslice algorithm on.
I want to reslice this image data to create a subimage that has its voxels aligned to a different coordinate system.
To do this i am using the following code:
reslice = vtk.vtkImageReslice()
reslice.SetInterpolationModeToLinear()
reslice.SetResliceAxes(get_subimg_rotation_matrix4x4())
reslice.SetOutputOrigin(get_subimg_origin())
dims = get_subimg_dimensions()
reslice.SetOutputExtent(0, dims[0]-1, 0, dims[1]-1, 0, dims[2]-1)
reslice.SetOutputSpacing(get_subimg_spacing())
transform = vtk.vtkTransform()
transform .SetMatrix(get_subimg_rotation_matrix4x4())
reslice.SetResliceTransform(transform.GetInverse())
reslice.SetInputData(img)
reslice.Update()
subimg = reslice.GetOutput()
Here, get_subimg_rotation_matrix4x4() just returns a rotation + translation matrix that defines the reslice axes, like:
[
[cos(theta), -sin(theta), 0.0, origin_x],
[sin(theta), cos(theta), 0.0, origin_y],
[0.0, 0.0, 1.0, origin_z],
[0.0, 0.0, 0.0, 1.0]
]
I’m confused because the subimg output does not have a direction matrix aligned with the ResliceAxes. And so when I visualize these images, they look as if their axes are aligned, even though ResliceAxes have been set to be rotated.
Can anyone post a working example of what I’m trying to accomplish?