namespace itk
{
template< typename T >
void
ViewImage( const T* img,
const std::string& win_title,
size_t win_x,
size_t win_y )
{
using ConnectorType = itk::ImageToVTKImageFilter< T >;
auto connector = ConnectorType::New();
connector->SetInput(img);
connector->Update();
connector->UpdateLargestPossibleRegion();
// Setup renderers
vtkSmartPointer< vtkRenderer > renderer = vtkSmartPointer< vtkRenderer >::New();
// Setup render window
vtkSmartPointer< vtkRenderWindow > renderWindow = vtkSmartPointer< vtkRenderWindow >::New();
renderWindow->SetWindowName(win_title.c_str());
renderWindow->SetSize(win_x, win_y);
renderWindow->AddRenderer(renderer);
// Setup render window interactor
vtkSmartPointer< vtkRenderWindowInteractor > renderWindowInteractor =
vtkSmartPointer< vtkRenderWindowInteractor >::New();
vtkSmartPointer< vtkInteractorStyleRubberBand3D > style =
vtkSmartPointer< vtkInteractorStyleRubberBand3D >::New();
renderWindowInteractor->SetInteractorStyle(style);
// Render and start interaction
renderWindowInteractor->SetRenderWindow(renderWindow);
// Prepare for slices.
using FilterType = itk::StatisticsImageFilter< T >;
auto filter = FilterType::New();
filter->SetInput(img);
filter->Update();
filter->UpdateLargestPossibleRegion();
double min_intensity = filter->GetMinimum();
double max_intensity = filter->GetMaximum();
double window = max_intensity - min_intensity;
double level = min_intensity + window / 2;
/** SLICES */
FixedArray< vtkSmartPointer< vtkImagePlaneWidget >, 3 > slice_planes;
for ( unsigned i = 0; i < 3; ++i )
{
slice_planes[i] = vtkSmartPointer< vtkImagePlaneWidget >::New();
slice_planes[i]->SetResliceInterpolateToCubic();
slice_planes[i]->DisplayTextOn();
slice_planes[i]->SetInteractor(renderWindowInteractor);
slice_planes[i]->PlaceWidget();
slice_planes[i]->SetSliceIndex(0);
slice_planes[i]->SetMarginSizeX(0);
slice_planes[i]->SetMarginSizeY(0);
slice_planes[i]->SetRightButtonAction(
vtkImagePlaneWidget::VTK_SLICE_MOTION_ACTION);
slice_planes[i]->SetMiddleButtonAction(
vtkImagePlaneWidget::VTK_WINDOW_LEVEL_ACTION);
slice_planes[i]->TextureInterpolateOff();
slice_planes[i]->SetInputData(connector->GetOutput());
slice_planes[i]->SetPlaneOrientation(i);
slice_planes[i]->UpdatePlacement();
slice_planes[i]->SetWindowLevel(window, level);
slice_planes[i]->On();
}
// Flip camera because VTK-ITK different corner for origin.
double pos[3];
double vup[3];
vtkCamera *cam = renderer->GetActiveCamera();
cam->GetPosition(pos);
cam->GetViewUp(vup);
for ( unsigned int i = 0; i < 3; ++i )
{
pos[i] = -pos[i];
vup[i] = -vup[i];
}
cam->SetPosition(pos);
cam->SetViewUp(vup);
renderer->ResetCamera();
renderWindowInteractor->Initialize();
renderWindowInteractor->Start();
}
}// namespace itk
#endif
```
And the `.wrap` file:
```auto
itk_wrap_class("itk::ViewImage")
UNIQUE(types "${WRAP_ITK_SCALAR}")
UNIQUE(dims "2;3")
foreach(d ${dims})
foreach(t ${types})
itk_wrap_template("${ITKM_I${t}${d}}" "${ITKT_I${t}${d}}")
endforeach()
endforeach()
itk_end_wrap_class()
```
---
### Author:  [@matt.mccormick](https://discourse.itk.org/u/matt.mccormick)
#### Post date: [May 1, 2018, 11:54pm UTC](https://discourse.itk.org/t/python-wrapping-error-cannot-define-or-redeclare-x-here-because-namespace-wrappers-does-not-enclose-namespace-itk/886/2 "2018-05-01T23:54:58Z")
Hi Pablo,
To use the existing wrapping macros, you may need to put the function in a class.
