### Author:  [@Soren\_Christensen](https://discourse.itk.org/u/Soren_Christensen)
#### Post date: [March 22, 2021, 12:30pm UTC](https://discourse.itk.org/t/keyerror-itksmoothing-when-initializing-regularstepgradientdescentoptimizerv4/3973/1 "2021-03-22T12:30:17Z")
Hi,
I have a fresh pip install of 5.1.1 and get this error when creating an ImageRegistrationMethodv4
```auto
object:
registration = itk.ImageRegistrationMethodv4.REGv4F3F3.New(FixedImage=fixed,
MovingImage=moving,
Metric=metric,
Optimizer=optimizer,
InitialTransform=identityTransform)
```
My metric is using raycastinterpolater as interpolater I saw another post from last year with the same error message for the SiddonJacobRayCastInterpolateImageFunction filter but there were no replies to that post.
Any ideas appreciated!
Thanks!
Soren
```nohighlight
Traceback (most recent call last):
File "/home/sorenc/CODE/reg/reg_sandbox.py", line 45, in
register(itk_image,dsa_itk_img,beam_location.tolist())
File "/register.py", line 14, in register
optimizer = itk.RegularStepGradientDescentOptimizerv4.New(
File "/home/sorenc/.virtualenvs/sitk/lib/python3.6/site-packages/itkLazy.py", line 52, in __getattribute__
itkBase.LoadModule(module, namespace)
File "/home/sorenc/.virtualenvs/sitk/lib/python3.6/site-packages/itkBase.py", line 91, in LoadModule
LoadModule(dep, namespace)
File "/home/sorenc/.virtualenvs/sitk/lib/python3.6/site-packages/itkBase.py", line 91, in LoadModule
LoadModule(dep, namespace)
File "/home/sorenc/.virtualenvs/sitk/lib/python3.6/site-packages/itkBase.py", line 87, in LoadModule
data = module_data[name]
KeyError: 'ITKSmoothing'
```
---
### Author:  [@dzenanz](https://discourse.itk.org/u/dzenanz)
#### Post date: [March 22, 2021, 7:12pm UTC](https://discourse.itk.org/t/keyerror-itksmoothing-when-initializing-regularstepgradientdescentoptimizerv4/3973/2 "2021-03-22T19:12:14Z")
Does the error go away if you import ITK like this:
```auto
# disable lazy loading first and then import itk
import itkConfig
itkConfig.LazyLoading = False
import itk
```
---
### Author:  [@Soren\_Christensen](https://discourse.itk.org/u/Soren_Christensen)
#### Post date: [March 22, 2021, 7:47pm UTC](https://discourse.itk.org/t/keyerror-itksmoothing-when-initializing-regularstepgradientdescentoptimizerv4/3973/3 "2021-03-22T19:47:21Z")
Thank you Dzenanz!
Yes, that takes care of it.
Soren
---
### Author:  [@matt.mccormick](https://discourse.itk.org/u/matt.mccormick)
#### Post date: [March 23, 2021, 11:56pm UTC](https://discourse.itk.org/t/keyerror-itksmoothing-when-initializing-regularstepgradientdescentoptimizerv4/3973/4 "2021-03-23T23:56:13Z")
> [@Soren\_Christensen](#):
>
> ```auto
> registration = itk.ImageRegistrationMethodv4.REGv4F3F3.New(FixedImage=fixed,
> MovingImage=moving,
> Metric=metric,
> Optimizer=optimizer,
> InitialTransform=identityTransform)
>
> ```
We can avoid the error and automatically get the correct filter type by omitting `.REGv4F3F3` (tested with `itk-5.2rc3`):
```auto
registration = itk.ImageRegistrationMethodv4.New(fixed_image=fixed_image,
moving_image=moving_image,
metric=metric,
optimizer=optimizer,
initial_transform=identityTransform)
```
A full example with the modern, Pythonic `itk` style:
>
---
### Author:  [@Soren\_Christensen](https://discourse.itk.org/u/Soren_Christensen)
#### Post date: [April 2, 2021, 3:07pm UTC](https://discourse.itk.org/t/keyerror-itksmoothing-when-initializing-regularstepgradientdescentoptimizerv4/3973/6 "2021-04-02T15:07:34Z")
Thanks!
I upgraded to 5.2 but I seem to still have issues with the types:
itk. **version**
‘5.2.0’
fixed\_image
\ \>
moving\_image
\ \>
registration = itk.ImageRegistrationMethodv4.New(fixed\_image=fixed\_image,
moving\_image=moving\_image,)
TypeError: in method ‘itkImageRegistrationMethodv4REGv4F2F2\_SetFixedImage’, argument 2 of type ‘itkImageF2 const \*’
Additional information:
Wrong number or type of arguments for overloaded function ‘ **itkImageRegistrationMethodv4REGv4F2F2\_SetFixedImage** ’.
Possible C/C++ prototypes are:
itkImageRegistrationMethodv4REGv4F2F2::SetFixedImage(itkImageF2 const \*)
itkImageRegistrationMethodv4REGv4F2F2::SetFixedImage(unsigned long,itkImageF2 const \*)
---
### Author:  [@matt.mccormick](https://discourse.itk.org/u/matt.mccormick)
#### Post date: [April 7, 2021, 1:54am UTC](https://discourse.itk.org/t/keyerror-itksmoothing-when-initializing-regularstepgradientdescentoptimizerv4/3973/7 "2021-04-07T01:54:56Z")
What code was used?
> **itkImageF3**
> itkImageF2
it appears that we are trying to use 3D images in a 2D image filter.