[Insight-users] Passing ITK objects from Python to C code of a Python extension

[Sven Prevrhal]

Since there are apparently some issues with converting strings and vectors
of strings to/from Python and ITK and I have not figured out how to, from
Python, 
	- use DICOMSeriesFileNames to get a set of file names pertaining to
one SeriesUID
	- read it with ImageSeriesReader
	- Use ConnectITKToVTK to transfer the images over to VTK for
visualization

I thought I would write a Python extension that would accept a SeriesUID,
execute those steps and return a vtkImageData object to Python for further
processing. But I fail to figure out how to pass an ITK object to my
Python/C code.

I was thinking something like this for Python extension .cxx file - 

static PyObject *
PyITKHelloWorld_ITKHelloWorld(PyObject *self, PyObject *args)
{
	ImageType::Pointer argImage;
	PyObject * arg1;
 
    if (!PyArg_ParseTuple(args, "O", &arg1))
        return NULL;
	
	// THIS LINE DOES NOT COMPILE
	argImage= (itk::Image< unsigned short, 3 >::Pointer) arg1; 
...


and in Python,

im = itkImageUS3_New()
PyITKHelloWorld.ITKHelloWorld(im.GetPointer())

...


Needless to say, the code does not compile (can import my extension though,
and I have a very simple method without passing an ITK object that works
just fine, so the basics are OK). Am I completely off? Or what do I need to
do?

Thanks!

Sven