HTH,
Matt
---
### Author:  [@phcerdan](https://discourse.itk.org/u/phcerdan)
#### Post date: [May 2, 2018, 12:54am UTC](https://discourse.itk.org/t/python-wrapping-error-cannot-define-or-redeclare-x-here-because-namespace-wrappers-does-not-enclose-namespace-itk/886/3 "2018-05-02T00:54:16Z")
Thanks Matt, is there any example of wrapping a free function, even if existing macros don’t cover it?
---
### Author:  [@matt.mccormick](https://discourse.itk.org/u/matt.mccormick)
#### Post date: [May 2, 2018, 2:09pm UTC](https://discourse.itk.org/t/python-wrapping-error-cannot-define-or-redeclare-x-here-because-namespace-wrappers-does-not-enclose-namespace-itk/886/4 "2018-05-02T14:09:39Z")
Nothing comes to mind.
It could be a `static` method of a class.
---
### Author:  [@phcerdan](https://discourse.itk.org/u/phcerdan)
#### Post date: [May 2, 2018, 2:31pm UTC](https://discourse.itk.org/t/python-wrapping-error-cannot-define-or-redeclare-x-here-because-namespace-wrappers-does-not-enclose-namespace-itk/886/5 "2018-05-02T14:31:57Z")
> [@matt.mccormick](#):
>
> It could be a static method of a class.
That sounds good, I am going to give it a try.
---
### Author:  [@phcerdan](https://discourse.itk.org/u/phcerdan)
#### Post date: [May 2, 2018, 2:47pm UTC](https://discourse.itk.org/t/python-wrapping-error-cannot-define-or-redeclare-x-here-because-namespace-wrappers-does-not-enclose-namespace-itk/886/6 "2018-05-02T14:47:19Z")
This is not possible either right?
```cpp
#ifndef itkViewImage_h
#define itkViewImage_h
#include
#include
namespace itk
{
class ViewImage {
template
static void View(const TImageType* img,
const std::string& win_title = "itkView",
size_t win_x = 600,
size_t win_y = 600);
};
}// namespace itk
#ifndef ITK_MANUAL_INSTANTIATION
#include "itkViewImage.hxx"
#endif
#endif
```
Instead of having a template class, template the static function and wrap it.
---
### Author:  [@phcerdan](https://discourse.itk.org/u/phcerdan)
#### Post date: [May 2, 2018, 2:51pm UTC](https://discourse.itk.org/t/python-wrapping-error-cannot-define-or-redeclare-x-here-because-namespace-wrappers-does-not-enclose-namespace-itk/886/7 "2018-05-02T14:51:22Z")
Maybe I can just create a single constructor with that function and template the class.
---
### Author:  [@phcerdan](https://discourse.itk.org/u/phcerdan)
#### Post date: [May 2, 2018, 2:54pm UTC](https://discourse.itk.org/t/python-wrapping-error-cannot-define-or-redeclare-x-here-because-namespace-wrappers-does-not-enclose-namespace-itk/886/8 "2018-05-02T14:54:51Z")
Or just template the class. But would python know the type when `itkViewImage.View(inputImage)` based on the input image without the need of explicitly write the type? Or would we need: `itkViewImage[ImageType].View(inputImage)`?
---
### Author:  [@matt.mccormick](https://discourse.itk.org/u/matt.mccormick)
#### Post date: [May 2, 2018, 3:04pm UTC](https://discourse.itk.org/t/python-wrapping-error-cannot-define-or-redeclare-x-here-because-namespace-wrappers-does-not-enclose-namespace-itk/886/9 "2018-05-02T15:04:58Z")
> [@phcerdan](#):
>
> itkViewImage.View(inputImage)
This currently requires the class to have a
- `SetInput` or `SetInputImage` or `SetInput1` method
- `UpdateLargestPossibleRegion` method
- `GetOutput` method
per:
>
---
### Author:  [@phcerdan](https://discourse.itk.org/u/phcerdan)
#### Post date: [May 2, 2018, 3:10pm UTC](https://discourse.itk.org/t/python-wrapping-error-cannot-define-or-redeclare-x-here-because-namespace-wrappers-does-not-enclose-namespace-itk/886/10 "2018-05-02T15:10:41Z")
Thanks Matt, I think I would have to set up the template from python. I prefer this simple viewer to be stateless.
---
### Author:  [@matt.mccormick](https://discourse.itk.org/u/matt.mccormick)
#### Post date: [May 2, 2018, 3:16pm UTC](https://discourse.itk.org/t/python-wrapping-error-cannot-define-or-redeclare-x-here-because-namespace-wrappers-does-not-enclose-namespace-itk/886/11 "2018-05-02T15:16:16Z")
Sounds good, Pablo.